E-Bm, 36^ ^ ^ ^ ^ ^ ^ ^ ^
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DOE/ER-0580T

Summaries of FY 1992

Engineering Research

November 1992

U.S. Department of Energy

Office of Energy Research

Office of Basic Energy Sciences

Division of Engineering and Geosciences
Foreword

This report documents the BES Engineering Research Program for fiscal year 1992; it

provides a summary for each of the program projects in addition to a brief program

overview. The report is intended to provide staff of Congressional committees, other

executive departments, and other DOE offices with substantive program information so as

to facilitate governmental overview and coordination of Federal research programs. Of

equal importance, its availability facilitates communication of program information to

interested research engineers and scientists. The organizational chart for the DOE Office

of Energy Research (OER) on the next page delineates the six Divisions within the OER

Office of Basic Energy Sciences (BES). Each BES Division administers basic, mission

oriented research programs in the area indicated by its title. The BES Engineering

Research Program is one such program; it is administered by the Engineering and

Geosciences Division of BES. Dr. Oscar P. Manley is technical manager of the

Engineering Research Program; inquiries concerning the program may be addressed to

him, in writing or by phone at (301) 903-5822.

In preparing this report we asked the principal investigators to submit summaries for their

projects that were specifically applicable to fiscal year 1992. The summaries received have

been edited if necessary, but the press for timely publication made it impractical to have

the investigators review and approve the summaries prior to publication. For more

information about a given project, it is suggested that the investigators be contacted

directly.
ENGINEERING RESEARCH PROGRAM WITHIN DOE

Secretary of Energy

Deputy Secretary

Under Secretary

Assistant Secretaries Office of Ener Federal Energy Research gulatory · Nuclear Energy Commission · Conservation and Renewable * Economic Regulatory · Fossil Commission

* Defense * Energy Information · Environment, Safety & Health Administration · Environmental Restoration * International Affairs, etc.

II

* Program Analysis Basic Energy Sciences Management * Magnetic *Magnetic Fusion Fusion I -I · Management * Special Programs High Energy and Nuclear Physics * Scientific Computing * Health and Environmental Research Science and Technology Advisor

* Field Operations Field Operations · Science and Technology Advisor

* Material Sciences Division Engineering and * Advanced Energy Projects * Chemical Sciences Division Geosciences Division * Energy Biosciences

Engineering

Research Program
Introduction

The individual project summaries follow the program overview. The summaries are

ordered alphabetically by name of institution and so the table of contents lists all the

institutions at which projects were sponsored in fiscal year 1992.

The projects are numbered sequentially for individual identification in the indexes. Each

project entry begins with an institutional-departmental heading. The names of investigators are listed immediately below the title. The funding level for fiscal year 1992

appears to the right of title; it is followed by the budget activity number (e.g.,01A). These

numbers categorize the projects for budgetary purposes and the categories are described

in the budget number index. The year in which either the project began or was renewed

and the anticipated duration in years are indicated respectively by the first two and last

digits of the sequence directly below the budget activity number (e.g., 90-3). The

summary description of the project completes the entry.
Program Review

BES Engineering Research

The BES Engineering Research Program is one of the component research programs which

collectively constitute the DOE Basic Energy Sciences Program. The DOE Basic Energy

Sciences program supports energy related research in the physical and biological sciences,

and in engineering. The chief purpose of the DOE Basic Energy Sciences Program is to

provide the fundamental scientific base on which identification and development of future,

national energy options will depend. The major product of the program becomes part of

the body of data and knowledge upon which the applied energy technologies are founded;

the product is knowledge relevant to energy exploration, production, conversion and use.

The BES Engineering Research Program was started in 1979 to help resolve the numerous

serious engineering issues arising from efforts to meet U.S. energy needs. The program

supports fundamental research on broad, generic topics in energy related engineering topics

not as narrowly scoped as those addressed by the shorter term engineering research projects

sponsored by the various DOE technology programs. Special emphasis is placed on

projects which, if successfully concluded, will benefit more than one energy technology.

During the first year several workshops were sponsored for the purpose of identifying

energy related engineering research needs and initial priorities. Representatives from

industry, academic institutions, national laboratories, and leading members of professional

organizations (Engineering Societies Commission of Energy, American Society of

Mechanical Engineers, Society of Automotive Engineers, and Joint Automation and Control

Committee) participated in the workshops. In addition to the participants in the workshops,

staff representatives from the DOE technology programs and other leading U.S. energy

engineering experts made significant contributions to the setting of program priorities.

There resulted from this process a strong confirmation of the need for a long range,

fundamental engineering research program with two major goals. The broad goals that

were established by this process for the BES Engineering Research Program are:

1) To extend the body of knowledge underlying current engineering practice so as to

create new options for enhancing energy savings and production, for prolonging useful

equipment life, and for reducing costs without degradation of industrial production and

performance quality; and

2) To broaden the technical and conceptual base for solving future engineering problems

in the energy technologies.
In this process, it was further established that to achieve these goals, the BES Engineering

Research Program should address the following topics identified as essential to the progress

of many energy technologies:

1) Advanced Industrial Technology: improvement of energy conversion and utilization,

opening new technological possibilities, and improvement of energy systems.

2) Fluid Dynamics and Thermal Processes: broadening of understanding of heat transfer

in nonsteady flows, methodology for reducing vibrations and noise in heat exchangers, and

engineering aspects of combustion.

3) Solid Mechanics: continuum mechanics, fracture mechanics, thermomechanical

behavior in severe environments, aging & lifetime reliability of structures.

4) Dynamics and Control of Processes and Systems: development and use of information

describing system behavior (system models), performance criteria, and theories of control

optimization to achieve the best possible system performance subject to known constraints.

A Scoping Workshop held in December, 1985 confirmed the continued needs for research

in these topical areas. Because of budgetary limitations, the implemented BES Engineering

Research Program is somewhat less broad than the program envisioned above. At present,

equal emphasis is being placed in three carefully selected, high priority research areas;

namely,

1) Mechanical Sciences including fluid mechanics (multiphase flow and turbulence) heat

transfer, and solid mechanics (continuum mechanics and fracture mechanics).

2) System Sciences including process control and instrumentation.

3) Engineering Analysis including nonlinear dynamics, data bases for thermophysical

properties of fluids, modeling of combustion processes for engineering application, and

foundations of bioprocessing of fuels and energy related wastes.

These areas contain the most critical elements of the four topics enumerated above; as such

they are of importance to energy technologies both in the short and long term, and

therefore of immediate programmatic interest. It should be noted that other areas of basic

research important to engineering are monitored elsewhere in BES. For instance,

separation sciences and research on thermophysical properties are among the

responsibilities of the Chemical Sciences Division, while microscopic aspects of fracture

mechanics are in the domain of the Material Sciences Division. As resources permit, other

high priority areas are being added to the Engineering Research Program. Thus, as a result

of previous growth in the program budget an important development took place in the

Engineering Research Program: two major concentrations of research were initiated.
First, a new program was organized at Oak Ridge National Lab dealing with intelligent

machines in an unstructured environment. Some resources are available for coordinated,

more narrowly focussed, related, high quality research at universities and other research

centers. All such activities are supported and administered directly by the Engineering

Research Program, but some coordination of efforts with the ORNL program may prove

useful.

Secondly in FY 1985, a collaborative research effort was started between MIT and Idaho

National Engineering Lab. At present, the collaboration is in three distinct areas: Plasma

Process Engineering, Automated Welding, and Fracture Mechanics. Collateral, high quality

research efforts at other institutions are supported by the Engineering Research Program.

In the expectation of a future modest growth of this Program, two International Workshops

on Two Phase Flow Fundamental were held one in September 1985 and the other in

March, 1987. The meetings were used to identify basic research needs in the field of two

phase flow and heat transfer; summary reports of the workshops are available from the

Program Office. The proceedings of the two workshops have been published as volumes

in the series "Advances in Heat and Mass Transfer" (Hemisphere Publishing Company).

A third international workshop held in June 1992 surveyed the status of the field. The

proceedings will be published by CRC Publishing Company.

Two additional workshops were held during 1988. The first dealt with possible research

opportunities in the field of novel devices using the new high temperature superconductors.

The second addressed research needs for bioprocessing of fuels and energy related wastes.

Reports of both workshops have been published. Additional funds have been provided in

FY 1992 to initiate research in the above mentioned bioprocessing area. Of interest are

relevant studies at the intersection of biology, biochemistry, and chemical engineering.

Another workshop aimed at identifying research opportunities to mitigate the effects of

aging in energy production and distribution systems took place in October 1992. The

proceedings will appear in Applied Mechanics Reviews.

It should be mentioned too, that some very limited support is available for research on

large scale systems. A report of a workshop on needs, opportunities, and options in this

field is available from Professor G.L. Thompson, Graduate School of Industrial

Administration, Carnegie-Mellon University, Pittsburgh, PA 15213. Also there is some

interest in addressing the basic foundations of advanced manufacturing processes. In this

context twelve three-year doctoral fellowships administered by National Academy of

Science and National Research Council have been sponsored.

Research projects sponsored by the BES Engineering Research Program are currently

underway at universities, private sector laboratories, and DOE national laboratories. In

fiscal year 1992 the available program operating funds available amounted to about $16.4

million. The distribution of these funds among various institutions and by topical area is
illustrated on the next page. Project funding levels are mostly in the range of $50,000 to

$150,000 per year. Typical duration of a project is three to four years, with some projects

expected to last as long as ten years or more. The BES Engineering Research projects

stem almost without exception from grant applications. Applications which anticipate

definite results in less than two years are usually referred to the appropriate DOE

technology program for consideration. All those interested in submitting a proposal are

encouraged to discuss their ideas with the technical program manager prior to submission

of a formal proposal. Such discussion helps to establish whether or not a potential project

has a reasonable chance of being funded. The primary considerations for possible support

are the technical quality of the proposal and the professional standing of the principal

investigators and staff. An effort is made to attract first rate, younger research engineers

and energy oriented applied scientists. A high technical caliber of research is maintained

by requiring that the projects supported have potential for a significant contribution to

energy related engineering science, or for an initial contribution to a new energy relevant

technology. Sponsored projects are selected primarily for their relevance to DOE mission

requirements; the contribution to energy related graduate education is an important

consideration. Thus projects sponsored at universities are essentially limited to advanced

theoretical and experimental studies usually performed by faculty members, staff research

scientists, and doctoral candidates.
ENGINEERING RESEARCH PROGRAM

FY '92 BUDGET ($000's)

BY INSTITUTIONAL TYPE

NATIONAL /UNIVERSITIES LABORATORIES \ 58.5% 25.6% \ $954 $9542 $4168$416 .» ^\ (95 Projects) (17 Projects) P

OTHER

15.9%

$2600

(13 Projects)

ENGINEERING RESEARCH PROGRAM

FY'92 BUDGET

BY TECHNICAL AREAS

($000 S) % NUMBER OF PROJECTS

MECHANICAL SCIENCES 4975 30.5 49

SYSTEMS SCIENCES 5160 31.6 28

ENGINEERING ANALYSIS 6176 37.9 48
Table of Contents

University of Alabama ............................... 1

Argonne National Laboratory ........................... 1

Arizona State University .............................. 2

Battelle Memorial Institute ............................. 2

University Of California, Berkeley ....................... 3

University Of California, Los Angeles ..................... 4

University Of California, San Diego ...................... 4

University Of California, Santa Barbara ................... 7

California Institute Of Technology ....................... 8

Carnegie Mellon University ............................ 8

University Of Chicago ............................... 10

Clarkson University ................................ . 11

University Of Connecticut ............................. 11

Cornell University .................................. 12

Dartmouth College .................................. 13

Duke University ................................... 14

Engineering Science Software, Inc ........................ 11

Idaho National Engineering Laboratory .................... 14

University Of Illinois ................................ 17

University Of Illinois At Chicago ........................ 18

Jet Propulsion Laboratory .. .................... ....... 18

Johns Hopkins University ............................. 18

Robert H. Kraichnan, Inc. ............................. 19

Lawrence Berkeley Laboratory .......................... 19

Lovelace Medical Foundation ........................... 20

University Of Maryland .............................. 20

University Of Massachusetts ........................... 22

University Of Massachusetts-Lowell ...................... 23

Massachusetts Institute Of Technology .................... 23

University Of Minnesota .............................. 28

National Academy of Sciences/National Research Council ....... 28

National Institute Of Standards And Technology .............. 29

The City University Of New York, The City College .......... 30

Northwestern University .............................. 31

University Of Notre Dame ............................. 33

Oak Ridge National Laboratory ......................... 34

Ohio State University ............................... 35

Oregon State University .............................. 36
Table of Contents (continued)

Pacific Northwest Laboratory ........................... 37

University Of Pennsylvania ............................ 37

Pennsylvania State University ................. .......... 37

Physical Sciences Inc ................................ 38

Princeton University ................................. 38

Purdue University .................................. 39

Rensselaer Polytechnic Institute ......................... 40

Rice University .................................... 42

University Of Rochester .............................. 42

Rockefeller University ................................ 43

Sandia National Laboratories ........................... 43

University Of Southern California ........................ 44

Southwest Research Institute ........................... 45

Stanford University ................................. 45

Stevens Institute Of Technology ......................... 49

University Of Texas At Austin .......................... 49

Tufts University .................................. 50

United Technologies Research Center ..................... 50

Washington University ............................... 51

Washington State University ........................... 51

University Of Wisconsin .............................. 52
University Of Alabama Argonne National Laboratory

Dept of Mathematics $54,126 Materials & Components Tech Div $139,800

Tuscaloosa, AL 35487 01-C Argonne, IL 60439 01-A

91-3 90-3

Hydrodynamic Instabilities and Coherent Chaos in Fluid-Structure Systems

Structures S. Chen, T. Mulcahy

A. Frenkel

Integrated theoretical and experimental studies are

The objective of this project is to advance the being performed to enhance the understanding of

understanding of instabilities of several fluid nonlinear oscillations and dynamic instability

systems relevant to energy engineering sciences. phenomena involving both fluids and solid

Some problems, approaches to their solution, and structures and their coupling. The objectives are

results follow. to contribute to the explanation of observed

phenomena, providing insights into chaotic

For the problem of coherent structures and the characteristics of such coupled mechanical

inverse energy cascade in turbulent flows, both systems and ultimately, to the solution of

statistical ensembles and deterministic periodic engineering design problems. This is a joint

flows are considered. project with Professor F. Moon at Cornell

University.

It is found that an isotropic turbulent flow is stable

to the mean-flow perturbations. This suggests Fluidelastic instability of loosely supported tubes,

that some statistical anisotropy is necessary for vibrating in a tube support plate-inactive mode, is

the growth of the coherent structures. suspected to be one of the main causes of tube

failure in some operating steam generators and

The same techniques, based on mathematical heat exchangers. As a vehicle to understand the

insights into the properties of functionals of nonlinear behavior of fluid-structure systems,

Gaussian processes, yields a new description of fluidelastic instability of loosely supported tube

the diffusion of a passive scalar - such as the rows in crossflow is being studied in detail. A tube

temperature - in a turbulent flow. row with a motion-limiting stop configuration is

being tested to investigate various response

For a deterministic unidirectional flow with a characteristics and a mathematical model based

sinusoidal profile of velocity, it is shown rigorously on the unsteady flow theory has been developed

- by using continued fractions - that some to predict the response characteristics of this

perturbations which do not have the same classical fluid-structure system. Other

periodicity as the basic flow, can nevertheless fluid-structure systems such as coupled stack/wire

grow. The much more complicated case when the dynamics due to wind excitations will also be

flow is, in addition, sinusoidal in time is reduced to investigated.

an infinite algebraic eigenvalue problem. Its

Galerkin approximation results are not restricted to Energy systems have had a history of dynamic

large scales, in contrast to earlier results. An structural instabilities caused by fluid flow resulting

exact solution of a generalized Orr-Sommerfeld in costly component repair and replacement and

equation in the inviscid case is found and loss of energy production. The understanding of

compared to the Galerkin-based results. dynamic characteristics, including periodic

oscillations, random vibration, and chaotic motion,

For the core-annular flow - important in the will impact the design and reliability of these

lubricated pipelining of heavy oils - a new systems in both the near and long term. In

nonlinear interface equation is derived. It reflects addition, fluid-structure systems are classical

the dynamics of the core in addition to the examples of autonomous systems that can exhibit

dynamics of the lubricating film. Several domains chaotic behavior. Knowledge of the fluid-structure

of basic parameters are indicated in which the systems may provide some insights into the

instability cannot break up the flow. The finite but chaotic behavior of other energy system

small oscillations of the interface can have the components.

character of either deterministic chaos or else a

nonlinear propagating wave.

Engineering Research1 1992 '*v~~~~~~~~,
Argonne National Laboratory initial exploration of the use of Preisach model in

Materials & Components Tech DIv $137,000 fatigue analyses.

Argonne, IL 60439 01-A

90-3 90-3 The studies of critical states were concentrated on

Bounds on Dynamic Plastic Deformation fundamental issues such as the determination of

C. Youngdahl the proximity parameter, universal parameters, order parameter and differences between the

Analytical studies are being performed to develop elastic and traditional (conduction) percolation

methods for approximating or bounding the problems. It was demonstrated that the second

dynamic plastic deformation of structures. In order phase (connectivity) transition takes place

many applications where the load is transmitted to only in stress (load) controlled conditions. In

the structure through a fluid, details of the load contrast, localization (emergence of shear bands)

history and spatial distribution significantly affect of the deformation occurs in the strain

the final plastic deformation. The objective of the (displacement) controlled tests. It was shown that

program is to devise mode approximation methods the proximity parameters can in fact be formulated

and load correlation parameters which can be in terms of the Budiansky, O'Connell damage

used to predict the final deformed shape and parameter.

characterize the effects of the load without

resorting to detailed numerical analyses. These Initial exploration of the Preisach model were

approximation methods have three important uses: focused on ductile behavior using parallel bar

to perform design and safety analyses of models. Important conclusions were related to the

structures over a wide range of design variables thermodynamics of the process, including

and loadings; to validate computer programs which differences between locked-in and dissipated

have a nonlinear dynamic plasticity capability; and work. It seems tht the Preisach model may be

to correlate experimental simulations with actual or very suitable for studies of the fatigue problem.

predicted events. This work will require significant modifications of

the original model.

The dynamic plastic deformation of some basic

structural configurations are being analyzed for

loadings which vary both in magnitude and region Battelle Memorial Institute

of application with time. Mode approximation Mechanics Dept $94,027

methods and load correlation parameters are Columbus, OH 43201-2693 01-A

hypothesized and their usefulness in predicting 90-3

final plastic deformation is determined. The An Investigation of the Effects of History

methods, based initially on a rigid, perfectly plastic Dependent Damage In Time Dependent

material model and small deformation response, Fracture Mechanics

are extended to include strain hardening, an initial F. Brust, Jr.

elastic response period, and large deformation

interactions. The demands for structural systems to perform

reliably under severe operating conditions continue

to increase. Modern energy production facilities

Arizona State University experience degradation and damage because they

Mechanical & Aerospace Eng $60,000 operate in a severe high-temperature environment

Tempe, AZ 85287 01-A where time dependent straining and damage may

92-4 lead to structural failures. The goal of this

Continuous Damage Mechanics - Critical research is to study the high temperature damage

States and failure processes and to further develop a

D. Krajclnovlc method for predicting this behavior in an effort to

increase structural life. In particular, we focus on

The research during the fourth, and last, year of time dependent damage which occurs under

the research was focused almost entirely on the history-dependent loading conditions, i.e. transient

two tasks: (a) response of microcrack weakened conditions.

solids in the vicinity of the critical state, and (b)

Engineering Research 2 199
The types of time dependent (creep) damage details of the sheath motion, the enhancement

considered in this program include: sustained load factor of the stochastic heating can change, and

creep, variable load creep, and variable load creep consequently so can the ratio of electron to ion

with thermal gradients. During the first year of this power at a given overall power level. The

study, the implications of using Norton's creep law measured results, together with measurements of

on various integral parameters used to other plasma parameters, will be used to construct

characterize crack tip phenomena were evaluated better predictive models of discharge behavior and

as a function of time. Other constitutive laws for parameter scaling.

time dependent materials such as those of

Murakami and Ohno are being implemented into Stochastic heating can be enhanced with a

the finite element code. In addition, constitutive resonant helical discharge structure. This

property data and high temperature creep crack geometry is of importance for materials processing

growth data are being obtained on stainless steel. applications and is under investigation as part of

These experiments will be used to verify analytical the overall program to understand plasma heating

predictions and characterize time and history and develop models of r.f. processing discharges.

dependent damage during crack nucleation and

growth.

University Of California/B

The results from this work will be used during the Dept of Mechanical Engineering $120,603

design phase by practicing engineers to enhance Berkeley, CA 94720 01-B

the life of high temperature structural systems. 92-3

Thermal Radiation and Conduction In

Mlcroscale Structures

University Of California/B C.-L Tien

Dept of Electrical Engineering $97,000

& Computer Sciences 06-C Micro- and nanometer scale devices are

Berkeley, CA 94720 90-3 becoming more and more prevalent in energy

related applications. The rapid acceptance of

Self-Generated Stochastic Heating In an RF microelectronics as commonplace control and data

Discharge processing elements makes the systems using

A. Uchtenberg, M. Ueberman them vulnerable to heat instabilities. It is therefore

of crucial importance to understand how heat is

The purpose of this project is to study electron transported by radiation and by conduction on

heating mechanisms in radio frequency (r.f.) micro- and nanoscales. From the basic point of

discharges. These discharges are used view problems arise because some of the

extensively by industry for surface modification of characteristic lengths arising in heat transfer are

electronic and mechanical materials. In addition to not small as compared with the dimension of the

the usual r.f. ohmic heating in the plasma interior, heated or cooled objects, unlike the case usually

it has been found theoretically that stochastic encountered in heat transfer.

heating at the plasma surface plays a major role.

The stochastic electron heating arises from The proposed research is divided into three

successive decorrelated reflections of electrons complementary parts:

with the oscillating sheath near the surface of the

discharge. Power is also transferred directly to the 1) Radiative properties of microstructures.

ions by acceleration in the sheaths. The efficiency Because of the small size of the objects of

of stochastic heating depends on the detailed interest, it is expected that partial coherence

sheath dynamics. For a low pressure discharge at theory of light will play a role in the emission of

a pressure of 3 mTorr, power of 100 watts, and radiation by the small devices. To use that theory

frequency of 13 MHz, 95% of the electron heating it has to be suitably generalized. At the same time

is predicted to occur stochastically. microstructures themselves have significant effects

on the optical constants. Experiments and

The sheath dynamics are being measured and analysis will be carried out to characterize those

related to the predicted stochastic heating for a effects on the optical constants.

plane parallel argon discharge. Depending on the

Engineenng Hesearcn 3 1992
2) Radiative heat transfer in microstructures. common non-structured porous media show good

Since the dimensions of microstructures are often agreement for Re > 10.

comparable with the wavelengths typical of the

radiated spectrum, geometrical optics may fail, and Results have been obtained using one - and twothe intrinsic wave nature of the field must be taken temperature turbulent transport models and

into account. Theoretical studies will be carried comparison with effective coefficient oneout to determine how such phenomena as temperature models will be made. Models have

interference and diffraction affect radiative heat been developed for turbulent flow in a duct with

transfer. roughness developed from regular two dimension

shapes like ribs, rods, spheres and trapezoids.

3) Conductive heat transfer in microstructures. These models demonstrate the sensitivity of

Unlike previous related work, here the size effects transport phenomena to the surface morphology of

on heat conduction in multilayer films will be the solid surfaces whether a duct wall or interstitial

studied. Again both theoretical and experimental space boundaries within the porous media.

studies will be carried out. Of special note is the Methods of experimental confirmation are being

attempt to measure more reliably heat conduction developed for such regular morphology in porous

in thin films, an area of experimental science media and other surfaces.

which needs much more development.

University Of California/LA

University Of California/LA Physics Dept $79,000

Mech, Aero & Nuclear Eng Dept $90,024 Los Angeles, CA 90024 06-C

School of Eng & Applied Science 01-C 90-3

Los Angeles, CA 90024-1597 92-3 Wave Turbulence and Self-Localization In

Continuous Media

Basic Studies of Transport Processes In S. Putterman

Porous Media

I. Catton The fate of energy which is injected into fluids that

are far from equilibrium is being investigated from

The research covers two broad areas: single and the experimental, theoretical and computational

two-phase convection in porous media. The point of view. These off-equilibrium systems can

objective of this study is to develop physical display a tendency to a) form structures b) develop

understanding of the governing phenomena and a stochastic spectrum of energy and c) focus

models for prediction of transport processes by energy. Regarding a) the formation of solitons,

theoretical and experimental means. domain walls and kinks in continuous media is

being studied. Regarding b) the tendency of a

A systematic development of models for turbulent spectrum of acoustic motion to become wave

transport in porous media with regular morphology turbulent is being investigated and regarding c) the

is underway. Methods have been developed to transduction of sound into light is being measured.

close the integral terms in the turbulent transport This last phenomenon results from a self-focusing

equations that depend on the geometrical structure instability that concentrates energy by a factor of

of the media. A tridiagonal non-monotonic one trillion.

algorithm has been designed to improve the

numerical accuracy of the "one-temperature"

model equation with irregular 3-nd kind boundary University of California/SD

conditions for a highly porous medium. Scripps Inst. of Oceanography $165,000

La Jolla, CA 92093-0402 06-C

Theoretical models for flow resistance and heat 90-4

transfer have been developed for porous media Nonperiodic, Broadband Signals:

with capillary and globular morphology (tubes, slits Signal Processing in Chaos

and beads free of interacting) that are valid over a H Abarbanel

wide range of parameters. Comparisons of the

results obtained for these canonical models with We are investigating methods for modeling fluid

coefficients of drag resistance and heat transfer for ows and plasa dynamics of relevance to energy

Engineering Hesearch 4 1992
problems when these physical phenomena exhibit set up and is undergoing initial testing so that a

motion on fractal objects called strange attractors. more complete set of data on droplet behavior in

In these cases, which are quite common both in these streams will be obtained shortly. In addition

the settings indicated, and in electrical circuits and the initial theory is being refined and improved.

condensed matter systems, the time series have Attention is also being devoted to the applicability

continuous broadband power spectra and quite of the spray equation to counterflowing streams

irregular behavior. We are engaged in methods since there appear to be both theoretical and

for identifying the space in which to work for these experimental difficulties arising when the droplet

systems (phase space reconstruction), methods velocity goes to zero.

for computing the invariants of the motions, and

methods for making physical models for prediction

in these irregular systems. These systems are University Of California/SD

inherently less predictable than familiar linear Department of Chemistry, 0340 $183,512

systems, but their predictability is nonzero and L Jolla, CA 92093 06-C

may be extracted in a systematic fashion from the 92-4

time traces themselves. Noisy Nonlinear Systems

K. Undenberg The work has concentrated on methods to extract

chaotic, deterministic signals from noisy Transport and reactions on fractals occur in many

measurements. The noise may be due to natural phenomena including geological processes

environmental conditions or measurement errors and processes in the solid state or on surfaces.

or may have been imposed on purpose to mask Our efforts have been directed toward gaining a

the signal. With these "cleaning" tools, we will theoretical understanding of these processes.

clean up laboratory and field data for use in the

other parts of the signal processing effort. The time that it takes a walker to reach a given

point on a fractal is relevant for events that are

triggered when an excitation or molecule or charge

University Of California/SD reaches a designated point. Our analysis is based

Dept of App Mech & Eng Scl $126,000 on a renormalization approach that yields exact

La Jolla, CA 92093 06-B results on some deterministic fractals. Whether

90-3 these methods can be generally applied to random

Experimental and Theoretical Study of Fuel fractals is still an open question; we have applied

Droplets Subject to a Straining Flow them to certain classes of random fractals.

P. Libby, F. Williams

The rates of even the simplest diffusion-controlled

This research involves a combined experimental reactions in low-dimensional (including fractal)

and theoretical effort related to the behavior of fuel systems behave very differently than the standard

droplets in well defined but nonuniform flows. Our law-of-mass-action descriptions and have been

current research concerns fuel sprays in called "anomalous" and indicative of "mathematical

counterflowing streams which result in flat poisoning." Our calculation of reaction rates is

nonpremixed flames. A test rig which permits a based on scaling arguments that lead to

wide variety of investigations including parametrized results. Even this limited success

nonpremixed. premixed and partially premixed has provided a great deal of insight.

systems has been put into operation. Initial results

involve a study of the extinction characteristics of We continue to make progress in the (unrelated)

these flames. A contribution including related problem of the effect of colored noise on the

theoretical work has been accepted for evolution of a system. We have obtained analytic

presentation at, and publication in the proceedings results for a dye laser driven by Gaussian

of, the International Combustion Symposium in fluctuations and also for bistable systems driven

Sydney. A phase doppler system permitting by dichotomous noise and by monochromatic

droplet size, two components of velocity and noise.

droplet population to be measured has now been

Engineering Research 5 1992
University Of California/SD University Of California/SD

Pure & Applied Physical Science $98,000 Inst for Nonlinear Science, R-002 $94,458

La Jolla, CA 92093 06-C La Jolla, CA 92093 06-C

91-2 91-2

Knot Invariants and the Thermodynamics Formation of Three-Dimensional

of Lattice Gas Automata Slngularitles, Regularizatlon Procedures and

D. Meyer Markovian-Multifractal Description of

Turbulent Flows

Some discrete models for dynamical systems (like E. Novlkov

lattice gas hydrodynamics) exhibit approximately

thermodynamic behavior despite the presence of A new approach to the problem of turbulent flows

conserved quantities other than the energy/ with high Reynolds number is developed. This

momenta and even for small system size (e.g., the approach is based on the conditional averaging of

lattice gas models for two phase flow through hydrodynamics equations for local characteristics

porous media). The goal of this project is to build with self-amplification (vorticity field in 3-D

on the understanding of the connections between turbulence and vorticity gradient in 2-D

knot invariants, exactly solvable statistical turbulence). Some new exact results are obtained

mechanics models and discrete dynamical by this approach. The concept of conditional

systems gained in earlier work (appearing in averaging is also applied to sub-grid modelling of

Physica J and the Proceedings of the International turbulence for large-eddy simulations. Additional

Conference on Knot Theory and Related Topics, progress is made by a Markovian description of

Osaka, Japan, 1990) toward an answer to the two-point characteristics of turbulence with the

question of how this early and robust use of breakdown coefficients. Preliminary

thermodynamic behavior occurs in lattice gas numerical experiments for the formation of

automata. singularities in viscous turbulent flows are

performed. New results are also obtained for the

The basis of the approach is exemplified by the chaotic vortex-body interactions.

result that one specific reversible cellular

automaton model with a conserved quantity is

equivalent, in the sense that the ensemble of 1 + University Of California/SD

1 dimensional spacetime evolutions is the same as Dept of Physics $ 0

the equilibrium ensemble of 3 dimensional La Jolla CA 9093 01-B

configurations, to a solvable statistical mechanics 90-3

model at a critical point. In addition to the Traveling-Wave Convection In Fluid Mixtures

association between the critical limit of solvable C Surko

models and knot invariants, the physical

characteristics of the critical point are consistent While much progress has been achieved in

with the canonical distribution observed in understanding the dynamics of free convection in

simulations. single-component fluids, much less is known

about convection in fluid mixtures, yet in many Current work includes the application of this realistic situations, the latter plays an important

approach to a family of 1 dimensional lattice gas role. Examples of interest to engineering include

automata based on a model of 't Hooft. The the stability of doubly-diffusive systems such as

intention is also to study the relation between the solar ponds, the solidification of metal alloy casts,

lattice gas analysis of this model and t Hooft's and convection in fuel droplets.

defect/curvature interpretation. The same

framework will also be applied to other one This research program addresses the role of

dimensional models such as the cellular traveling-waves in the dynamics of convective

automaton for Burger's equation. In addition one flows in fluid mixtures. Even in a relatively simple

would like to begin investigating higher experiment, the behavior of the system is such

dimensional models, though this is expected to be that, by varying one or two control parameters, the

much more difficult. whole gamut of states ranging from laminar

Engineering Research 6 1992
traveling-waves to well developed turbulence can flow patterns. The technique can detect the flow

be explored. For example, in one experimental field even when the convection threshold is

setup, a narrow annular channel is filled with a exceeded by only 0.1%. In parallel,

water-ethanol mixture and heated from below to high-resolution heat-flux measurements are made

produce free convection. For a range of with a resolution of 0.05%. Thus, the relationship

parameters, this convective flow occurs in a between the pattern and the heat transport can be

pattern of traveling-waves, in the form of moving studied in great detail.

convective rolls, which propagate around the

annulus. The resulting oscillatory convection In pure fluids, we are investigating the

exhibits a wide range of phenomena. One striking mechanisms for the convective onset. In most

example is the occurrence of confined states, physical systems the flow is initiated by properties

where regions of convection, confined to just a of the experimental cell which lead to an imperfect

portion of the annular channel, co-exist stably with bifurcation. Recently it has been possible,

regions of quiescent fluid, even for uniform however, to perfect the apparatus to a point where

spatially values of the control parameter. In this stochastic effects control the evolution of the flow.

case, we now understand that these convecting

regions are stabilized by currents of concentration Beyond the convective threshold we are interested

associated with the traveling-waves. The nature in the evolution and stability of various convective

of convection in such mixtures is expected to be patterns in containers with simple sidewall

prototypical of effects arising in many contexts, geometries. We expect that our results will help in

ranging from oceanic flows to instabilities in liquid the development of theoretical models for pattern

crystals. stability.

Current research focuses on three related topics: A particularly interesting pattern-stability problem

measurement of the concentration field, study of occurs in binary-mixture convection. For certain

the mechanisms of wavelength selection in one- values of the parameters of this system, there

dimensional traveling patterns, and study of exist spatially localized patches of travelling waves

traveling-wave patterns in large-aspect-ratio, of convective rolls. The existence of these states

two-dimensional geometries. cannot be explained by the usual models with

relaxational dynamics, but rather seem to require

non-potential theories. We are studying

University Of California/SB quantitatively the wavenumber, frequency,

Dept of Physics $130,000 amplitude, and spatial extent of these localized

Santa Barbara, CA 93106 06-C states. This information will permit a distinction

90-3 between several competing theoretical models.

Bifurcations and Patterns in Nonlinear

Dissipative Systems

G. Ahlers, D. Cannell University Of California/SB

Dept of Chemical & Nuc Eng $ 0

This project consists of experimental investigations Santa Barbara, CA 93106 01-C

of non-linear non-equilibrium fluid-mechanical 91-3

systems, with an emphasis on heat transport, Turbulence Structure and Transport

pattern formation, and bifurcation phenomena. Processes In Wavy Liquid Streams

These issues are being studied in Rayleigh- S. Banerjee, G. Hetsroni

Benard convection, using both pure and

multi-component fluids. They play an important The first series of experiments in this program was

role in such energy-related issues as crystal to visualize wave-turbulence interactions near the

growth from a melt with and without impurities, the shear-free gas-liquid interface. Waves were

catastrophic inversion of salt lakes such as the generated mechanically with different wavelength

Dead Sea, energy production in solar ponds, and and amplitude without imposed shear at the

various oceanographic phenomena. interface to observe the effect of the waves on the

underlying turbulence structure.

The work utilizes computer-enhanced

shadowgraph imaging to visualize the convective

Engineering Hesearch 7 1992
Oxygen bubble tracers lit by a laser sheet of light process to be controlled. The objective of this

were imaged with high speed videography and research program is the development of a range of

single frame techniques. Turbulence quantities new modeling techniques, in particular:

such as the mean velocity profiles, turbulence development of techniques for building physicsintensities, Reynolds stresses and turbulence based, low order, nonlinear models with physically

production were evaluated near the interface. A meaningful parameters, specifically for the purpose

paper has been submitted to Physics of Fluids of (robust) linear and nonlinear controller design;

summarizing these data. and development of methods for the identification

of linear black box models and the associated

Detailed measurements of these values within uncertainty description suitable for robust control

waves will be taken using the three-dimensional system design.

LDA with an ultrasonic gauge to define the

instantaneous LDA distance from the interface. This research program emphasizes methods that

This work will clarify the identification of bursts are both mathematically lucid and industrially

within the surrounding fluid by using the flow effective. For example Partial Least Squares

visualization method to do conditional sampling of (PLS) has been highly regarded by practitioners

LDA data. When suitable criteria are isolated we although the relationship between PLS and other

will no longer have to rely on the visualization established regression methods has been

technique. incomplete. A firm mathematical link has been

developed between PLS and statistical

From a preliminary evaluation of the data already significance testing. Based on these new results,

obtained it appears that the absolute value of the PLS can now be used to generate uncertainty

triple correlation between the three velocity descriptions relevant for robust control, PLS's

fluctuation components, i.e. / u'v'w' / is a positive performance advantages are clearer, and PLS can

indicator of bursting motions. be applied to more general models.

Finally the contribution of surface waves versus

bursting events to turbulence will be differentiated Carnegie Mellon University

and compared for each run. To support the Chemical Eng Dept & Graduate $160,000

physical experiments, a program of direct solution School of Indus Admin 03-A

of the Navier-Stokes equations will be continued Pittsburgh, PA 15213 89-4

using the pseudo-spectral method. With the new

program we will incorporate free surface boundary Integration of Redesign Methodologies for

conditions that allow the 2D wave trains of Chemical Processes

constant shape to be considered, and we have L Biegler, I. Grossmann, G. Thompson, A.

incorporated a scalar field (temperature or Westerberg

concentration) that will allow a computational

assessment of relationships, if any, between Process redesign, commonly known as retrofit, is

large-scale flow structures and rates of heat and a major task in the chemical industries. However,

mass transfer. most systematic design strategies have been

developed for new process and often do not apply.

This project addresses the development of

California Institute Of systematic design methodologies for the redesign

Technology of chemical processes. This integrated approach

Chemical Engineering 210-41 $126,144 deals with a broad range of problems in process

Pasadena, CA 91125 03-A redesign. Here we discuss progress in the

91-3 following areas:

Modeling for Process Control

M. Morarl 1) Development of Efficient Optimization

Algorithms for Discrete and Continuous Variables.

One key difficulty which stands in the way of Efficient decomposition strategies for nonlinear

application of many advanced control techniques programming have been developed for large-scale

in the chemical process industries is the need for process optimization. These are currently being

a model to describe the dynamic behavior of the tailored to vrious problem types including

Engineering Research 8 1992
optimization problems in distillation, parameter program SYNHEAT is under development for the

estimation and data reconciliation. The work also implementation of these models.

includes the solution of several large scale

combinatorial optimization problems thatfrequently (4) Redesign for flexibility and reliability. The

occur in chemical engineering applications, expected stochastic flexibility, a new measure that

namely, travelling salesman, and set covering set integrates the two operability characteristics, has

packing, and set partitioning problems. These been developed. The proposed measure can be

algorithms have also been developed on various used to evaluate the probability of feasible

sequential and parallel computers such as the operation given uncertainties in process

CRAY YMP, the Alliant FX/8 and the CMU Nectar parameters and operational states. We have

network. recently developed an NLP optimization model for

optimizating the stochastic flexibility in nonlinear

2) Redesign of multicomponent separation process models. This formulation, which embeds

sequences. Our goal is an approach to redesign the integration of multiple integrals using Gaussian

separation processes where the species display quadrature, is solved with the Generalized

azeotropic behavior. These processes are Benders decomposition method. The application of

complex, requiring recycles in principle. Mixing this method has been illustrated in bi-criterion

can often be used to improve separation. For optimization problems for maximizing flexibility and

homogeneous azeotropic ternary mixtures, we minimizing investment cost. Also, an interesting

have two analysis results: (1) a technique to relationship of our metric with Taguchi's quadratic

determine all possible products which can be loss function has been established.

obtained in a single feed, two product distillation

columns whether at total or finite reflux and (2) an (5) Optimization-based Methods for Process

approach to determine if an extractive agent will Identification and Control. Optimization-based

allow separation of a binary mixture into desired algorithms are being developed for the control of

products. We are testing a new method to constrained, nonlinear processes; these are also

compute minimum flows in any column. We have being used to control open loop unstable

a methodology to produce automatically alternative processes. An extended Lyapunov-based stability

process configurations for such processes and theory has been developed and demonstrated. In

have tested it on a many examples, including a addition, both exterior and exact penalty function

mixture of methanol, water, n-pentane and strategies have been developed and analyzed for

acetone. We shall next study retrofit design for constrained model predictive control algorithms.

such processes involving trace species - i.e., for Finally, tailored nonlinear and quadratic

waste recovery systems. programming algorithms are being developed for

more efficient solution of these problems.

(3) Redesign of energy management systems.

Mixed-integer nonlinear programming (MINLP)

models have been developed for for grassroots Carnegie Mellon University and the redesign problems. The unique feature of Dept of Elec & Comp Eng $100860

these models is the fact that the level of energy Pittsburgh, PA 15213 03-C

recovery and selection of matches is optimized 92-3

simultaneously without fixing temperature Research on a Reconfigurable and Reliable

approaches. We have recently developed a new Manipulators

global optimization algorithm for networks with . Khosla T. Kanade

fixed toplogy. The basic idea relies on a rigorous

nonlinear convex NLP understimator that provides The goal of our research is to address the basic

tight lower bounds, and that is coupled with a theories of reconfigurable modular manipulator

spatial branch and bound method. Typically not systems that will culminate in the demonstration of

more than five NLP optimizations are required to these theories on experimental hardware. A

find the global optimum. Work is under way to modular manipulator system consists of a set of

extend method this for the optimization of link and joint modules of various sizes which may toplogies in which we intend to use as a basis a be assembled together in a desired kinematic

recent LP/NLP based branch and bound method configuration to achieve a specific task. The

for MINLP optimization. Finally, the interactive RMMS design emphasizes modular manipulator

Engineering Research 9 1992
components having consistent mechanical and been: development of a method for treating

electrical interfaces. The uniform interfaces will distributed systems with heat transfer by a

allow either semi-skilled field personnel or another generalization of distributed potential fields;

manipulator to rapidly configure a RMMS analysis of the optimal performance achievable

manipulator to meet specific task requirements. with heat-driven separation processes subject to

This basic research effort will address the problem realistic rate constraints; analysis of the efficiency

of mapping tasks into a manipulator configuration, of heat engines with distributed working fluid and

formulation of control algorithms for the mapped subject to constraints of nonzero rate;

configuration, and experimental verification of the determination of power and efficiency limits for

developed ideas. Though it is not the primary internal combustion engines with distributed

objective, we believe that building prototype working fluids. In addition, papers on minimization

experimental modules for demonstrating our ideas of entropy production under conditions of finite

will also contribute to the technology of modular rates of propagation of heat, and on a fully

manipulators. canonical formalism for thermodynamic evolution

of systems at nonzero rates were submitted after

For configuring a manipulator from task the Grant period.

requirements, we will develop methodologies that

map the task requirements into a specific

manipulator. The kinematic task requirements will University Of Chicago

be used to determine the link lengths and the The Enrico Fermi Institute $153,320

orientation of the modules. And the dynamic task Chicago, IL 60637 06-C

requirements will be translated to obtain the sizes 90-3

and ratings of the actuators or joints. The use of Fundamentals and Techniques of

both rule-based expert systems and optimization Nonimaging Optics

techniques will be investigated in obtaining a R. Winston

solution to this problem. For effectively controlling

modular manipulators (RMMS), a methodology for Nonimaging optics departs from the methods of

automatically configuring a controller will be traditional optical design to develop instead

developed using model-based and/or adaptive techniques for maximizing the collecting power of

control techniques. concentrating elements and systems. Designs

which exceed the concentration attainable with

focusing techniques by factors of four or more and

University Of Chicago approach the theoretical limit are possible. This is

Dept of Chemistry $92,747 accomplished by applying the concepts of

Chicago, IL 60637 06-C Hamiltonian optics, phase space conservation,

92-1 thermodynamic arguments, and radiative transfer

Finite-Time Thermodynamics and Effective methods. In the early nonimaging designs the

Energy Use mighty edifice of aberration theory was dismantled

R. Berry and replaced by a single key idea. According to

this, maximum concentration is achieved by

The broad goal of this project is the development ensuring that rays collected at the extreme angle

and application of methods to find the optimum for which the concentrator is designed are

performance of systems and processes amenable redirected, after at most one reflection, to form a

to thermodynamic analysis, and to find pathways caustic on the absorber. This principle proved

that yield optimal performance. The current project sufficiently elastic to accommodate most boundary

has the goals of: a) extending to distributed conditions in two dimensions (i.e., linear

systems the methods for treating lumped systems; geometry). Ideal solutions in three dimensions

b) finding how to select and use variables that have also been formulated. Our work on vector

describe nonequilibrium conditions, to study flux has led to a reexamination of the foundations

systems far from equilibrium; c) to find optimal of radiometry with emphasis on observable effects.

performance, using these methods, for systems Our theoretical work on nonimaging designs has

notable for high dissipation, such as separation led to demonstration of ultra-high flux from

processes. The results from the past year have sunlight which exceeds previous results by

Engineering Research 10 1992
substantial factors. Recent developments cause University Of Connecticut

the designs to be functionals of the acceptance Dept of Mechanical Engineering $50,000

angle. This permits new solutions which solve Storrs, CT 06268 01-A

classical problems in illumination for the first time. 92-3

Engineering Science Software Clarkson University Smithfield, RI 02917 $48,500 Dept of Chemical Engineering $62,000 01-A

Potsdam, NY 13676 01-C 88-3

e91-3 A Micromechanical Viscoplastic Utt and Drag Force on Droplets ols and Stress-Strain Model with Grain Boundary Particles In Wall-Bounded FlowsSliding

J. McLaughlln E. Jordan, K. Walker

The goal of this research is to obtain quantitative The first part of this project has focussed on

information about the lift and drag forces that act developing and experimentally verifying methods

on small droplets or particles that translate through of predicting the deformation response of

shear flows. Such forces affect the motion of polycrystalline metals from models of single crystal

droplets or particles near a rigid wall. Thus, to deformation, based on crystallographic slip. A

understand the deposition of droplets or particles crystallographic slip based single crystal

on the wall or their tendency to accumulate near viscoplastic model was developed and then used

the wall, a knowledge of such forces is important. in a mircomechanical model to predict the overall

viscoplastic response of the polycrystal. Single The approach used in the research involves a crystal experiments were used to get all model

combination of analytical, numerical, and constants from which polycrystalline response was

laboratory work. The analytical approach can predicted. Polycrystal experiments data was used

provide useful asymptotic expressions for the lift to critically test the predictions and the predictions

and drag forces in the regime of small Reynolds and experiments were found to be in good

numbers. In most situations of practical agreement.

importance, however, the droplet or particle

Reynolds numbers are not small compared to In the ongoing research, the goal is to try to

unity. As a result, direct numerical simulations of predict the degree of heterogeneity of deformation

the three-dimensional flow field around a sphere and verify these predictions experimentally. The

in a shear flow will provide the forces. In addition, existing self -consistent model is to be completed

experimental measurements of particle velocities by a second model based on periodicity which is

in a vertical homogeneous shear flow apparatus expected to be both more realistic and more

will provide additional information and permit computationally burdensome. The degree of

checks of the numerical study. heterogeneity of deformation will be studied by the

different experimental techniques. Neutron

The asymptotic analysis portion of the project is detraction experiments are planned in which

done. A computer code has been developed for defraction from a few grains at a time is studied to

the direct numerical simulations. The code determine lattice strains in individual grains. Many employs a hybrid spectral-finite volume technique grains will be surveyed to get statistical measure

to solve the incompressible Navier-Stokes of heterogeneity of grains including no surface

equation. The program has been used to compute grains. The Moire' strain analysis will also be

the lift force over the ranges of particle Reynolds done on large grained samples. The material

numbers of interest. Further work is needed to studied is the same one's used in the first phase,

determine the influence of the computational so that all the single crystal mechanical properties

domain size. However, the results obtained to date are accurately known. The data collected will

are in reasonable agreement with the predictions prove a unique complete set of data to test the

of the asymptotic theory. A homogeneous flow ability of the models in this program and other

apparatus has been constructed at Los Alamos models with respect to their ability to predict the

National Laboratory and is being tested at degree of heterogeneity of deformation.

Clarkson. Comparison of more data and the neutron

Engineering Research 11 1992
defraction data will also provide insight into the examples of autonomous systems that can exhibit

difference between surface grain behavior and chaotic behavior. Knowledge of the fluid-structure

interior grain behavior. Developing models that systems may provide some insights into the

realistically predict grain to grain heterogeneity and chaotic behavior of other energy system

verifying those models is a basic element in components.

modeling mechanical behavior. Heterogeneity is

particularly important to fatigue in which the most

unfavorably oriented grain is the site of failure. Cornell University

Sibley School of Mech & Aero Eng $105,818

Ithaca, NY 14853 01-C Cornell University 91-3

Mechanical & Aerospace Engineering $62,989 Experiments In Turbulent Mixing

Ithaca, NY 14853 01-A Z Warhaft

91-3

Chaos In Fluid-Structure Systems This project is concerned with experimental

F. Moon studies of scalar mixing in fully developed

turbulent flows, a subject relevant to our

Integrated theoretical and experimental studies are understanding of chemical reactions, combustion

being performed to enhance the understanding of and environmental pollution. Mixing in both

nonlinear oscillations and dynamic instability homogeneous and inhomogeneous turbulence,

phenomena involving both fluids and solid with and without the effects of buoyancy is being

structures and their coupling. The objectives are examined.

to contribute to the explanation of observed

phenomena, providing insights into chaotic The first experiment concerns scalar dispersion

characteristics of such coupled mechanical and mixing in a jet. This is studied using a novel

systems and ultimately, to the solution of method of introducing a scalar (temperature) into

engineering design problems. This is a joint an air jet by means of placing thin heated wire

project with Argonne National Lab. rings, axisymmetrically, downstream from the jet

origin. The diameter of the rings and their location

Fluidelastic instability of loosely supported tubes, from the jet is varied so that the effect of initial

vibrating in a tube support plate-inactive mode, is conditions on the subsequent evolution of the

suspected to be one of the main causes of tube scalar mixing can be studied. The placing of a

failure in some operating steam generators and thin wire ring in a jet is analogous to placing a line

heat exchangers. As a vehicle to understand the source in homogeneous turbulence, a subject that

nonlinear behavior of fluid-structure systems, has received much attention. We can anticipate

fluidelastic instability of loosely supported tube that the thermal field will be more complex than

rows in crossflow is being studied in detail. Tube that of a line source since as the flow evolves the

row with a motion-limiting stop configuration will thermal field from one side of the flow will begin to

be tested to investigate various response mix with that from the other side. This does not

characteristics and a mathematical model based occur with a line source in grid turbulence. So far

on the unsteady flow theory will be developed to as we can determine there has been no previous

predict the response characteristics of this study of a heated ring source in a jet. The effects

classical fluid-structure system. of two scalar mixing is also being studied by

adding a second ring. Preliminary findings show

Energy systems have had a history of dynamic unexpected results concerning the evolution of the

structural instabilities caused by fluid flow resulting segregation and cross-correlation coefficients.

in costly component repair and replacement and

loss of energy production. The understanding of The second main experiment is concerned with

dynamic characteristics, including periodic scalar mixing in stably stratified decaying grid

oscillations, random vibration, and chaotic motion, generated turbulence. A temperature (density)

will impact the design and reliability of these gradient is formed at the entrance to the plenum

systems in both the near and long term. In chamber of the wind tunnel and then the flow is

addition, fluid-structure systems are classical passed through a turbulence generating grid.

Engineering Research 12 . 1992
Single and multiple line source dispersion and also particulate addition from above, into a

experiments on mixing across sharp temperature liquid bath consisting of two immiscible layers of

steps, with and without buoyancy, are being liquids having roughly the same viscosities as slag

attempted. and matte or metal and with roughly comparable

density ratios.

Dartmouth College

Thayer School of Engineering $135,000 Dartmouth College

Hanover, NH 03755 06-C Thayer School of Engineering $120,599

91-2 Hanover, NH 03755 01-C

Mixing and Settling In Continuous Metal 92-3

Production Two Phase Potential Flow

H. Richter G. Wallis

For reasons of both energy conservation and The objective is to develop theorems for twoenvironmental protection, tonnage oxygen has phase potential flow analogous to those existing

become an essential component in many ferrous for single phase flow.

and nonferrous smelting and refining operations.

Innovative reactors such as the QSL converter for Using one function, the "exertia," which describes

direct lead bullion production are also suitable for the external fluid inertia due to relative motion of

direct coppermaking and a modification of the suspended particles, it has been possible to derive

reactor is also very attractive for steelmaking. the average stress tensor, kinetic energy, overall

momentum flux tensor and equations of motion for

Oxygen and fuel are bottom-injected into the uniform systems of particles and the effective

molten bath of these essentially horizontal reactors Bernoulli equation for the fluid flowing through a

in controlled rates required for heating, physical stationary array of particles.

mixing and chemical reaction purposes. Sufficient

turbulence is generated to maximize heat and Recent developments include more general

mass transfer rates. However, such bath descriptions of the mean particle stresses and the

turbulence is opposite to the process requirement averaged Bernoulli equation for the fluid when

for continuous countercurrent flow of liquids at both phases have a general motion. Links have

specific temperature, compositional and oxygen also been established between this approach and

potential gradients. The powerful stirring effected Guerst's variational methods including the

by submerged gas injection is therefore judiciously derivation of equations of motion for each phase,

localized so as to provide adequately calm settling it being possible for the dispersed phase to be

zones between the active turbulence zones in a compressible.

staged mixer-settler.

The equations of motion for each phase have also

The research objectives of the work are to learn been expressed in terms of a mutual "interfacial

about the behavior of gas and particulate matter in pressure tensor" that is related to both the average

turbulent liquids, the nature and paths of liquids stress in the dispersed phase and the net force on

and particulate entrainment into the plumes, and the continuous phase. This interfacial pressure

separation phenomena including travel to and tensor is also closely coupled to the Reynolds

behavior in the settling zones. Such knowledge is stresses in the continuous phase.

of fundamental value in designing reactors for

continuous, direct metalmaking. The exertia and added-mass coefficients have

been computed for various geometrical

The new information will predict bath mixing, heat arrangements of spheres, both in an infinite array

and mass transfer and settling parameters under and in tubes. Comparable measurements were

the variety of operating conditions which will made by measuring the natural frequency of

prevail in continuous, direct metalmaking oxygen oscillation of such arrays in water. Future

reactors of the future. Therefore, it is proposed to experiments are planned in which more properties,

study gas injection through submerged injectors, such as pressure fluctuations, are measured.

Engineering Research 13 1992
Theoretical and experimental efforts are underway Idaho National Engineering Lab

to obtain realistic interphase forces including the Biotechnology and Geosclences $109,000

effects of viscosity and drag. Computations show Idaho Falls, ID 83415-2210 06-A

that the effects of pressure gradient, added mass, 89-3

phase change and drag do not add linearly except Three Phase System Modelling

at low Reynolds numbers. This has implications G. Andrews

for the transient response and stability of fluidized

beds. Many unit operations in environmental

engineering, including biological wastewater

treatment and flotation (used to remove colloids

Duke University from wastewater and sulfur from coal), involve

Mech Eng & Mat'ls Scl Dept $50,000 bubbles rising through water containing both

Durham, NC 27706 01-C surface-active materials and suspended particles.

90-3 There is no general theory to predict the

Analytical and Experimental Study of hydrodynamics near millimeter-sized bubbles in

Instabilities In Buoyancy-Driven Convection this situation, which makes it difficult to predict the

In Porous Media gas/liquid mass transfer rate (in biological

J. Georgiadis wastewater treatment) or the number of particles

that strike the bubble (in flotation). This task will

The mission of this research project is the study of develop a mathematical model of the situation on

thermal instability phenomena associated with the upper surface of the bubble where most mass

natural convection in two classes of fully-saturated transfer and particle capture occurs. The model

porous media systems: (1) porous media will be based on integral boundary layer theory for

saturated with pure fluids, and (2) porous media the hydrodynamics and the transport of surfactant

saturated with binary fluids. Our primary to and from the interface, and will include the

objectives are: (1) the delineation of the various effect of adsorbed surfactant on the force balance

stability domains for the convective flows and an at the bubble interface.

exploration of the convective states after the onset

of secondary instabilities, (2) the development of The results will be compared with experiments

novel experimental techniques for high precision designed to measure the particle capture rate as

measurements and determining the flow patterns a function of surfactant concentration (i.e.,

in porous media, and (3) the validation of interfacial tension) and particle concentration.

macroscopic governing equations for natural Particle capture rate is measured because it is a

convection in porous media. very sensitive indicator of bubble interface motion.

Emphasis is put on the first two objectives. An

experimental investigation of the onset of natural Idaho National Engineering Lab

convection in a porous medium with internal heat Applied Optics $493,000

generation is initiated. The potential of Magnetic Idaho Falls, ID 83415 06-A

Resonance Imaging (MRI) techniques in 90-3

visualizing low-speed flows in porous media is In-Flight Measurement of the Temperature of

also investigated. We will explore ways of Small, High Velocity Particles

obtaining quantitative information on interstitial J Flncke

velocity profiles by using a combination of spin

tagging and spatial encoding MRI processes. The measurement of temperature, velocity,

Direct numerical simulation and stability analysis of enthalpy, and species concentration in high

the pertinent convective states will be performed in temperature gases such as weakly ionized thermal

conjunction with the experimental component of plasmas has considerable importance in the areas

this investigation. of plasma thermal spray and the thermal plasma

Engineering Research 14 1992
synthesis of materials. In particular, the dynamics Multicomponent diffusion is calculated by a

of the plasma, the interaction of the plasma with self-consistent effective binary diffusion

its surroundings and the behavior of particles approximation, including ambipolar diffusion of

immersed in the plasma surrounding it are charged species. Subgrid-scale and k-epsilon

important in the understanding, development and turbulence models are included. Dissociation,

optimization of plasma process that involve fine ionization, and plasma chemistry are treated by

powders. means of general kinetic and equilibrium chemistry

routines. Discrete particles interacting with the

Traditional measurement techniques, such as plasma are represented by a stochastic particle

emission spectroscopy, have severe limitations model which allows for distributions in particle

and often yield excitation temperatures which sizes, shapes, temperatures, etc. Departures from

reflect neither the true gas kinetic temperature nor local thermodynamic equilibrium (LTE) are

the temperature of the electrons. Laser based accounted for by a two-temperature model which

measurement techniques which have been permits the electon and heavy-particle

developed and applied to the study of thermal temperatures to differ. Nonequilibrium populations

plasmas at this laboratory include Coherent Anti- of excited levels will be treated as separate

Stokes Raman Spectroscopy for species chemical species, with collisional and radiative

measurement, Rayleigh and coherent Thompson transitions between levels modeled as kinetic

scattering for heavy particle, electron temperature chemical rate processes. Applications of the

and number density measurement, laser scattering model to date include simulations of plasma jets

Doppler shift plasma velocity measurements, and and plasma spraying.

the simultaneous measurement of particle size,

velocity, temperature, and number density. In

addition to the laser techniques enthalpy probes Idaho National Engineering Lab

coupled to a mass spectrometer also provide Materials Technology Group $430,000

temperature, velocity and concentration Idaho Falls, ID 83415-2218 01-A

information. The experimental data produced is 90-3

used to benchmark the modeling work done under Elastic-Plastic Fracture Analysis Emphasis

a related program in "Modeling of Thermal Plasma on Surface Flaws

Processes" (see J. Ramshaw, Idaho National W Reuter, W. Lloyd, J. Epstein

Engineering Lab).

The objective is to improve design and analytical

techniques for predicting the integrity of flawed

Idaho National Engineering Lab structural components. The research is primarily

Energy & Systems Tech Grp $232,000 experimental, with analytical evaluation guiding the

Idaho Falls, ID 83415 06-A direction of experimental testing. Tests are being

90-3 conducted on a material (a modified ASTM A-710)

Modeling of Thermal Plasma Processes exhibiting a range of fracture toughness but

J. Ramshaw, C. Chang essentially constant yield and ultimate tensile

strength. As test temperature increases, the

Optimization of thermal plasma processing specimen configuration-fracture toughness

techniques requires a better understanding of the relationship complies initially with requirements for

space- and time-resolved flow and temperature linear elastic-fracture mechanics and extends

distributions in the plasma plume and of the beyond the range of a J-controlled field.

interactions between the plasma and injected Presently, compact tension and bend specimens

particles. The present research is directed toward are being used to develop state-of-the-art

the development of a comprehensive fracture mechanics data for comparisons with data

computational model capable of providing such developed from specimens containing surface

information. The model is embodied in the LAVA cracks.

computer code for two- or three-dimensional

transient or steady state thermal plasma These comparisons are presently underway for 6.4

simulations. The plasma is represented as a and 12.7 mm thick surface- flawed specimens.

multicomponent ideal gas governed by the Metallographic techniques are being used to

transient compressible Navier-Stokes equations. measure crack tip opening displacement and

Engineenng Research 15 1992
remaining ligament configurations for comparison substrate thermal interaction; understanding the

with analytical models. Other techniques including relationship of neural network structure and

microphotography and replicating of the crack tip associated learning algorithm to model

region to complement the above measurements development and learning dynamics in neural

are being used to identify limits and capabilities of networks with the objective of obtaining a

each technique. Moire interferometry techniques fundamental understanding of network transfer

are being used to evaluate and quantify the functions; and advanced sensing, including the

deformation in the crack region. These data are propagation and interaction of ultrasound in

being used to experimentally measure J and metallic solid and liquid media.

CTOD for standard (CT and SENB) specimens as

well as for specimens containing surface cracks. This project is part of a collaborative research

The above tests have been supplemented by program with the MIT.

using specimens fabricated from aluminum (dimple

rupture only) and titanium. The titanium

specimens are being used to study the fracture Idaho National Engineering Lab

behavior and the ability of existing models to Nondestructive Mat'ls Charac Group $200,000

predict failure for weldments. Moire interferometry Idaho Falls, ID 83415-2209 03-B

techniques are being used to study the local 90-3

constitutive behavior and the fracture process at Nondestructive Evaulation of

the crack tip region of the weldment. Automated Superconductors

techniques are being developed to obtain, store K Telschow

and analyze the moire data.

The purpose of this task is to perform fundamental This project is carried out in collaboration with research which will lead to the development and

Professors Parks and McClintock at MIT. application of new nondestructive evaluation

(NDE) techniques and devices for the

characterization of high-temperature

Idaho National Engineering Lab superconducting materials. In the near future,

Materials Technology Group $530,000 application of these new superconductors will

Idaho Falls, ID 83415 03-A require NDE methods for evaluating the properties

90-3 of wires, tapes, and coatings. Microstructural and,

Intelligent Control of Thermal Processes particularly, superconducting properties, must be

H. Smartt, J. Johnson measured noninvasively in a manner capable of

providing spatial information so that fabrication

This project addresses intelligent control of thermal processes can be optimized. Although the

processes as applied to materials processing. fabrication of these ceramic materials is being

Intelligent control is defined as the combined pursued by many different techniques at present,

application of process modeling, sensing, artificial there is enough similarity in the different

intelligence, and control theory to process control. superconducting materials and the fabricated

The intent of intelligent control is to produce a forms to begin research into NDE measurement

good product without relying on post-process techniques. A noncontacting AC induced current

inspection and statistical quality control measurement technique has been developed

procedures. The gas metal arc welding process is which can determine critical currents on a local

used as a model system; considerable scale with resolution down to 1 mm. This

fundamental information on the process has been technique can be used in conjunction with DC

developed at INEL and MIT during the past six transport currents to determine spatial variations in

years. Research is being conducted on an critical current dissipation. It also can be used

extension of the fundamental process physics, alone to induce the critical state and full field

application of neural network-like dynamic penetration into the sample directly under the

controllers and signal/image processors, and probe. With the aid of the "critical state" model for

development of noncontact sensing techniques. flux pinning, local critical current values can be

Tasks include physics of nonlinear aspects of determined without any connections to the sample.

molten metal droplet formation, transfer, and These measurements are being applied to coating

Engineering Hesearch 16 1992
and wire geometries and the results are being University Of Illinois

correlated with material microstructure information. ept Chemical Engineering $108,337

Nonlinear flux trapping signals are being recorded Urbana IL 61801 01-C

with a new pulsed probe extension of this 89-3

technique. Gas-Liquid Flow in Pipelines

T. Hanratty

University Of Illinois The long range goal of this research is to describe

Coordinated Science Laboratory $127,000 the macroscopic behavior of gas-liquid flow

Urbana, IL 61801 03-A systems by developing a phenomenological

91-3 understanding of small scale interphase

Model Building, Control and Optimization of interactions. The simplified systems of fully

Large Scale Systems developed flow in vertical and horizontal pipes are

T. Basar, P. Kokotovic being used. Specific goals are (1) to predict when

slugging will exist in horizontal flows, based on an

This program involves fundamental research on understanding of interfacial waves, (2) to develop

the modeling, control and optimization of large a model for slug flow in horizontal pipes, (3) to

scale systems. The main theme is model develop an understanding of vertical and

simplification for control and decision making. It horizontal annular flow by studying droplet

encompasses both linear and nonlinear models, entrainment and deposition and (4) to develop a

and deterministic and stochastic systems with basic understanding for the dispersion and

regular and/or singular perturbations. Research deposition of particles in a turbulent flow. Vertical

issues addressed are in modeling, optimization, experiments are conducted in pipelines with

stabilization and coordination, as well as in the diameters of 3/4 in., 1 1/2 in., and 2 1/4 in. The

development of computational schemes for horizontal flow facility has 1,2,3,4 in. pipelines

generating implementable control policies. Their mounted on a specially designed platform whose

common goal is to broaden the applicability of the angle can be controlled to within 0.01 degree.

concept of multimodeling as a systematic

approach to model simplification through Slugs have been observed to develop by a

decomposition/aggregation of linear and nonlinear nonlinear Kelvin-Helmholtz mechanism at

large scale systems. superficial gas velocities less than 3 m/s. Gravity

waves formed at the entry grow and double their

Current research is concentrated on the design of wavelength. These waves can tumble or grow to

robust controllers for linear and nonlinear systems a height such that they are unstable, depending on

under various types of uncertainty which appear the liquid height. At gas velocities greater than 3

as unknown parameters, external (time-varying) m/s, the process is enhanced by coalescence of

disturbances, or nonlinearities whose functional waves.

forms are not exactly known. We study linear

systems which exhibit time-scale separation in Detailed temporal variations of pressure profiles

open-loop dynamics (such as singularly perturbed have been made during the passage of slugs.

models), which are subjected to unknown external These have been used to develop a hydrodynamic

disturbances of finite energy. Here the robustness model.

is with respect to these external disturbances and

the unknown singular perturbation parameter, and Studies of droplet deposition in vertical annular

the criterion is minimization of a worst-case flows have revealed the surprising result that

performance. We also study nonlinear systems deposition rates are independent of droplet

where the uncertainties are either parametric or concentration at large enough concentrations.

structural, with the criterion being one of stability. Photographic studies of drop size and drop

Engineering Research 17 1992
configurations are being used to obtain an Jet Propulsion Laboratory understanding of this phenomenon. Pasadena, CA 91109 $109,200

03-C Particle dispersion and deposition in turbulent Neural Learning Formalisms for Global 89-3

flows are not easily described by classical Eulerian Manipulator Redundancy Resolution

methods. Therefore, Lagrangian methods are Problems in Unstructured Environments

being explored whereby the concentration profiles J, Barhen

and deposition rates are described as resulting

from a distribution of point or line sources. These In many applications the robotic arm needs to

techniques have been used to study vertical have sufficient maneuverability so as to carry out

annular flow, horizontal annular flow and sediment its tasks in the presence of obstacles and in

transport. constricted locations. One way to achieve that is

to endow the arm with an extra degree of freedom.

University Of Illinois At Chicago While mechanically that is easy to implement, say

Energy Resources Center $73,391 by the addition of an extra joint, the mathematical

Chicago, IL 60680 01-B problem associated with the guidance of the arm

91-2 becomes very difficult. The reason for that is that

Momentum and Heat Transfer Processes in with the conventional six-degree-of-freedom

Viscoelastic Fluids system the relationship between the location and

J. Hartnett orientation of the arm's joints and the location of

the arm's tip is uniquely determined, while the

Recent studies of the heat transfer performance of redundancy accompanying additional degrees of

viscoelastic aqueous polymer solutions have been freedom yields an infinity of such relationships.

directed to the pool boiling behavior of such The proposed research willaddress the resolution

solutions. The heat transfer coefficients of of the mathematical problems arising in the latter

aqueous hydroxyethy cellulos (Natrosol) solution case.

boiling on horizontal wires were found to be

considerably higher than the values found for Specifically, neural networks will be used to permit

water alone, whereas the pool boiling performance the robot arm to learn which of the possible

of other polymer solutions (including motions of the arm are the most appropriate under

polyacrylamide solutions) was inferior to that of given conditions. These networks are really

water. A distinguishing characteristic of the models of the way we think, learn, and remember.

Natrosol solutions is their lower surface tension Those functions are represented by a set of

values. Accordingly an investigation of the differential equations with many possible solutions,

influence of two different surfactants (i.e. agents each of which is accessible from well defined initial

which reduce surface tension) on the pool boiling conditions. In effect the individual solutions serve

behavior of aqueous polyacrylide solutions was to encode a learned response to a given stimulus.

carried out. When the surfactant polyoxyethylene

sorbitan monooleate (Tween 80) was added to the

aqueous polyacrylamide solution the surface Johns Hopkins University

tension decreased by 10 to 20% but the boiling Mechanical Engineering Dept $149,980

performance was not affected. In contrast, the Baltimore, MD 21218 01-C

presence of sodium lauryl sulfate (SLS) resulted in 92-3

a similar decrease in surface tension but a Numerical and Physical Modeling of Twosignificant increase in the boiling heat transfer Phase Flow Phenomena at Large Reynolds

coefficient was recorded relative to the pool boiling Numbers

performance of deionized water. On the basis of A rosere

these experimental results it can be concluded that

lowering the surface tension of an aqueous The ultimate purpose of this study is to put the

polymer solution does not guarantee enhancement widely used engineering averaged-equations

of the boiling heat transfer performance. models of multi-phase flows on a firmer basis by

Engineering Hesearch 18 1992
comparing their results with those of direct to Navier Stokes turbulence and these are being

numerical simulations. actively pursued. In collaboration with workers at

Los Alamos National Laboratory, we are also

Viscous effects on slip-free spheres (a useful carrying out related turbulence computer

approximation for gas bubbles) have been studied simulations with a resolution not previously

computationally to determine the validity of the attainable.

Lagrangian method often used in the derivation of

the equations for such systems.

Lawrence Berkeley Laboratory A new approach to phase averaging has resulted Accelerator & Fusion Res Div $132,000

in a rather unexpected form of disperse-flow University of California 06-C

equations in the dilute limit. The properties of the Berkeley, CA 94720 90-3

equations and the advantages and limitations of

this new approach are being investigated. Studies in Nonlinear Dynamics

A. Kaufman, R. Uttlejohn A study has been carried out of the accuracy of

the singularity method for the direct numerical This project involves studies of fundamental

simulation of the potential flow motion of many properties of nonlinear dynamical systems which

particles in a liquid. arise in physical situations of importance to energy

research. A major area of theoretical investigation Current efforts center on the simulation of flows in concerns several different aspects of wave

which the compressibility of the particles (bubbles) systems. Special focus is given to wave packets;

plays an important role. the role played by the Maslov index in

multidimensional wave problems; the occurrence

of Berry's phase in wave and other dynamical

Robert H. Kraichnan, Inc. systems; the role of periodic orbits in the spectrum

303 Potrillo Drive $64,303 of chaotic wave systems; and linear mode

Los Alamos, NM 87544 01-C conversion. Recent progress includes the

90-3 exploration of the relation between the Maslov

Tuibulence Theory and Reduced index and the phase space structures of nonlinear

Hydrodynamic Description Hamiltonian dynamical systems; new methods of

R. Kraichnan computing the Maslov index, both for finding wave

functions and eigenvalues; elucidation of the

Turbulent flow is omnipresent in geophysics and in relationship between the Bohr-Sommerfeld and

energy-producing devices. Atmospheric turbulent Maslov phases and the recently discovered

transport plays an essential role in the movement "Berry's phase"; a discovery of Berry's phase in

of heat, moisture. and pollutants. Turbulent flows the adiabatic motion of charged particles in

typically contain an enormous amount of informa- magnetic fields; a study of complex rays in eikonal

tion. Both for practicable computation and for theory, and their relation to complex Lagrangian

physical understanding, it is necessary to extract manifolds, Stokes' lines and turning points; a

essential information in compact form. This numerical exploration of the role of periodic orbits

project explores novel approaches to economical in the spectrum of a chaotic wave system; and the

and meaningful description of turbulence. first treatment of mode conversion phenomena for

Concentration in the past year has been on a multidimensional systems, involving novel

method of modeling turbulence by nonlinear "reduction" techniques. Emphasis is given to the

distortion (mapping) of fields with simple, known use of a phase space approach to wave

statistics. This method has been very successful phenomena in all these applications. A second

for Burgers model of turbulence and is being area of investigation concerns action principles,

applied to chemical reaction problems by an which are being used to imbed single-particle Lie

increasing number of researchers in the chemical transform perturbation methods in collective

engineering community. New developments in the models, such as Vlasov-Maxwell systems.

method now enable easily computable applications Nonlinear phenomena (e.g., ponderomotive forces)

are thus dealt with systematically.

Engineering Research 19 1992
Lovelace Medical Foundation found that uses a robust statistically based

Bioengineering Research $52,686 calculation to determine the camera motion and

Albuquerque, NM 87108 01-C feature points in one image that correspond to

91-2 given features in the other image (stereo

Two-Phase Flow Measurements by NMR correspondence). This method is presently being

E. Fukushlma, S. Altobell, A. Caprihan evaluated experimentally. Preliminary results from

tests with synthetic images show that the method

This project will develop nuclear magnetic produces accurate results when there are not too

resonance (NMR) methods to measure velocity many points without stereo matches in the two

and concentration distributions of both phases in images, when all the points in the left and right

two-phase flows. Systems to be studied include images belong to objects with the same threeconcentrated suspension flows in circular tubes, dimensional motion relative to the cameras, when

solid-liquid flows in Couette geometries, gas- th e no ise l ev els are less than about 10%, and

liquid, and liquid-liquid i C flows g g when the cameras are accurately mounted in a

parallel configuration. Techniques are currently

One approach to velocity measurements is to being developed to extend the method to

measure an incremental spatial displacement of situations where the four conditions mentioned

nuclear spins that are non-invasively tagged above are not met.

whereas another is to measure the phase

evolution of the spin precession which depends on

the translational velocity. The first method is best University Of Maryland

suited for flows in uniform geometries such as pipe Dept of Electrical Engineering $86,033

flows whereas the second, more complex method, College Park, MD 20742 06-C

is better suited for non-uniform cases such as for 92-3

non-neutrally buoyant flows in a Couette Mathematical Models of Hysteresis

geometry. I. Mayergoyz

Several steady flow studies such as concentrated This research is concerned with the development

suspensions in pipes and Couette have been of mathematical models of hysteresis. These

performed, to date. In order to move on to models are phenomenological in nature and, for

nonsteady flows, faster velocity imaging this reason, they can be applied to the description

techniques need to be developed and a new of hysteresis regardless of its physical origin.

commercial shielded gradient coil is in its extended

installation stage right now (in June, 1992). The main research objectives of the ongoing

Preliminary images of bubbles rising in a fluid look research can be briefly summarized as follows:

promising and further attempts to image gas-liquid further development of scalar and vector Preisach

flow systems will be made. type models of hysteresis (superposition models,

two-input models for magnetostrictive and

piezoelectric hysteresis and their tensor

University Of Maryland extensions, feedback Preisach-type models),

Dept of Mechanical Engineering $55,473 development of Preisach-type models for viscosity

College Park, MD 20742 03-C (aftereffect), application of Preisach-type models

90-3 to the description of superconducting hysteresis

The Use of Stereo Optical Flow Fields In the and evaluation of hysteretic losses in hard

Determination of 3-D Motion and Stereo superconductors, software implementation of the

Correspondence Preisach hysteresis models, extensive

J. Duncan experimental testing and verification of hysteresis models, investigation of penetration of

In this study, the optical flow fields in the left and electromagnetic fields into nonlinear hysteretic

right image sequences of a stereo camera pair are media. It is hoped that, as a result of this

being used to determine the three-dimensional research, the Preisach-type models of hysteresis

motion and position of the camera platform relative will emerge as a useful and indispensable tool in

to objects in the field of view. A method has been engineering research and design problems.

Engineering Research 20 1992
University Of Maryland University Of Maryland

Electrical Engineering Department $83,537 Dept of Mechanical Engineering $75,000

Baltimore, MD 21228 03-B & Systems Research Center 03-C

92-3 College Park, MD 20742 92-3

Pulse Propagation in Inhomogeneous Optical

Waveguides The Mechanics of Redundantly Driven

C. Menyuk Robotic Systems

L Tsai

Our research, which was originally focused on light

propagation in inhomogeneous optical fibers, has The objective of this research is to gain better

broadened in scope to include studies of solid understanding of the kinematics, dynamics and

state rib waveguides and Y-junctions which are control laws associated with manipulators having

used to guide and switch light. The work on redundant actuators but no redundant degrees of

optical fibers is divided into two research projects. freedom. The major advantages of a redundantly

driven manipulator are zero backlash, better

The first project concerns long-distance repeatability, and fail-safe.

communication using solitons. We have been

particularly concerned with the effects of randomly Force transmission characteristics associated with

varying birefringence, and we have shown that its tendondriven manipulators have been investigated.

effect is benign. From the basic equations, we It is shown that the effect of tendon routing can be

were able to show from an appropriate ordering characterized by a condition number and by the

expansion that the nonlinear Schrodinger equation direction of its homogeneous solution. It is also

is the lowest order equation, and, hence, we shown that isotropic transmission can be achieved

expect its behavior to dominate the soliton for certain types of tendon routing. To resolve the

evolution even in a highly birefringent fiber, as redundancy in tendon forces, an efficient algorithm

long as the birefringence is rapidly varying. We is being developed. It is hoped that this algorithm

have also studied optical fiber soliton switches will make realtime, computed-torque control

based on trapping and dragging. To do the work feasible.

on optical fibers, we have collaborated with

scientists at AT&T Bell Laboratories. The first Gear backlash introduces discontinuity, positioning

solid state project was to find the effect of a uncertainty, and impact in mechanical systems.

quantum well on the propagation characteristics of To overcome these difficulties, an innovative

a rib waveguide. Using a planar guide as concept utilizing unidirectional redundant drives to

reference, we were able to show that the effect of ensure positive coupling of gear meshes has been

the real geometry is qualitatively small but can conceived. Atwo-DOF prototype manipulator has

have a significant quantitative effect. The second been designed and tested. The experimental

solid-state project is to determine the effect of results indicate that use of unidirectional redundant

dry-etching on the mode-holding characteristics of drives improves the repeatability by an order of

the device. As a consequence of the etching, the magnitude.

height at which the junction splits can vary. We

showed that the rounding has a very small effect, A two-DOF wrist mechanism is also being

in contrast to blunting which occurs when the investigated. Two types of mechanical

materials are chemically wet etched. transmission arrangements are considered. The

first uses gear trains in all three transmission lines

while the second uses gear trains as well as

tendons. The purpose is to demonstrate that

precise control can be achieved via mixed rigid

and flexible transmission elements. A computer

simulation model including compliance and

backlash as fundamental concern will be

developed.

Engineering Research 21 1992
University Of Maryland University Of Massachusetts

Dept of Mechanical Engineering $132,000 Chemical Engineering Department $121,000

College Park, MD 20742 01-C Goessmann Laboratory 03-A

91-3 Amherst, MA 01003-0011 90-3

Lagranglan Analysis of Contaminant

Dispersal in Bounded Turbulent Shear Flows A General Procedure for the Synthesis of

J. Wallace, P. Bernard, J. Balint Process Flowsheets

J. Douglas, M. Malone

The objective of this project is to study the

physical processes associated with turbulent This research is focused on developing a more

scalar transport in shear flows with a view towards general procedure for the systematic synthesis of

developing novel techniques for predicting flowsheets for chemical processes. These

containment dispersal in the environment. A procedures are intended to identify the most

closely coordinated experimental and theoretical important process alternatives, the dominant

research program is followed combining wind design variables, and the minimum energy

tunnel experiments using hot- and cold-wire consumption for each alternative in processes

probes, smoke visualizations and image containing vapor, liquid-liquid and/or solid phases.

processing, with numerical simulations. This work will substantially expand process

Temperature and concentration contours of point synthesis capabilities, building on earlier results

and line source diffusion in the boundary layer which were the basis of a hierarchical synthesis

obtained from visualization data and from a procedure for continuous processes containing

numerical simulation of channel flow are being mixed vapor/liquid phases.

compared in order to verify the accuracy of the

two techniques. A Lagrangian decomposition of A hierarchy of decisions and rules for the

the scalar transport correlation into fundamental synthesis of liquid-liquid separation systems and

physical processes is being carried out using for crystallizer, filter dryer steps have been

ensembles of particle paths computed in the developed. The generalized flowsheet structure

simulation of turbulent channel flow. This provides has also been identified and an evaluation of the

insight into the physical mechanisms underlying interactions with other separation steps is being

transport and how they may be modeled. studied. One important difference between

vapor/liquid processes and solids processes arises

300 images from the boundary layer flow on account of the optimum operating temperature

visualization, at Re~1070, of the lin- source of for decanters, dissolvers, and crystallizers. The

smoke have been digitized and analyzed. It has popular energy integration procedures, which have

been determined that there is a strong correlation led to major energy savings in continuous

between the momentum and mass fluxes. In processes over the last decade, must be modified

addition, temperature measurements have been to include this unknown temperature.

carried out for comparison to the numerical

simulation. Turbulent plumes emanating from line Noncontinuous processes which include one or

sources have been computed using a direct more important batch processing steps are also

numerical simulation of channel flows. The mean being studied. An algorithmic approach based on

scalar field and higher order statistics have been simulated annealing for the scheduling of batch

compared with the physical experiments as well as processes including due date and inventory

a series of computations we have performed using considerations has been developed and the

turbulent closures and random flight models. interactions of the design with the production

schedule are under study.

Engineering Research 22 1992
University Of Massachusetts- methods that can be used to automate the

Lowell -gas-metal arc process.

Department of Electrical Engineering $79995 Previous research on this project mapped the light

Lowell, MA 01854 01-C emissions from a welding arc spatially, temporally,

91-3 and spectrally. This work identified windows

Stability and- Heat Transfer In Time- where it is best to photograph or otherwise view

Modulated Flows the weld pool. Later work developed an

C. Thompson understanding of the forces controlling metal

transfer in gas-metal arc welding. Welds were

This project represents an analytical/experimental made with steel, titanium, and aluminum using a

effort directed toward understanding the processes variety of shielding gases and varying the welding

responsible for the generation of boundary layer current to achieve different metal transfer modes.

instabilities in time-modulated flows. In particular This work was done using a laser back-lighting

the temporal modulations of the basic state by technique developed at MIT which allows one to

harmonic and free-stream vorticity is considered. estimate the anode spot attachment on the

The objectives of this work are to: 1) Develop melding electrode. These experiments have led to

analytical models describing instability in new hypothesis to explain the transition from

temporally modulated flows. The dynamics of the globular to spray metal transfer. A mathematical

system is examined using stability analysis and model was based on this model which accounts

validated against experimental observations. for the forces due to gravity, surface tension,

2) Determine the growth and propagation of electromagnetic, and plasma jet drag. By studying

unstable disturbances occurring in the viscous the relative importance of each of these forces, it

region. The influence of the modulation amplitude was shown that 10 to 20 percent higher weld

and wall features such as wall curvature are deposition rates could be achieved with pulsed

considered. 3) Examine the stabilizing influence of current welding using different shielding gases.

steady-flow. 4) Examine global and local

instability resulting from modulation of the free- The research during the current year has reviewed

stream near points of mean-flow stagnation.methods of filtering the voltage and current

5) Categorize results suggestive of possible waveforms during pulsed current welding in order

mechanisms for heat transfer. to extract signals which can be used to control the

process. A new process control system has been

Models for the transition to chaotic fluid motion in developed and integrated with the welding developed and integrated with the welding time modulation flow have been developed. It has equipment. Work has begun to study methods of

been shown that oscillatory modulation of the mechanically controlling droplet detachment from

basic flow results in successive period-doubling the welding electrode.

bifurcations of three-dimensional vortical

disturbances. Above an amplitude threshold these

disturbances exhibit temporally chaotic behavior. Massachusetts Institute Of

Massachusetts Institute OfTechnology

~Technol~~o~~gy Energy Laboratory $105,000 echnology Cambridge, MA 02139 03-A

The Energy Laboratory $122,300 91-3

Cambridge, MA 02139 03-B Synthesis and Optimization of Integrated

91-3 Chemical Processes

Metal Transfer in Gas Metal Arc Welding L Evans

T. Eagar, J. Lang

The objective of this research is to investigate and

The present research is part of a cooperative develop improved systematic methods for the

program among faculty at MIT and staff at the synthesis and optimization of chemical processes.

Idaho National Engineering Laboratory (INEL) to The work to date has focused primarily on

develop a sound understanding of the arc welding synthesis of heat and work integration systems for

process and to develop sensing and control

Engineering Research 23 1992
large-scale continuous chemical plants. In the Massachusetts Institute Of

past year we have redirected the project to T holo

address methods for synthesis and optimization ofno gy

batch and semi-continuous processes. Lab for Manufacturing & Product $158,000

Cambridge, MA 02139 03-B

The synthesis of heat and work integration 91-3

systems in process plant is important in the design Multivarable Control Of The Gas-Metal Arc

of new plants and in the retrofitting of existing Welding Process

plants for energy conversion. A typical process D. Hardt

plant, such as a petroleum refinery, a

petrochemical plant, or a paper mill, requires The Gas-Metal Arc Welding Process (GMAW) is

energy in the form of heat to raise the temperature a highly productive means for joining metals and

of process streams and in the form of work to is being used increasingly for structures and

drive pumps and compressors and meet other pressure vessels. It presents a challenging

mechanical energy needs. The goal of heat and multivariable control problem entailing both

work integration is to reduce this external energy geometric and thermal outputs. These outputs all

requirement through better process integration combine to determine the strength and toughness

For example, the heating requirement can be of the resulting joint. The overall objective of this

reduced by allowing hot streams that must be work is to examine the problem of simultaneous

cooled to exchange heat with cold streams that regulation of all real-time attributes of a weld.

must be heated. Also, the process itself can be Past work has established the viability of

used to generate mechanical energy by independent control of thermal characteristics and

introducing heat engines. the present work is examining the geometric

aspects of weld pool control.

This research has focused on developing

computer-based methods to help engineers One objective of this work is to develop basic

synthesize a process with improved energy process modeling and control schemes to allow

integration. The strategy has been to combine independent regulation of the weld bead width and

modern mathematical programming techniques, height A control model relating wirefeed and

sophisticated rigorous models of the process travel speed to width and height was developed

utilities system and heat recovery network, and using transfer function identification techniques

heuristic methods to develop an overall applied to a series of step welding tests. The

methodology that is more powerful than traditional resulting discrete transfer function was found to be

approaches. Methods and computer programming nonlinear in both the static and dynamic parts

techniques of artificial intelligence have been used owing to a strong dependence upon the input

where appropriate. An effort was made to magnitudes. This model was then used to

overcome the idealizations characteristic of much develop a decoupling controller design that

previous process synthesis research to develop cancels the nonlinear behavior using gain

methods that will help engineers solve realistic scheduling. Proper regulation of the process was

industrial problems. The net result of the research demonstrated, but the limited range of control

has been an improved understanding of the nature afforded by this process and the significant

of the problem of energy integration in process process delays that were in evidence led to very

plants. poor disturbance rejection. It is apparent that the

GMAW process will need significant modifications

With the completion of three doctoral theses on to overcome these problems.

the project in the area of heat and work

integration, the research is now being redirected to In an attempt to merge previous results on the

address the synthesis and optimization needs of regulation of thermal characteristics in real-time

batch and semi-continuous manufacturing with the geometry control work, we are developing

processes. These processes are of increasing a control system to independently regulate the

importance for the manufacture of high-value weld bead width and the width of the heat affected

performance products such as those produced by zone. Initial work is concentrating on simulation of

biotechnology. Yet, the development of systematic wide seam welding using an analytical heat

computer-based methodologies for batch process transfer model as well as a finite difference

is only in its infancy, process model. A key issue in the problem is the

Engineering Research 24 1992
strong coupling between the inputs (current and design of cryogenic devices, including heliumtravel speed) and the outputs. The use of high temperature (4.2 K) as well as high-Tc

frequency transverse motion of the torch is being superconducting magnets.

investigated as a means of overcoming this

coupling. Once the control latitude is increased, a

two variable control scheme based on both video Massachusetts Institute Of

and infra-red sensing will be implemented. Technology

Finally the depth of penetration of a weld is the Dept of Mechanical Engineering $196,000

most important indicator of weld strength, yet it is Cambridge, MA 02139 01-A

the one variable that is essentially impossible to 91-3

measure directly. A real-time depth estimator has Modeling and Analysis of Surface Cracks

been developed based on solution of an inverse D. Parks, F. McCllntock

heat transfer problem. Surface temperature

measurements are used as inputs to the analytical This research focuses on the analysis of ductile

model, which then tunes the unknown parameters crack initiation, growth and instability in

until predicted temperatures match the measured. part-through surface-cracked plates and shells.

Initial experiments with this model, using surface The overall approach consists of careful

temperature measurements from the top and calculations of crack front stress and deformation

bottom of the weld, have shown accurate and fields, and correlation of cracking with

rapid convergence and development of a depth experimental observations being conducted at the

control system based on this estimator is now Idaho National Engineering Laboratory.

being processed. Recently, significant progress has been achieved

This project is a collaborative program with INEL. in developing and applying a two-parameter description of crack front fields. The amplitude of

crack tip deformation is characterized by J or

Massachusetts Institute Of C TOD, while the hydrostatic constraint in the

near-tip region correlates well with a parameter

Technology related to the so-called T-stress, or second

Dept of Mechanical Engineering $88,020 elastic Williams' eigenfunction.

Cambridge, MA 02139 01-D

91-2 Simplified engineering applications of surface

Cryotribology: Development of crack analysis are being developed in the context

Cryotribological Theories and Application to of the line-spring model. Specific enhancements

Cryogenic Devices include improved elastic-plastic procedures for the

Y. Iwasa practically important case of shallow surface

cracks, as well as simple methods for calculating

The principal objective of this cryotribology (low- the T-stress along surface cracks fronts.

temperature friction and wear) project is to

contribute towards the advancement of cryogenic Detailed elastic-plastic stress analyses of cracked

systems by examining the basic mechanisms of structural geometries provide a basis for

cryotribology. Because relative motion is essential interpreting experimental observations, for

to the operation of many cryogenic devices, an quantitatively assessing inherent limitations of

improved understanding of cryotribology will place nonlinear fracture mechanics methodology, and for

us in a much better position to meet the future extending these boundaries through development

demands that will be required of these low- of two-parameter characterization of crack tip

temperature system. While continuing to generate fields. Simplified but accurate analytical methods

more cryotribological data, we have also been are also under development for analysis of

expanding our efforts to emphasize the surface-cracked plates and shells. Emphasis is

development of cryotribological theories which will placed on better understanding complex

enable a more systematic approach towards the three-dimensional features of elastic-plastic crack

tip fields.

Engineering Research 25 1992
Massachusetts Institute Of distribution within beds and of failure of individual

Technrology particles within such beds. Simulations correlated T~ecn~h~no~l~ogy^ well (qualitatively) with experimental crushing The Energy Laboratory $133,000 within beds of spherical glass particles. It was

Cambridge, MA 02139 01-A determined that, for brittle materials, particle failure

91-3 was adequately predicted by a size-dependent Basic Engineering Sciences of Solids critical value of the maximum single load on the

Comminution sphere, regardless of the magnitude and number

C. Peterson of lesser loads. Failure of plastic materials,

however, is inhibited by the presence of significant This work is a study of the energy and force secondary loads.

requirements for fine grinding of minerals and coal.

Fine grinding is a low-efficiency process at best, A "bed efficiency" was defined as the energy

and it can become excessively energy intensive as necessary to fracture an individual sphere between

finer grinding is required for better cleaning of coal flat plates to that necessary to fracture a similar

or for beneficiation of lower grade ores. sphere subjected to multiple loading within a

particle bed. As expected, the value of this

Research is directed to the crushing behavior of efficiency falls rapidly from a value of one (by

individual particles, of particles within particle beds definition) for a bed of one particle depth to lower

subjected to compressive loading, and to the values as bed depth increases, and energy is

transport of materials into and through the wasted on frictional motion within the bed.

comminution device, with particular attention to the However, for bed depths above about 5 particle

separation and transport of fine particles from the diameters, the bed efficiency seems to level off at

active crushing zone. about 40%. This is of significance since all

particle beds (i.e., beds treating through flow rates Although the program conducts basic research, a of interest) will be of depths much greater than five

machine has been conceived to provide focus for particle diameters. Bed efficiency is also a

the various aspects of the research. It was known function of the extent to which the bed is

from the outset that both crushing behavior within compressed. Since initial bed loading results in

bed movement and compaction, with energy the bed and material transport through the device consumed in friction but with little or no fracturing,

were critical to the achievement of high efficiency. initial bed efficiency is zero. As compaction

It is essential to remove fine material from the bed continues and fracturing begins, bed efficiency

as it is formed if the remaining coarse material is rises and peaks at about 40% for a compaction to

to be efficiently fractured. The machine concept, about 80% of initial bed height. Thereafter, while

therefore, combines the crushing action of a jaw further compaction continues to break particles,

crusher with upward transport of granular material, the necessary force rises rapidly and, hence, the

driven by an upward fluid flow, the mixture being work input increases disproportionately. This

in a fluidized or near fluidized state. Since fine sudden rise of required force correlates with filling

particles are more easily fluidized than coarse, it the voids between coarse particles with the fine

was argued that fluidized transport would fragments of the crushed particles. Peak bed

preferentially transport fine material, leaving efficiency is about 40%--that is, it takes at least

coarse material behind for further crushing action. two and one-half times as much energy to crush

Preliminary experiments have shown that such a particle within a bed as it would take if the

size-dependent segregation and transport is particle could be crushed individually between flat

indeed achieved, but research continues to plates. At the peak efficiency compaction, about

establish an understanding sufficient for design. 40% of the initial coarse material has been

fractured within the bed.

Early work concentrated on crushing behavior,

both of individual spheres (between flat plates and With this understanding of crushing action within

subjected to multiple side loads in addition to beds, the focus has shifted to studies of fluidized

loading from the plates), and of particle failure bed behavior and the relative motion of particles of

within particle beds. Computer simulation of 2- different sizes within the bed. Preliminary work

dimensional beds composed of 3-dimensional with mixtures of 2 and .8 mm glass spheres

spheres provided a good picture of load

Engineering Research 26 1992
demonstrated segregation will be rapid enough for electrochemistry, and the particle shape and size

practical devices. More sophisticated research is distribution is also being obtained.

now underway to provide quantitative data on

particle velocities and to explore a wide range of

flow conditions and geometries. Much finer Massachusetts Inst Of Tech

particles, typical of those observed upon crushing Dept of Chemical Engineering $63,000

of brittle coarse particles, are being used, which Cambridge, MA 02139 06-C

should enhance the segregation behavior. 91-3

Los Alamos National Lab2

Massachusetts Massachusetts Institute Of Design Engineering Division $108,000 Institute Of Los Alamos,fNM 7545 06-C Alamos, NM 87545 06-C Technology 91-3

Dept of Mechanical Engineering $116,76 Sandia National Laboratories

Cambridge, Cambridge, MA MA 02139 01-C 01-C Fluid & Thermal Sciences Dept $198,000 92-3 Albuquerque, NM 87185 06-C

Rheological and Flow Characteristics of 91-3

Dense Multiphase Slurries Employing a Macrostatistical Hydrodynamics

Bimodal Model H. Brenner?, A. Graham2, L Mondy' R. Probstein

This research aims to correlate the macroscopic The efficient utilization, transport, and handling of rheological behavior of suspensions with their

dense multiphase slurries containing high volume statistical microstructure. This fundamental

fractions of solid particles, distributed in size from knowledge will benefit a host of technologies,

submicron to several hundred microns, requires including geothermal energy production, petroleum

the ability to predict the rheological and flow production and refining, and synfuels processing.

properties as a function of the various physical The approach involves a novel combination of

parameters including solids loading, particle shape experiments, numerics, and theory. Experiments

and size distribution, stability characteristics, and primarily involve tracking small balls as they fall

solid and fluid properties. Under the grant a slowly through otherwise quiescent suspensions of

rational theoretical and experimental methodology neutrally buoyant particles. Detailed trajectories of

will be developed for the rheological and flow the balls, obtained either with new experimental

property prediction of dense-phase slurries. The techniques or by numerical simulation, are

approach models a polydisperse suspension as statistically interpreted in terms of the mean

inherently bimodal, wherein it is considered to be settling velocity and the dispersion about the

made up of a fine fraction which behaves mean. Determining the mean settling velocity of

colloidally and imparts to the suspension many of balls that are small relative to the suspended

its important rheological and flow characteristics, particles is a means of measuring the macroscopic

and a coarse fraction which behaves as if it were zero-shear-rate viscosity without significantly

in a pure liquid with the same viscous behavior as disturbing the original microstructure; therefore,

the colloidal suspension and raises the apparent falling-ball rheometry is a powerful tool for use in

viscosity through hydrodynamic interactions. studying the effects of microstructure on the

macroscopic properties of suspensions. The The bimodal model has been shown to be very dispersion about the mean yields information

successful in application to a truly bimodal about the particle interactions. To date, the mean

suspension, where the shear dependent viscosity and dispersivity of a falling sphere's velocity has

behavior of the colloidal fraction is determined been determined as a function of the tracer sphere experimentally. For polymodal multiphase flows size and the suspended particle size, shape, and

the bimodal model is being extended, through concentration. Currently, the pressure drop

analysis and experiment, to find a rational method caused by the falling ball is being measured also.

to divide a continuous size distribution into a This will provide a much needed benchmark

colloidal and a coarse fraction, and to define the problem for numerical studies, as well as provide

effect of a non-uniform size distribution of each another measure of the macroscopic response of

fraction. Additional rheological information on the a suspension as a function of its microstructure.

colloidal fraction, including the effects of the Also begun recently are two studies of boundary

Engineering Research 27 1992
effects in two-phase fluids: the determination of have used the triple torch reactor developed

the torque on a small ball spinning in a suspension previously under this program to obtain good

(a sensitive measure of apparent slip at the mixing of the reactants CH4 and hydrogen with the

boundary) and the determination of the velocity of argon-hydrogen plasma jets.

a small ball rolling down the wall of a container

holding a suspension. Numerical studies are also Based on systematic studies, the effects of

continuing, in which the three-dimensional pressure, plasma composition, substrate material

dynamics of many interacting suspended particles and temperature on deposition rate and quality of

are calculated using the boundary element the films have been determined with deposition

method. rates up to 60 m/hr. Homoepitaxial films have

been grown on diamond seed crystals with growth

rates up to 200 m/hr.

University Of Minnesota

Dept of Aero Eng & Mechanics $ o Modeling of the situation close to the substrate

Minneapolis, Minneapolis, MN MN 55455 01-C indicates extremely steep temperature and 55455 01-C

90-3 concentration gradients pointing to the importance

Stability Studies of Core-Annular Flows of thermal diffusion.

D. Joseph Another plasma reactor with counter flow liquid

The objectives are to understand and control drag injection has been previously used for the

reduction in water lubricated pipelines and to synthesis of fine powders but recently also for

determine conditions of stability in water film diamond deposition. The configuration of this

cooling of water vapor (with phase change) for reactor gives rise to recirculation eddies enhancing

possible application to nuclear safety. We have the residence times of the reactants and products

developed a successful linear theory for predicting in a relatively uniform temperature zone. Very

regimes of lubricated flow of oil and water and we high diamond deposition rates up to 1 mm/hr have

have new experimental results in lubricated flow in been observed with this reactor. A series of

vertical pipes. We are now doing nonlinear theory diagnostic studies have been initiated to facilitate

and preparing experiments on water lubricated an understanding of the main reasons for the

pipelining of coal-oil dispersions. We are observed high deposition rates.

generally supported and encouraged by Shell

Development in Houston. We are world leaders in

this subject. We are going to apply the methods National Academay of Sciences/

we use for water lubricated pipelining to nuclear National Research Council

safety, but we don't know how it will turn out. Washington, DC 20418 $1,064,701

06-C

Department of Energy Integrated 92-3

University Of Minnesota Manufacturing Fellowship Program

Dept of Mechanical Engineering $141,928 B. Kuhn

Minneapolis, MN 55455 06-C

92-4 Recent concern for the loss of competitiveness of

Thermal Plasma Processing of Materials the United States in manufacturing has motivated

E. Pfender a number of studies for the underlying causes and

possible cures for this state of affairs. An

The objective of this research project is to study important conclusion of those studies with

analytically and experimentally specific thermal important consequences for the future is the

plasma processes for materials treatment. recognition of the need for a more integrated

Processes of interest include the synthesis of approach to manufacturing than that prevailing in

ultrafine ceramic powders and of films, our industry. There are two related aspects of this

situation: first is the traditional separation of the

During the past year our efforts have concentrated product design function from the manufacturing

on characterizing the thermal plasma chemical function, and second is the lack of an appreciation

vapor deposition (TPCVD) process of diamond for the process of manufacturing as an integrated

films onto various substrates. In our studies we system, similar to that prevailing in the chemical

Engineering Research 28 1992
process industry. The proposed fellowships are a distribution, the spatial distribution of transit times,

step towards ameliorating that situation. and their means and standard deviations.

The proposed program calls for twelve doctoral Experiments have been performed with downward

fellowships under the aegis of the National flow of water in a packing of uniform diameter,

Academy of Engineering. The fellowships will be poured, glass spheres with a vertical temperature

awarded following a nationally advertised gradient. The transition of the flow structure has

competition. The selection of the fellows will be been observed for a range of temperature

carried out by a panel of 25 distinguished scholars gradients characterized by a Rayleigh number,

in engineering and knowledgeable industrial and different flow rates characterized by a thermal

experts. Each fellowship will be for a three year Peclet number. The transition to mixed forcednonrenewable period. free convection is not abrupt as would be

predicted from the volume-averaged equations of

The objective is to create a pool of Ph.D.'s trained motion and energy. Instead, the flow structure

in the integrated approach to manufacturing, to undergoes distributions which indicate a random

promote academic interest in the field, and to structure which gradually changes to approximate

attract talented professionals to this challenging modes determined from the confining geometry.

area of engineering. Dispersion obtained from the standard deviation of

dye transit times at the plane of observation shows

Based on recent experience in chemical process a generally increasing trend, with a small

industry, it is natural to expect that improved maximum preceding the occurrence of circulating

manufacturing methods will contribute to improved (free convection) flows. The interpretation of these

energy efficiency, to better utilization of scarce observations is aided by numerical solution of the

resources, and to less degradation of the governing equations for grids with randomly

environment. distributed porosity. These show similar

precursors to circulating flow associated with

neutrally buoyant stagnant regions of the bed.

National Institute Of Standards

& Technology

hecal Eng Scnce Division $104000 National Institute Of Standards

Boulder, CO 80303-3328 01-C & Technology

90-3 Thermophyslcs Division $551,000

Convection and Dispersion in Coarse- Gaithersburg, MD 20899 03-B

Packed Beds Boulder, CO 80303 91-5

M. Jones, J. Wolfe, R. Nassimbene

Development of Measurement Capabilities for

One of the most widely used items of industrial the Thermophyslcal Properties of Energyequipment is the packed bed in which, commonly, Related Fluids

a vertical throughflow exists through a packing R. Kayser, J. Levelt Sengers, M. Moldover, W.

which is relatively coarse. The presence of Haynes

temperature or compositional gradients in

conjunction with the stochasticity of the packing on The major objectives of this project are to develop

the scale of observation leads to flow structures state-of-the-art experimental apparatus that can

which may be hard to predict but which are, in any be used to measure the thermophysical properties

case, not uniform. The flow structures observed of a wide range of fluids and fluid mixtures

under these conditions are being studied with the important to the energy, chemical, and energyaid of an array of fiberoptic probes which detect related industries and to carry out carefully

the concentration of a fluorescent dye injected with selected benchmark measurements on key

the throughflow. This technique allows time- systems. The research is being done jointly by

resolved imaging of the flow structure in the plane two groups within the Thermophysics Division of

of the array. Considerable insight into the state of the NIST Chemical Science and Technology

convection may be obtained from some of the Laboratory; one group is located in the

statistics available from individual probe Gaithersburg, MD laboratories and the other at the

responses. These include the residence time Boulder laboratories. The specific measurement

Engineering Hesearch 29 1992
capabilities to be developed in this project include substrate. The goal is to minimize the specific

new apparatus for transport properties (thermal resistance of the contacts using techniques that

conductivity and viscosity), for thermodynamic are compatible with standard Si processing.

properties (pressure-volume-temperature data

and enthalpy), for phase equilibria properties

(vapor-liquid equilibria, coexisting densities, and The City University Of New York

dilute solutions), and for dielectric properties The City College $129,703

(dielectric constant). These new apparatus will The Benjamin Levich Institute 01-C

extend significantly the existing state of the art for for Physlco-Chemlcal Hydrodynamics 90-3

properties measurements and make it possible to New York, NY 10031

study a wide range of complex fluid systems (e.g.,

highly polar, electrically conducting, and reactive The Rheology of Concentrated Suspensions

fluids) under conditions which have been A. Acrivos

previously inaccessible. This project also includes

benchmark experimental measurements on This research program aims to investigate the flow

systems containing alternative refrigerants, on of concentrated suspensions of non-colloidal

aqueous solutions, and on carefully selected particles from the fundamental point of view.

systems with species of diverse size and polarity

that are important to the development of predictive Earlier studies by the principal investigator and his

models for energy-related fluids. associates have shown that the rheology of such

systems is strongly affected by the shear-induced

migration of particles from regions of high shear to. -

National Institute Of Standards low and from high concentrations to low which, by

& Technology distorting the particle concentration profile, can

Electromagnetic Technology Div $98,488 lead to an erroneous interpretation of the"

Boulder, CO 80303 06-C experimental measurements. This shear-induced

89-3 particle diffusion is also responsible for the

Low Resistivity Ohmic Contacts Between phenomenon of viscous resuspension whereby, in

Semiconductors and High-T, the presence of a shear flow, a settled bed of

Superconductors heavy particles can resuspend even under

J. Moreland, J. Ekin conditions of vanishingly small Reynolds numbers.

The purpose of this project is to fabricate and Viscous resuspension is being studied both

characterize contacts between high-T theoretically and experimentally in .various

superconductors (HTS) and semiconductors. unidirectional flows, e.g. a 2-D Hagen-Poiseuille

Developing a method for optimizing the current flow, as well as a Taylor-Couette system. Excelcapacity of such contacts will extend the lent agreement has been found to-date between

application of HTS materials to semiconductor the experimental results and the theoretical

hybrid technologies that have HTS interconnects predictions even though the latter do not entail the

(both on-chip and package) and proximity HTS/ use of adjustable parameters.

semiconductor/HTS SNS Josephson Junctions.

Presently, these are some of the most promising

HTS applications, but an essential first step is the The City University Of New York

development of stable ohmic contacts between The City College $126,000

semiconductors and HTS materials. The Benjamin Levich Institute 03-A

of Physico-Chemical Hydrodynamics 91-3

The project is now focused on YB2Cu3O, (YBCO) New York, NY 10031

thin-films grown on Si wafers. Recent discoveries

have shown that is possible to grow high quality Partial Control of Complex Processing

HTS films on Si using laser ablation deposition Systems

and a yttria stabilized zirconia buffer layer between R. Shinnar, 1. Rinard

the YBCO film and the Si. Processing steps are

being optimized for depositing and patterning Most control theory applies only to systems in

YBCO films on Si to form contact vias to the Si which the number of manipulated variables equals

Engineering Research 30 1992
or exceeds the number of controlled variables, scale system of eddies and with the further

However, in complex systems such as chemical development and refinement of the associated

reactors, refineries, or entire chemical plants, the cascade-renormalization concept of turbulent

number of variables that need to be controlled is flame speed; (2) the intrinsic dynamics and the

larger than the number of manipulated variables pattern formation in premixed flames sustained by

available. the thermal-diffusive and thermal expansion

induced mechanisms of flame instability; (3) the

In many systems one can find a small square hydrodynamical aspects of combustion limits with

control matrix in which exact control of a few particular attention to the phenomena of flame

dominant variables allows one to keep a larger extinction by one- and multiple-scale periodic flow

number of output variables within an acceptable fields and extinction in upward and downward

domain. The choice of the manipulated variables propagating flames in tubes; and (4) the

as well as the controlled variables is very critical to development of new numerical methods especially

ensure stability as well as controllability. assigned for the free-boundary problems of

flame-flow interaction and spontaneous pattern

The goal of the research is to develop a better formation in premixed flames.

understanding of how to approach the control of

such complex systems characterized by both a

large number of state variables and large Northwestern University

uncertainties in the model describing them and to Dept of Civil Engineering $ 0

provide a systematic theoretical framework for Evanston, IL 60208 03-B

such design. 89-3

Quantitative Non-Destructive Evaluation of

This will be done by studying a few well-defined High Temperature Superconducting Materials

complex systems such as a fluid catalytic cracker J Achenbach

and some polymerization reactors. In the first

phase a model of a fluid catalytic cracker suitable A crack in a solid body can, in principle, be

for this purpose was developed. It will be suitable detected and characterized by its effect on an

for both steady state control which is nonlinear incident pulse of ultrasonic wave motion.

and dynamic control and will allow comparisons of

different current decisions and critical review of the The work on this project is concerned with

field. applications of the scattered field approach to the

detection and characterization of cracklike flaws.

The work is both analytical and numerical in

The City University Of New York nature. Several forward solutions to model

The City College $102,500 problems have proven to be very helpful in the

The Benjamin Levich Institute 06-C design of experimental configurations. They are

of Physico-Chemlcal Hydrodynamics 91-3 also valuable in interpreting scattering data for the

New York, NY 10031 inverse problem.

Studies In Premixed Combustion The efficacy of ultrasonic methods to detect and

G. Sivashlnsky characterize a.crack depends on topographical

features of the crack faces, the presence of

The objective of this research is a combined inhomogeneities in the crack's environment, and

analytical and numerical study of the influence of on the mechanical properties in the near-crack

various hydrodynamic, thermal-diffusive and region. In this work the effects on the scattered

reaction rate factors on speed, shape, stability and ultrasonic field of various features of fatigue and

the extinction limits of premixed gas flames. stress corrosion cracks, such as partial crack

Different modelling techniques will be employed to closure, the presence of microcracks and

reduce the study of pertinent combustion systems microvoids, and near-tip zones of different

to simple approximate problems tractable either mechanical properties have been investigated.

analytically or numerically. Specifically, the project Most of the results have been obtained by

is concerned with (1) the dynamics of premixed formulating a set of singular integral equations for

flames spreading through a one- and multiple- the fields on the boundaries of the scattering

Engineering Hesearch 31 1992
obstacles. These equations have been solved disturbances. The nonlinear evolution of threenumerically by the boundary element method, and dimensional layers, including the finite-time

the scattered fields have subsequently been behavior of the secondary instability, is studied by

obtained by using representation integrals. posing various initial-value problems and

numerically integrating the long-wave evolution

For the configurations examined in this work, crack equation.

closure has the most significant effect on far-field

scattering.

Northwestern University

Dept of Eng Scl & App Math $53,000

Northwestern University Evanston, IL 60208 01-C

Dept of Chemical Engineering $235,036 91-3

Evanston, IL 60208 01-B Effects of Capillarity of Macroscopic Flow in

92-3 Porous Media

Stability and Rupture of Thin Fluid Films on M. Miksis

Heated Solids Surfaces

S. Bankoff, S. Davis The objective of this project is to study the effects

of capillarity on the motion of a fluid in a porous

The objective of this work continues to be the material. The primary concern will be the

study of the dynamics, stability, and rupture micromechanics of the fluid motion when

(including contact-line motions) of thin liquid films, interfaces are present and its effect on the

especially with heat and/or mass transfer. The macroscopic flow. These interfaces could exist as

two- and three-dimensional structure of surface a liquid moves into an unsaturated porous material

waves on a heated inclined plane, has been or when there are two phases within the porous

examined and the experimental technique has material, e.g., liquid/gas or liquid/liquid. Attention

been developed to measure accurately the will be directed to understanding and modeling the

surface-wave shapes, frequencies and amplitudes dynamics of these interfaces and then relating

on thin liquid films draining down an inclined plate their dynamics to the macroscopic behavior of the

under adiabatic or heating conditions, for material.

comparison with theoretical predictions.

One of the central concerns of this work will be to

The evolution equation for two-dimensional understand how the motion of the contact line, i.e.,

disturbances incorporates viscosity, gravity, the line of intersection of a liquid/liquid or

surface tension, thermocapillarity, and evaporation liquid/gas interface and a solid, influences the

effects. The linear theory derived from this motion of the fluids. Recent work has been

describes the competition among the instabilities. directed to solving for the evolution of a contact

Numerical solutions of the evolution equation line using analytical and numerical methods. Also

describe the finite-amplitude behavior that recently the dissipation associated with the motion

determines the propensity for dryout of the film. of a contact line and how this dissipation manifests

Among the phenomena that appear are the itself in a macroscopic model of wave propagation

tendency to wave breaking, the creation of in a partially saturated porous material has been

secondary structures, and the pre-emption of investigated. The microscopic flow problems in a

dryout by the mean flow. A three-dimensional porous material can now be studied using these

evolution equation was also derived that contains results. Also attention will be directed to problems

surface-wave instability and nonlinear saturation. concerned with the fundamental modeling of the

Anewsecondarythree-dimensional instability was motion of a contact line. This is an important

identified. Unlike other secondary instabilities aspect of the work since the dynamics and

found in many shear flows, the instability does not dissipation associated with the motion is very

require a threshold amplitude, so that all two- dependent upon the model used for the contact

dimensional permanent waves on vertical plates line motion.

become unstable to three-dimensional

Engineering Hesearch 32 1992
Northwestern University Taylor vortex flow - and in solidification - MullinsSchool of Eng & Applied Science $ 0 Sekerka instability. Such structures also serve as

Evanston, IL 60208-3120 06-C paradigms for non-equilibrium structures in

91-3 general which arise in other fields such as

Mixing of Immiscible Fluids In Chaotic Flows chemistry and mechanics. Structures in spatially

and Related Issues extended systems provide a link between lowJ. Ofttno dimensional systems and high-dimensional ones

which are fundamental in developed turbulence.

This project seeks basic experimental and

theoretical understanding of mixing and dispersion Solitons in integrable conservative systems are

of viscous fluids, and it is relevant to applications well understood. Since Hopf bifurcation in binary

such as processing of polymers. The work mixtures gives rise to coupled complex Ginzburgconsists of several inter-related sub-parts: (i) Landau equations, the localized wave trains have

stretching and breakup of filaments under been described as dissipative perturbed solitons.

supercritical conditions in chaotic flows, (ii) However, it has been found that the predictions of

analysis of details of breakup and sub-satellite the complex Ginzburg-Landau equations disagree

formation at small scales, (iii) understanding of the with certain aspects of experimental observations.

statistics of drop size distributions produced for The PI proposes to investigate binary-mixture

different viscosity ratios. Issues (i-ii) form the convection building on the extended Ginzburgbasis for the understanding of (iii). The drop size Landau equations which he has derived recently.

distribution is consistent with scaling assuming that His extended Ginzburg-Landau equations

moderately extended filaments behave passively incorporate an additional slow time-scale due to

and that stretching in chaotic flows behaves as a the presence of slow mass diffusion.

multiplicative process with weekly correlated steps. The proposed research will be conducted in the

More recently we have extended our investigation following areas: (1) Ginzburg-Landau (GL)

in two new directions: (iv) Mixing of equal volumes equations coupled to a mean field for binaryof fluids using the marker and cell technique; and mixture convection with emphasis on the

(v) Investigation of the role of rheology in chaotic microscopic equations, derivation of the extended

mixing processes. Item (iv) focuses on the early GL equations, and investigation of the extended

stages of the mixing process, before scenario (i) GL equations, (2) evolution of domain structures

takes place. Studies under item (v) comprise both with emphasis on steady structures and oscillatory

experimental and computational investigations of structures.

steady and time-periodic flow of a constant

viscosity, elastic fluid in a two-dimensional

eccentric cylindrical geometry. Several results University Of Notre Dame

have already been obtained for this case. Department of Chemical Engineering $62,916

Notre Dame, IN 46556 01-C

92-3

Northwestern University Wave Dynamics on Falling Films and Its

Dept of Eng Scl & App Math $74,814 Effects on Heat/Mass Transfer

Evanston, IL 60208 06-C H-C Chang

92-3

Stability and Dynamics of Spatio-Temporal Liquid films falling under the force of gravity is

Structures extremely unstable with several unique dynamic

H. Riecke characteristics. The interfacial waves which result

from these instabilities are able to transfer large

This research will be concerned with a study of amounts of heat or mass into and across the liquid

physical systems which exhibit a transition from a phase. However, both the nonlinear wave

homogeneous state to a spatial and/or temporal evolution and the fundamental transfer

structure when driven sufficiently far from enhancement mechanism remain largely

thermodynamic equilibrium. Examples of such unexplored. The project aims to carry out a

non-equilibrium structures are found in fluid fundamental study of the nonlinear and spatial

dynamics - Rayleigh-Benard convection and evolution of the interfacial waves from first

Engineering Hesearch 33 1992
principles. A weakly nonlinear analysis will interpreted using linear and nonlinear analysis,

scrutinize the evolution of wave spectra based on spatially-varying disturbances, of the

downstream especially the unique cascading of Navier-Stokes equations. Additional insight

energy to lower wave frequencies. A mixed comes from some of the recent developments in

spectral finite-element scheme for free surface understanding the generic behavior of nonlinear

problems will then be used to extend the analytical dynamical systems (e.g. intermittency and chaos)

results. The feasibility of preventing or delaying but with careful recognition of the differences

this transition to turbulence using a recent theory between open systems and the typically-studied

for chaos control will be analyzed. A strongly closed systems (e.g. Taylor-Couette flow).

nonlinear theory will be developed to consruct the

large solitary waves that are created downstream

by secondary transition due to nonlinear excitation. Oak Ridge National Laboratory

Interaction of these solitary waves that cause non- Engineering Physics $1,096,000

stationary three-dimensional waves will be and Mathematics Division 03-C

examined and the results wiii be used to achieve Oak Ridge, TN 37831 87-5

quantitative understanding of the heat/mass

transfer enhancement mechanism. Of particular Center for Engineering Systems Advanced

interest is the role of chaotic mixing which allows Research (CESAR)

transport across the separating streamline of the R. Mann, F. Pin

circulation regions in large solitary waves.

The Center for Engineering Systems Advanced

Research [CESAR] is established at Oak Ridge

University Of Notre Dame National Laboratory to address long-range,

Department of Chemical Engineering $54,000 energy-related research in intelligent machine

Notre Dame, IN 46556 01-C systems. These systems are intended to plan and

91-3 perform a variety of tasks in incompletely known

Study of Interfacial Behavior in Cocurrent environments, given only qualitatively specified

Gas-Liquid Flows goals. The Center provides a focal point for

M. McCready interdisciplinary research in machine intelligence,

cognitive systems, advanced control, and systems

The objectives of this work are to develop an engineering. Research objectives are chosen to

understanding of various types of small-scale (e.g. address the technology-base requirements for

waves) and large scale (e.g. slugs) disturbances DOE missions that rely on the use of robotics and

which are observed in cocurrent gas-liquid flows. intelligent machines. In particular, research

concentrates on issues related to autonomous

Typical gas-liquid systems are "open" flows where systems, unstructured dynamic work

there is no feedback of information between the environments, and multiple cooperating robotic

inlet and exit. It is important to determine to what systems. Results from CESAR research in

extent the ubiquitous time-varying fluctuations at automation-related technologies and intelligent

the inlet, which may be of small or large machines can increase productivity and safety in

amplitude, can be expected to affect the qualitative the development and operations of DOEor quantitative behavior of the downstream flow. sponsored systems. Potential and actual

For example, it appears that close to neutral applications include emergency situations, remote

stability in a stratified flow, conditions exist where operations, resource exploration, transportation

the irregularity in the interfacial waves can be systems, advanced power generation systems,

traced to inlet noise. However for other nearby and environmental restoration and waste

conditions the waves show no evidence of the management.

effects of inlet noise.

CESAR is intended to be a national resource, and

The present approach is to characterize these a major objective is to disseminate R&D

flows by using experimental measurements of accomplishments freely and comprehensively.

wavelength and amplitude for periodic waves, and Results and technology advancements are

amplitude and time-spacing between irregular distributed through publications in the scientific

disturbances. These measurements are literature, through organization of workshops on

Engineering Hesearch 34 1992
selected topics, and through the development of are not well defined, since they may contain three

prototype systems that demonstrate concepts and or four interacting phases, including a changing

new methodologies. CESAR cooperates with gas phase. The coupling of hydrodynamics, gas

universities, laboratories and industry, serving as generation or depletion, gradients of phase

a collaborative research facility to provide guests fractions, and biokinetics in continuous columnar

with access to state-of-the-art and often unique systems will be investigated and predictive

equipment in a stimulating research environment, mathematical models will be developed.

Oak Ridge National Laboratory Ohio State University

Chemical Technology Division $108,000 Physics Department $69,000

Oak Ridge, TN 37831 06-A Columbus, OH 43210 06-C

89-3 91-3

Bioprocess Engineering Research for Energy Turbulence and Spatio-Temporal Chaos

Applications C. Jayaprakash, F. Hayot

C. Scott

This program deals with the dynamics of nonThis program will support engineering research in linear systems with many degrees of freedom.

three primary areas that are critical to an

expanding use of advanced bioprocessing systems An important issue in this area concerns the extent

for energy production and conservation: (1) to which deterministic chaos can simulate the

efficient biocatalytic systems, (2) innovative effect of external noise. Effective stochastic

bioseparations approaches, (3) advanced equations that describe the long wavelength

bioreactor concepts. properties of partial differential equations (such as

the Kuramoto-Sivashinsky equation) are being

Efficient biocatalytic systems - Several advanced studied. This is done numerically by explicit

bioreactor concepts require that the biological elimination of short wavelength modes with an

catalyst (microorganisms or active fractions) be emphasis on interpreting the physical basis of the

retained in the bioreactor at high concentrations in parameters in the effective equations.

a microenvironment that enhances biological

activity. A fundamental understanding of the basic A focus of current research in the field is generic

kinetics and dynamics of such biocatalyst systems scale invariance (algebraic decay of spatial

and a predictive mathematical model will be correlations without tuning external parameters ).

developed. The aim of projects underway include

understanding how a conserved mode can induce

Innovative bioseparations approaches-Advanced scale invariance in non-conserved modes and

separations concepts will be needed to isolate or elucidating :different mechanisms that can lead to

concentrate the dilute aqueous components of generic scale invariance by studying model

bioconversion systems or waste streams from systems.

energy processes. The research emphasis will be

on separation concepts that utilize solid-fluid Interface models with a finite density of positive

interactions with an initial study of the use of Lapunov exponents and structure functions that

biological materials (certain microorganisms and grow as power laws are being investigated to

plant and animal tissue) as bioadsorbents for the understand features of fully developed turbulence.

isolation and concentration of dissolved metals.

Extensive numerical simulations of resistively

Advanced bioreactor/biosorber concepts - Fixed- shunted junction models of Josephson junction

and fluidized-bed bioreactors and/or biosorbers arrays and complex Ginzburg-Landau equations

using immobilized bioreagents are advanced are being carried out to understand spatioconcepts that have the potential for significantly temporal chaos and pattern formation.

increasing productivity. However, such systems

Engineering Research 35 1992
Ohio State University of singularities in the model equations; next, more

Mathematics Department $66,116 general boundary conditions will be considered to

Columbus, OH 43210 06-C conform to a broader class of physically realistic

92-3 situations; finally some intrinsically nonlinear

The Evolution of a Hele-Shaw Interface and aspects of dendritic growth will be examined.

Related Problems in Dendritic Crystal Growth

S. Tanveer Oregon State University

A cell consisting of two parallel plates separated Dept of Mechanical Engineering $105,479

by a thin layer of liquid, the so-called Hele-Shaw Corvallis, OR 97331-6001 01-B

cell, serves as a model of a porous medium. 91-3

Using it one can perform laboratory experiments Radiative Transfer Through an Array of

which may be difficult to carry out in an actual Discrete Surfaces

porous medium. For example one can readily J. Welty

observe the displacement of a more viscous fluid

by a less viscous one, such as is taken advantage Determination of the radiative heat transfer

of in secondary oil recovery methods. Most through a given volume is straightforward when

mathematical models of the displacement process the number of objects in the volume is small or

studied to date have dealt with steady states and when the volume is occupied by a continuous

their stability. Under those conditions solutions medium, such as an aerosol or gas. However,

can be obtained even if the surface tension at the when the volume is occupied by a large number of

interface between the two fluids is ignored. As to discrete objects, either a Monte Carlo numerical

the initial value problem, it has been found that model must be used, or some assumptions must

ignoring surface tension leads to an ill-posed be made to treat the collection of objects as

problem in the sense that nonphysical cusps form though it is a continuous medium. This research

at the interface in a finite time. is directed at characterizing the radiative transfer

through arrays of objects as a function of array

Experimentally it is found that when the surface geometry.

tension is small no steady state is reached and the

interface continues to deform into a finer and finer The primary goal of this research has been the

fractal-like structure. experimental measurement of radiative transfer

through arrays of fixed, discrete surfaces. The

Recent work by the proposer has revealed that it independent variables are array packing

is possible to imbed the ill-posed problem into a arrangement and density, array element shape,

well-posed one so as to clarify what happens and angle of the incident beam. The results are in

when the surface tension tends to zero. The the form of a forward scattering phase function for

proposed research is a logical extension of the each discrete position across the exit plane of

preliminary results obtained heretofore. each array. In addition, a bi-directional

reflectometer covering a full hemisphere has been

Specifically, detailed calculations will be carried designed and built for use in accurately

out to examine how the singularities in the model determining array surface properties, a necessity

equations are related to the evolution of the shape for accurate numerical modeling of the radiative

of the interface; second, the results obtained for transfer process.

the Hele-Shaw cell will be extended to study the

time evolution of the surface of a growing crystal This research is being conducted in coordination

with dendrites; third, statistics of the observed with a project at Battelle, Pacific Northwest

patterns will be related to the statistical distribution Laboratory, to numerically model radiative transfer

through an array of fixed discrete surfaces.

Engineering Research 36 1992
Pacific Northwest Laboratory University Of Pennsylvania

Battelle Memorial Institute $104,000 Mechanical Engineering Dept $101,381

Richland, WA 99352 01-B Philadelphia, PA 19104 06-C

91-3 92-3

Radiative Transfer Through Arrays of Active Control of Convection

Discrete Surfaces with Fixed Orientation H. Bau

M. Drost

It is proposed to study theoretically and

Radiative heat transfer in an array of discrete experimentally the use of active, feedback control

surfaces is an important and poorly understood strategies to alter the structure of convection. The

class of radiative heat transfer problems. The work focuses on controlling convective currents in

objective of this study is to develop an a fluid layer contained in a vertical upright cylinder

understanding of the impact of array geometry, heated from below and cooled from above (the

surface properties, and incident radiation Rayleigh-Benard problem). By introducing small

characteristics on radiation heat transfer in the perturbations in boundary conditions, it is planned

array. The results of the study will be used to to (i) stabilize the no-motion state of the

establish criteria for the valid application of Rayleigh-Benard convection (delay to higher

participating media models to arrays of fixed values of the Rayleigh number the transition from

discrete surfaces. the no-motion to the motion state); and (ii)

suppress (laminarize) oscillatory, chaotic

The approach consists of using an innovative convection. The proposed work is the continuation

Monte Carlo model to evaluate radiation heat of an effort in which it was successfully

transfer in arrays of fixed discrete surfaces with a demonstrated that feedback control can be used in

range of array configurations. The Monte Carlo a thermal convection loop to tame chaos. The

model will be validated by comparison with results of the proposed work may be of

experimental results being developed at Oregon importance, among other things, to materials

State University. The Monte Carlo simulations will processing and crystal growth applications in

be used as a benchmark for comparisons with which it is desired to eliminate convective currents

different analytical approaches the model the array or suppress oscillatory convection. What is

as a participating medium. learned during this research may also be useful for

devising control strategies for other non-linear flow

FY 1992 accomplishments consist of: 1) the Monte phenomena.

Carlo code has been completed and validated

against other Monte Carlo, 2) preliminary

parametric studies have been conducted and show Pennsylvania State University

that typical arrays have strongly nonhomogeneous Mechanical Engineering Dept $111,417

and anisotropic optical properties making it difficult University Park PA 16802 06-B

to model the arrays as participating media, 3) 92-3

parametric studies have shown that three Experments on the Gas Dynamics of the

dimensional surface properties variations can have HVOF Thermal Spray Process

a significant effect on Monte Carlo simulations and G. Settles

need to be considered by other researcher. 4) One

technical paper was published in FY 92 and two Flame sprays are an alternative to thermal plasma

journal articles have been prepared for publication sprays for coating materials. However, until now

in FY 1993. the quality of the coatings produced with flame

Engineering Research 37 1992
sprays was lower than that produced with thermal condensation in multicomponent gas mixtures. The

plasmas. Recently high velocity oxy-fuel (HVOF) program goals are: (1) to improve basic

sprays have been shown to share some desirable understanding of nucleation and droplet growth,

characteristics with thermal plasma sprays, (2) to stringently test theories of nucleation at high

including the possibility of producing high density nucleation rates and under nonisothermal

coatings. Since they operate at lower conditions, (3) to develop improved theories where

temperatures, HVOF sprays seem to offer an needed, (4) to enlarge the data base for systems

economical alternative to thermal plasma of both fundamental and practical interest, and (5)

processing, as well as some technical advantages, to provide reliable means for predicting the

such as lesser decomposition and oxidation rates. behavior of mixtures in practical devices and in the

atmosphere. Condensible vapors, mixed with a

While some commercial HVOF equipment has carrier gas, are cooled in a supersonic Laval

been developed, it appears that none of it has nozzle to obtain high nucleation rates under

implemented the basic principles of gas dynamics steady state conditions. Interferometry and laser

in its design. The main objective of this research light scattering are used to detect the "onset" of

is to conduct an experimental study of the gas condensation and to monitor subsequent droplet

dynamics of HVOF thermal sprays. The results of growth. Theoretical calculations of the droplet size

the experiments will serve as the basis for a model distribution along the flow axis are performed to

of the process, which then can be used to control assess competing theories of nucleation and

and optimize it. droplet growth.

An attractive aspect of the proposal is the Experimental and theoretical results on water

possibility of utilizing in this context much of the vapor condensation have shown that the latent

knowledge gained in advancing high-speed heat release disturbing the gas flow at onset is

aeronautics and rocketry. due mainly to the condensational growth of large

numbers of large (5-9 nm radius) droplets. These

Specific topics to be addressed are: results amend an older view that attributes onset

solely to the rapid nucleation of very tiny

1) Nozzle design and operation - controlling the microclusters. Currently, nozzle experiments on

expansion of the spray jet. binary vapor condensation are being conducted,

and a new experimental apparatus is being

2) Turbulent mixing with the surrounding air - constructed to study binary nucleation in mixtures

minimizing the effects of compressible turbulence of sulfuric acid and water vapor.

on the quality of the spray jet.

3) Analysis of coatings produced with an Princeton University

experimental apparatus embodying gas dynamics Dept of Mech & Aero Eng $96,000

principles in its design. Princeton, NJ 08544 06-B

90-3

The results of the experiments will be incorporated Mechanisms and Enhancements of Flame

in a physical-mathematical model of the coating Stabilization

process. C. Law

The program aims to gain fundamental

Physical Sciences Inc. understanding of the structure and stabilization of

20 New England Business Center $129,861 premixed and diffusion flames through theoretical

Andover, MA 01810 06-A and experimental investigations. The following

92-4 major projects were completed during the reporting

Experimental and Theoretical Studies of period.

Multicomponent Vapor Condensation

M. Frish, G. Wllemski A unified chain-thermal theory of flammability

limits was formulated. This theory describes the

This research program comprises experimental steady propagation of the one-dimensional planar

and theoretical studies of nucleation and flame, with radiative heat loss, in the

Engineering Hesearch38 1992
doubly-infinite domain; the incipient failure for Both theoretical and computer-simulation

such a propagation mode would indicate the limit techniques have been employed to quantitatively

of flammability. Detailed transport and reaction characterize the microstructure and compute the

schemes are allowed through numerical transport properties of disordered media.

simulation. Results reproduce the characteristic Statistical-mechanical theory has been used to

extinction turning-point behavior due to heat loss. obtain n-point distribution functions and to study

It is further shown that at the state of the turning percolation phenomena in continuum

point, the relative sensitivity of the dominant random-media models. This has led to accurate

termination reaction to the dominant branching predictions of transport properties of realistic

reaction varies exponentially with system models of isotropic as well as anisotropic

parameters, indicating the signilficant reductin in heterogeneous media. An efficient Brownian

the net reaction rate and thereby the propensity to motion computer-simulation methodology has

extinction in the presence of heat loss. The been employed to yield exactly effective diffusion

present study allows first-principle determination parameters for a host of useful models. Rigorous

of the flammability limits of gaseous mixtures. relations which link the fluid permeability to length

cales obtainable from Nuclear Magnetic

An investigation was conducted for the Resonance experiments have been derived.

stabilization of an inverted flame. Contrary to

prevailing concepts, present experimental results

show that flame stabilization and consequently Purdue University

blowoff can be achieved without heat loss to the School of Mechanical Engineering $93,290

stabilizing rod. A theory was formulated, allowing West Lafayette, IN 47907 01-C

for the active modification of the flame speed by 90-3

flame curvature and flow nonuniformity Effect of Forced and Natural Convection on

characterizing the rear stagnation flow in the Solidification of Binary Mixtures

stabilizing region. Predicted results using this F. Incropera

alternate stabilization mechanism agree well with

the experimental observations. This study deals with the influence of combined

convection mechanisms on the solidification of

binary systems. A major accomplishment of

Princeton University research performed to date has been the

Dept of Civil Engineering $70,676 development and numerical solution of a

Princeton, NJ 08544 06-A continuum model, which uses a single set of

92-1 equations to predict transport phenomena in the

Transport Properties Of Disordered Porous liquid, "mushy" (two-phase), and solid regions of

Media From The Microstructure the mixture. Calculations have been performed for

S. Torquato two-dimensional, aqueous salt solutions involving

forced convection, thermo/solutal natural

This research program is concerned with the convection, and/or thermo/diffusocapillary

quantitative relationship between transport convection. The calculations have revealed a

properties of a disordered heterogeneous medium wide variety of rich and robust flow conditions,

that arise in various energy-related problems (e.g., including important physical features of the

thermal or electrical conductivity, trapping rate, solidification process which have been observed

and the fluid permeability) and its microstructure. experimentally but have heretofore eluded

In particular, we shall focus our attention on prediction. These features include doublestudying the effect of: porosity, spatial distribution diffusive layering in the melt, development of an

of the phase elements, interfacial surface irregular liquidus front, remelting of solid,

statistics, anisotropy, and size distribution of the development of flow channels in the mushy region,

phase elements, on the effective properties of and the establishment of characteristic

models of both unconsolidated media (e.g., soils macrosegregation patterns (regions of significantly

and packed beds of discrete particles) and different composition) in the final solid.

consolidated media (e.g., sandstones and sintered

materials).

Engineering Hesearch 39 1992
The primary objective of current studies is to research program is expected to lead to a) local

determine the manner in which externally imposed instrumentation methods for detailed interfacial

forces influence thermo/solutal convection in the characteristics, b) data for local interfacial area,

mushy and liquid regions during solidification of a void fraction, relative velocity and wave

binary mixture. A special goal is to determine propagation velocity, and c) phenomenological

means by which the forces may be used to offset models for interfacial area and interfacial structural

or dampen thermo/solutal convection, thereby changes.

reducing macrosegregation and attendant casting

defects. Separate consideration is being given to

the effects of magnetic and centrifugal forces on Rensselaer Polytechnic Institute

solidification in binary metallic alloys and aqueous Dept of Mechanical Eng, $125,500

salt solutions, respectively. Predictions based on Aeronautical Eng Mechanics 01-B

the continuum model are being compared with Troy, NY 12180-3590 89-4

measurements obtained for metallic (Pb-Sn) and

aqueous (NH4 CI-H 20) systems. Ultimate Limits of Boiling Heat Fluxes

A. Bergles, M. Jensen

Purdue University This study is directed toward the thermal-hydraulic

School of Nuclear Engineering $108,000 behavior of water and aqueous mixtures, flowing

West Lafayette, IN 47907 01-C in plain tubes and in tubes with enhancement

90-3 devices, at very high heat fluxes. The mode of

Interfacial Area and Interfacial Transfer in heat transfer is sub-cooled nucleate boiling, and

Two-Phase Flow the limiting phenomenon is the critical heat flux

M. Ishil (CHF). Very large heat fluxes can be

accommodated on a steady basis with pure water

The objective of the research program is to by use of large subcoolings, high velocities, small

develop instrumentation methods, experimental tube diameters; and short tubes. It is expected

data base and analysis leading to predictive that simultaneous use of several enhancement

models for describing the interfacial structure and techniques will extend the maximum heat flux to at

behaviors of two-phase flows. In terms of the flow least 5x108W/m2, which would be higher than that

structure, the local void fraction, interfacial area reported in any study to date. The wall

concentration, fluid particle size distribution and temperature characteristics, usually presented as

flow patterns in vertical two-phase flow systems a boiling curve, are unknown at such high heat

are studied in detail. For the purpose of fluxes.

understanding the dynamic behaviors, the

interfacial velocity, wave characteristics and An experimental program is systematically

coalescence and disintegration of fluid particles investigating the effects of subcooling, velocity,

are investigated. Special emphasis is placed on tube geometry, and enhancement techniques on

developing the four-sensor and five-sensor CHF, the boiling curve, and the pressure drop.

resistivity probe method and improving the The CHF without enhancement has been

double-sensor resistivity probe method. A second correlated as a function of flow and geo-metrical

emphasis is on the system size and entrance variables using the present data base of over 200

effects on the interfacial characteristics described points as well as data obtained by other

above. The changes in the interfacial structures investigators; The experiments are complemented

and flow regimes as a function of an axial location by visual observations and mechanically-based

are measured experimentally. This information models for CHF under normal and enhanced

together with the local measurements from the conditions.

probe method are used to study the mechanisms

of flow regime transitions. This research is part of A thesis (C.L. Vandervort, Ph.D.) and interim

a joint program between the University of report (HTL-9) describe the progress to date.

Wisconsin-Milwaukee (Kojasoy) and Purdue. The

Engineering Research 40 1992
Rensselaer Polytechnic Institute Rensselaer Polytechnic Institute

Dept of Mechanical Engineering, $134,000 Dept of Nuc Eng & Eng Physics $128,000

Aeronautical Eng & Mechanics 01-A Troy, NY 12180-3590 06-C

Troy, NY 12180-3590 91-3 89-4

The Continuum Modeling of Two-Phase

Inelastic Deformation and Damage at High Systems

Temperature R. Lahey, Jr., D. Drew

E. Krempl

The primary objective of the research being

A combined theoretical and experimental conducted is to develop a mathematically

investigation is performed to study the biaxial consistent multidimensional two-fluid model which

deformation and failure behavior of engineering agrees with data and satisfies all the constraints

alloys under low-cycle fatigue conditions at implied by physical laws and the postulates of

elevated temperature. The purpose is to continuum mechanics.

characterize the material behavior in mathematical

equations which are ultimately intended for use in To this end, interfacial closure laws are being

inelastic stress analysis and life prediction. developed such that two-fluid models can be used

Creep-fatigue interaction and ratchetting are of to predict many important phenomena, such as the

special concern. The long-term goal is the evolution of interfacial area density and flow

development of a finite element program that can regime transition. Void wave phenomena are also

directly calculate the life-to-crack initiation of a being investigated, both analytically and

component under a given load history. experimentally, in order to assess and thoroughly

understand the effect of the proposed closure laws

An MTS servohydraulic axial/torsion test system on the void wave eigenvalues of the two-fluid

together with an MTS Data/Control Processor model (i.e., to study well-posedness).

provides biaxial rate controlled loading of suitably

designed tubular specimens. Induction heating It is intended that the results of this research will

(10 kHz frequency), MTS biaxial grips and an MTS significantly advance the state-of-the-art in the

biaxial extensometer are available together with a two-fluid modeling of two-phase flows such that,

reversing direct current potential drop facility for in the future, multidimensional two-fluid models

testing from ambient temperature to 1000°C. The can be used with confidence for many problems of

potential drop measurements are intended for practical interest.

early monitoring of damage during cyclic loading.

Biaxial experiments on AISI Type 304 under low- Rensselaer Polytechnic Institute

cycle fatigue conditions were performed at 538C Dept of Chemical Engineering $87,500

with several probes for potential drop measure- TroyNY 12180-3590 01-C

ments on the gage section. Voltage drop readings 89-4

increase with cycles and are high in regions close Microcomputer Enhanced Optical

to the final fatigue crack. Data analysis based on Investigation of Spreading and Evaporative

Fast Fourier Transform techniques are being used rocesses In Ultra-Thin Films

for the interpretation of the readings. P. Wayner, Jr.

Uniaxial testing on modified 9Cr-1Mo steel at The physicochemical phenomena associated with

5380C showed significant rate sensitivity, fluid flow and change-of-phase heat transfer in

relaxation and evidence of influence of recovery of ultra-thin (thickness less than 10-5 m) liquid films

state on the deformation behavior. Accordingly are being studied. Microscopic image-processing

the viscoplasticity theory based on overstress equipment, procedures, and related computer

(VBO) was modified to include the representation programs are being developed to improve data

of recovery of state. The new formulation was resolution and automate data acquisition. First, the

able to reproduce the observed behavior. The image processing equipment are being developed uniaxial VBO theory is now being generalized for and used in conjunction with an interferometer

finite andeformation three dimensionsdesigned to study the transient film thickness in

draining and evaporating films. The glass cell is

Engineering Research 41 1992
designed to optimize temperature control, the axial tendon force. In particular, the high

cleanliness and simplicity. The optical data is frequency response at the pitch natural frequency

obtained using a video camera attached to a will have a significant impact on the fatigue design

microscope through which the interference fringes of the tendons.

are recorded. Transport processes in polar and

non-polar fluids, with and without heat transfer,

are being experimentally studied and analyzed. University Of Rochester

Dept of Physics and Astronomy $69,500 Using the results of these studies, an ellipsometer Rochester, NY 14627 06-C

with a complementary interferometer has been 92-3

designed and is being constructed. The long term Flux Flow, Pinning, and Resistive Behavior in

objective is to determine the heat transfer Superconducting Networks

characteristics of evaporating ultra-thin films. The . Teltel

near term objective is to develop microscopic

image-processing equipment and a The motion of vortex structures, in response to

complementary heat applied currents, is a major source of resistance in

transfer cell. superconducting networks in magnetic fields.

Systems of interest include regular Josephson

junction arrays and type II superconductors, such

Rice University as the new granular high Tc ceramics. Numerical

Dept of Civil Engineering $87,560 simulations of finite temperature, current carrying,

Houston, TX 77251 01-A networks will be carried out to provide a

91-3 characterization of vortex response in nonStochastic Quadrization for Probabilistic equilibrium situations. For periodic networks,

Analysis of Large Compliant Off-Shore current-voltage (I-V) characteristics will be

Structures computed and compared with experimental results.

P. Spanos The effects on resistivity of transitions from pinned

to unpinned or to melted vortex structures, will be

A new technique is developed to evaluate the investigated. For disordered networks, the effects

response statistics of a Tension Leg Platform of pinning in producing metastable vortex

subject to viscous and potential first and second structures leading to glassy behavior will be

order forces. Since the drag force nonlinearity is explored.

not of a polynomial type, it is treated by the

equivalent quadratization method. Accordingly, To date, simulations have been carried out for two

the function representing the drag forces is dimensional regular Josephson junction arrays, as

replaced by a multidimensional polynomial the well as arrays with random vortex pinning sites.

coefficients of which are evaluated so as to Various values of applied magnetic field have

minimize the norm of the approximation error. A been studied and I-V characteristics and resistivity

third order Gram-Charlier expansion of the were computed and related to vortex structure.

probability distribution of the response is then We have also simulated the equilibrium behavior

implemented to estimate the probability distribution of fluctuating vortex lines in a three dimensional

of the nonGaussian response quantities. The network, as a model for high Tc superconductors.

quadratization results agree very well with Melting of the vortex line lattice into a line liquid,

simulation results for a wide range of sea states. and properties of the line liquid, have been

For moderate to severe wave states, the surge investigated and compared with recent theoretical

response of a Tension Leg Platform is significantly results.

affected by higher order wave forces. Of the

quadratic forces considered, all have a significant This research will greatly enhance our

influence on this response. The Neumann fundamental understanding of behavior in strongly

approximation is found to be non-conservative for fluctuating superconducting materials. The results

predicting the magnitude of the low frequency will have impact in understanding the magnetic

surge response. For operational wave states, both properties of the new high Tc superconductors,

linear and quadratic forces induce significant and in the design of Josephson junction arrays for

responses in the pitch mode, and consequently in use as microwave detectors and generators.

Engineering Research 42 1992
University Of Rochester deterministic scatterers. This gas can be

Dept of Physics and Astronomy $93,186 considered as a dynamical system in a random

Rochester, NY 14627 06-C environment and a beginning has been made to

90-3 prove theorems on its abnormal diffusive behavior.

Coherence Effects In Radiative Energy In addition, the connection with polymer statistics

Transfer on a lattice, noticed before, will be further pursued.

E Wolf 2. A general relation between the transport

coefficients of a fluid in a stationary nonequilibrium

The main objective of this research is the state, near or far from equilibrium, and its two

elucidation of how coherence properties of sources maximal Lyapunov exponents found before, is

affect the spatial and the spectral distribution of further investigated. This relation is based on a

energy in optical fields. The clarification of such pairing rule of conjugate Lyapunov exponents.

questions is of importance for the theory of The class of systems for which this pairing rule

radiative energy transfer and for radiometry with holds is being determined. In addition, computer

sources of different statistical properties. The studies are done to cheek its use under extreme

influence of source correlations in the physical nonequilibrium conditions. 3. An analogy has

parameters of random media with which a field been discovered between the structural relaxation

may interact on the spectral properties of the of atomic liquids and monodisperse concentrated

scattered radiation is also being examined. colloidal suspensions, consisting of spherical particles. This analogy can be understood via the

The progress made so far includes the clarification kinetic theory of a hard sphere model of both fluid

of the relationship between the radiance of a field systems. Applications to the theological behavior

produced by a class of partially coherent optical of concentrated colloidal suspensions are made,

sources and the radiance (specific intensity) of the providing a microscopic approach to fluid rheology.

phemomenological theory; elucidation of effects of

diffracting apertures on spectra of partially

coherent fields; and formulation of laws for Sandia National Laboratories

propagation of the radiance through paraxial Fluid, Thermal, and $14,000

optical systems. Structural Sciences Division 03-B

Albuquerque, NM 87185 92-1

Current research includes the formulation of new

conservation laws in which spectral changes take Two-Phase Flow Measurements by NMR

place and investigations of spectral modifications R. Givler

produced in multiple scattering. The possibility of

determining correlation functions of media from This project will develop nuclear magnetic

observed spectral changes of scattered radiation resonance (NMR) methods to measure velocity

is also being examined. and concentration distributions of both phases in

two-phase flows. Systems to be studied include

concentrated suspension flows in circular tubes,

The Rockefeller University solid-liquid flows in Couette geometries as well as

Department of Physics $85,487 to gas-liquid and liquid-liquid flows.

1230 York Avenue 06-C

New York, NY 10021 92-3 One approach to velocity measurements is to

measure an incremental spatial displacement of

Some Basic Research Problems Related to nuclear spins that are noninvasively tagged

Energy whereas another is to measure the phase

E. Cohen evolution of the nuclear spin precession which

depends on the translational velocity. The first

The present project is concerned with the following method is best suited for flows in uniform

problems. 1. An investigation of the new types of geometries such as pipe flows whereas the

diffusion, discovered in Lorentz lattice gas cellular second, more complex method, is better suited for

automata, is continued. In this gas point particles non-uniform cases such as for nonneutrally

move on a lattice, which is randomly occupied by buoyant flows in a Couette geometry.

Engineering Research 43 1992
In order to improve the capabilities of the Sandia National Laboratories

apparatus to make rapid measurements, a major Combustion Research Facility $ 0

instrumentation upgrade is being performed during Uvermore, CA 94551-0969 06-B

summer and fall of 1991. This consists in a new 90_3

operating system and computer, hardware Structure of Inverse Diffusion Flames in

improvements to the rf electronics, and a shielded Supercritical Fuel/Water Mixtures

magnetic field gradient coil system. The studies of R. Steeper

concentrated suspensions in pipe flow for velocity

and concentration distributions is complete except This research project investigates the structure of

for measurements of particle velocities. The next inverse diffusion flames in supercritical fuel/water

major experimental emphasis will be on liquid- mixtures. Inverse diffusion flames have received

solid flows in an asymmetric Couette device. very little attention in the literature although they

possess unique characteristics that are applicable This work is carried out in collaboration with the to chemical processing and materials synthesis.

Lovelace Medical Foundation. The focus of this project is the specific class of

inverse diffusion flames in which a laminar jet of

oxidizer is introduced into a background of

Sandia National Laboratories hydrocarbon fuel and water at a temperature and

Combustion Research Facility $150,000 pressure above the thermodynamic critical point of

Thermofluids Division 06-B the fuel/water mixture. These flames have direct

Uvermore, CA 94550 90-3 application to the destruction of aqueous and

mixed hazardous wastes, but little is currently

Mixing and Phase Change During known about the ignition, extinction, or stability of

Combustion flames at high pressures, particularly flames at

A. Kerstein supercritical water conditions. Sandia has built a

laboratory-scale supercritical reactor and

The principal focus of this research program is the demonstrated the capability to obtain quasi-steady

development of a turbulent mixing model inverse diffusion flames in supercritical mixtures of

applicable to combustion flows. In work to date, a water and methane. The reactor provides optical

novel computational approach has been access to the reaction zone, and a mapping of

formulated in which turbulent stirring is temperature, species, and velocity fields is

represented by non-linear mappings on a line, planned. Both analytical and numerical models of

iterated according to a stochastic rule that laminar diffusion flames are available to support

incorporates key aspects of the Kolmogorov the experimental efforts, however these models

cascade picture of turbulence. Computations and must be modified to include a supercritical fluid

analysis demonstrate substantially better predictive equation of state and supercritical transport

capability than achieved by previous models of properties.

molecular mixing in turbulent flow. Future work

will involve further analysis of the mathematical

origins of the computed results, refinement of the University Of Southern

model to capture subtle effects such as the California

influence of molecular diffusion on turbulent

transport, and application to unsolved problems of Dept of Mechanical Engineering $106,536

turbulent mixing in non-reacting turbulent shear Los Angeles, CA 90089-1453 01-C

flows and turbulent combusting flows. 91-3 Particle Pressures in Fluidized Beds

Aspects of heterogeneous combustion are also C. Campbell

addressed in this program. Stochastic networkbreakup models are applied, on a macroscopic The particle pressure represents the portion of the

scale, to the morphological evolution of a reacting momentum transport in a fuidized bed that can

porous solid, and on a microscopic scale, to the "be attributed to the motion of particles and their

thermochemical dissociation of a macromolecular interactions. Such forces are responsible for the

fuel such as coal. attrition of fluidized particles and postulated

behaviors of the particle pressure have been used

Engineering Hesearch 44 1992
as a mechanism to explain the stability of efficient magnetic measurement procedures for

homogeneously fluidized beds. But, until recently monitoring neutron embrittlement and biaxial

there have been no measurements of the particle stress.

pressure. Preliminary measurements, in gasfluidized beds, have shown that the particle Magnetic measurement techniques to be assessed

pressures exerted on the side walls are primarily are: (1) magnetic hysteresis loop measurement of

due to the presence of bubbles and that the properties like coercivity and permeability; (2)

magnitude of the average particle pressure scale magabsorption, which measures the impedance of

with the bubble size. The purpose of the present an rf coil brought close to a magnetic sample: (3)

investigation is to continue this work to better Barkhausen noise analysis; (4) magnetically

understand the mechanisms that lead to particle induced velocity change (MIVC) of an ultrasonic

pressure generation in both gas and liquid wave; and (5) harmonic analysis of an ac

fluidized beds. In two-dimensional gas bed, the magnetic hysteresis loon. The model of Sablik et

goal is to determine the distribution of particle al for magnetic hysteresis and uniaxial stress

pressure around an injected two-dimensional effects on magnetic properties will be extended to

bubble as a way of understanding the distribution conditions of biaxial stress and neutron

of particle pressure across the bed. The studies embrittlement. The effects of these conditions on

in the liquid bed will be used to try and understand magnetic probe signals (1) - (5) will be modeled

the behavior of the particle pressure near the point and compared to experiment. In the case of

of initial instability of the bed and the pressure that neutron embrittlement, measurements will be

are generated in the early stages of unstable made on steel samples characterized by Charpy

behavior. In the first year of the project we have tests after previous exposure to various neutron

developed and improved version of the particle fluences.

pressure transducer. The results show that

particle pressures are largely generated in the Project research is important for safety monitoring

wakes of bubbles. The same may not be true for in the nuclear power and gas industries.

a slug, in which case, the bubble spans the bed. Preliminary results on neutron-embrittled samples

We have some qualitative evidence that, in that will be presented at the QNDE Conference in San

case, the largest particle pressures are generated Diego in July 1992.

between the nose of the slug and a boundary wall.

So far, it appears that the particle pressures

generated in a liquid bed are so small (a few Stanford University

Pascals) that they are at the lower boundary of the Dept of Mechanical Engineering $98,695

region that can be resolved with the current Stanford, CA 94305-3030 01-A

transducer; we are planning another radical 91-3

change in the transducer design that will hopefully Stability and Stress Analyses of Surface

resolve these pressures. Morphology of Elastic and Piezoelectric

Materials

H. Gao Southwest Research Institute

6220 Culebra Road $99,912 The goal of this research is to investigate the

San Antonio, TX 78228-0510 03-B mechanical effects of surface morphology of

91-3 elastic and piezoelectric materials. In particular,

Application of Magnetomechanical Hysteresis the project will study the stability of a flat surface

Modeling to Magnetic Techniques for against diffusional perturbations and the stress

Monitoring Neutron Embrittlement and Biaxial concentration caused by surface roughness.

Stress

M. Sablik The surface morphology of materials will be

studied by using a unified perturbation procedure

The project objective is to study the effects of based on the notion of thermodynamic forces and

neutron embrittlement and biaxial stress on signals the energy momentum tensor. The

from various magnetic measurement techniques in thermodynamic forces on material inhomogeneities

steels. It is expected that interaction between such as interfaces and inclusions are a measure

experiment and modeling will lead to design of of the rate at which the total energy varies with the

Engineering Research 45 1992
configurational change of these inhomogeneities. imperfect interfaces, and for stresses in cylindrical

Within the general methodology, any type of and plane layered media. A new methodology to

material and loading condition can be studied as establish conservation laws for dissipative systems

long as the proper forces can be identified. By has been advanced, and a theory of stressed

using corresponding material conservation laws solids prone to damage has been formulated

discovered previously, a systematic analysis of based on the Gibbs free energy.

surfaces of piezoelectric solids can be made.

Preliminary studies have shown that under Another portion of our research has as its

sufficiently large stresses, surfaces of materials objective the development of further understanding

become unstable against a range of diffusional of subsonic and supersonic surface waves and

perturbations bounded by two critical wavelengths. interfacial and bulk waves in anisotropic linear

Even a slight undulation such as micro-level elastic solids. In the past year we have completed

bumps and troughs can result in a substantial a reasonably thorough study of the existence of

stress concentration along a material surface. triply degenerate acoustic axes in these solids,

These concentrations may lead to mechanical including a delineation of restrictions on elastic

failures along the surface and may have more stiffnesses and orientations in crystals of isotropic,

consequences for piezoelectric materials where cubic, hexagonal, trigonal, and tetragonal

the deformation is coupled to an applied electric symmetry which allow for such acoustic axes to

field. occur. Our previous discovery (last year) of the

existence of "one-component surface waves"

In the past year we have also developed a simple (which are necessarily supersonic) is being used

analytical solution to a special class of surface to develop numerical and theoretical methods for

roughness characterized by a cycloidal profile. finding the space of simple reflection in generally

Surprisingly we find that the cycloidal rough anisotropic solids, and to study the connection of

surface is subjected to the same stress singularity this space with supersonic surface waves (both

and stress intensity factor as an array of leaky and pure). New investigations of so-called

periodically spaced semi-infinte cracks. "generalized surface waves" and Stoneley waves

Application of fracture mechanics would predict in pre-stressed anisotropic bimaterials have also

that these two brittle structures fail at the same been undertaken.

bulk stress level, even though there is no apparent

"crack size" associated with the rough surface!

The full significant of this solution is being Stanford University

investigated. W.W. Hansen Lab of Physics $134,678

Stanford, CA 94305-3030 03-B

90-3 Stanford University Optical Techniques for Superconductor

Dept of Mechanical Engineering $175,000 Characterization

Stanford, CA 94305-3030 01-A G. Kino

91-4

Energy Changes In Transforming Solids The aim of this project is to develop a

G. Herrmann, D. Barnett photothermal microscope for non contact testing of

materials. Techniques of this kind are particularly

In the mechanics of solids defects such as well suited to the determination of thermal

inclusions or holes may undergo rearrangements parameters, and anisotropy of small samples.

or changes of form; the energy changes

associated with such rearrangements play a One example of the work is the measurement of

preponderant role in characterizing the gross high temperature superconductors over a range of

response of solids under load to these temperatures from room temperature through the

"transformations". To this end, the critical temperature T down to 20°K. A modulated

heterogenization techniques developed with DOE laser beam, focused to less than I m diameter,

support proves most useful. The method has impinges through a sapphire window onto a

been extended to provide a number of universal sample of Bi-Ca-Sr-Cu-O in a helium cryostat

formulae valid for the average stresses between and periodically modulates its temperature. This

two holes or inclusions, for inclusions with process excites a thermal wave, which can be

Engineering Hesearch 46 1992
detected by the variation in reflected signal conservation of species equations in three space

amplitude of a second focused laser beam, due to dimensions and in time. The experimental results

the change of refractivity with temperature. The suggest that the high resolution required to

sample can be rotated under the beams and the satisfactorily represent the intrusion interfaces will

thermal diffusion coefficient, its anisotropy and its make a conventional modeling approach very

magnitude can be measured from the phase delay difficult, with the number of grid points required to

of the thermal wave. By measuring the amplitude resolve the interfaces excessive, even in the

of the thermal wave, material phase changes context of modern supercomputers. For this

associated with superconductivity can be reason work on implementing an adaptive gridding

measured. A pronounced peak in amplitude is procedure has been commenced.

seen at the critical temperature Tc. Even stronger

effects of this type are observed with charge Adaptive gridding allows the grid to be selectively

density waves in a variety of materials. refined only in those areas where high resolution

is required, thus facilitating large savings in both

computational time and memory requirements.

Stanford University

Dept of Civil Engineering $ 0

Environmental Fluid Mechanics Lab 01-B Stanford University

Stanford, CA 94305-4020 90-3 Mechanical Engineering Dept $441,508

Stanford, CA 94305 03-B

Fluid Dynamics of Double Diffusive Systems 92-4

J. Koseff, R. Street, S. Schladow Advanced Diagnostics for Plasma Chemistry

C. Kruger, M. Cappelli

This project is focused on processes that occur in

a double-diffusive system subject to external This research is concerned with optical diagnostics

forcing, using a combined experimental and for plasma chemistry and plasma processing, with

numerical approach. In particular it addresses a an emphasis on methods which allow for

water body that is continuously stratified in both departures from local thermodynamic equilibrium -

temperature and salinity. The forcing is provided - such as finite chemical reaction rates,

by a combination of a lateral heat flux and a nonequilibrium electron densities and

surface shear. Double-diffusive instabilities and temperatures, and radiation loss effects. Laser

mixed layer deepening occurs in response to this and other optically based methods are being

forcing, resulting in changes to the vertical and developed for measurements of plasma

horizontal fluxes of heat and salt. The goals are parameters including species concentrations and

to (1) understand the initiation and evolution of the temperature. The methods under study include

double diffusive instabilities, (2) quantify the effects Laser Induced Fluorescence and Degenerate Four

on the vertical fluxes, and (3) compare Wave Mixing, and are designed to be applicable

observations of the mixed layer deepening to the whether or not the plasma is in local

existing data for singly stratified systems. The thermodynamic equilibrium, and indeed to assess

experimental component has to date concentrated the importance of nonequilibrium effects under

on the effects of lateral heating. A new 4.0 m long conditions of interest in plasma chemistry.

and 0.8 m wide experimental tank, together with

appurtenant facilities for controlling the initial Results with an induction plasma facility show

stratification, has been commissioned. The end significant nonequilibrium at the exit of a

wall of this tank is uniformly heated using a radiant downstream quartz test section and suggest

source. Fast response thermistor and conductivity possible errors in conventional diagnostics

probes are used to provide vertical profiles, and assuming local thermodynamic equilibrium.

flow visualization is provided by video imaging of Measurements of the radiation source strength in

dye in illuminated planes. Initial findings suggest argon indicate an order-of-magnitude difference

that the nature of resulting convective intrusions is from values reported earlier at temperatures of

a function of two dimensionless stability interest in plasma processing.

parameters. The numerical component involves

using a finite volume formulation of the non-linear To apply this approach to diagnostics to a realistic

Navier-Stokes, conservation of mass, and and promising form of plasma processing, we

Engineering Hesearch 47 1992
have undertaken experiments on diamond Stanford University

synthesis on substrates in the test section of the Dept of Chemistry $95,328

induction torch. Diamond crystals and films have Stanford, CA 94305 03-A

been grown at rates that are at least one order of 92-4

magnitude greater than those characteristic of Degenerate Four-Wave Mixing as a

low-pressure diamond synthesis. Diagnostic of Plasma Chemistry

R. Zare

Recent measurements in the diamond synthesis

environment show that Degenerate Four Wave A need exists for in situ noninstrusive diagnostics

Mixing is a very pomising diagnostic for the for probing trace and highly reactive radical

intensely luminous environments of plasma intermediates in nonequilibrium plasma used for

chemistry. Current measuremtns show a chemical vapor deposition. We propose applying

sensitivity for CH radical concentrations of a few a novel nonlinear spectroscopic technique,

ppm, with a submillimeter spatial resolution. degenerate four-wave mixing (DFWM). The

DFWM signal is a coherent scattered beam at

frequency which is generated by the nonlinear

Stanford University response of the medium to the interaction of three

Dept of Chemistry $142,000 incident waves at the same frequency. The signal

Stanford, CA 94305 06-C is enhaced by a reasonant transition and offers a

92-3 form of Doppler-free spectroscopy with extremely

Thermodynamics and Stochastic Theory of high spectral, spatial, and temporal resolution.

Hydrodynamics and Power Producing Signal detection is remote and does not suffer

Processes from background interference from the bright

J. Ross plasma source. In addition, the phase conjugate

nature of the signal eliminates optical aberration.

Research focuses on the thermodynamic and The environment we propose to study is an

stochastic theory of hydrodynamic processes, such atmospheric-pressure rf-inducively-coupled

as combinations of chemical reactions, diffusion, plasma and the target radicals include CH, CH2,

thermal conduction, and viscus flow. Such C2, CH, and CH3 that are important in plasma

theories have been formulated for each of the synthesis of diamond thin films. The spatial

individual processes, both linear and nonlinear. sensitivity of DFWM will be used to study the

Progress has been made on combinations of coupling of gas-phase and gas-surface chemistry

these processes for a simplified form of the by measuring temperature and concentration

Navier-Stokes equations, the so-called Lorenz profiles. The proposed research will advance

equations. The theory leads to a formulation of an diagnostic techniques for plasma environments

excess work expressed in terms of thermodynamic and provide a better understanding of the plasma

functions, which provides a Liapunov function, chemistry of diamond synthesis.

necessary and sufficient conditions of stability,

criteria of relative stability, and relations to

fluctuations. Work is planned on the formulation of

thermodynamics of nonlinear (auto-catalytic)

chemical reactions which produce work or on

which external work is done; and a similar

formulation for systems with more than one

temperature.

Engineering Research 48 1992
Stevens Institute Of Technology University Of Texas At Austin

Dept of Physics and Engineering $66,932 Ctr for Studies In Statistical Mech $100,003

Hoboken, NJ 07030 06-C and Complex Systems 06-C

92-3 Austin, TX 78712 91-3

Investigation of Transitions From Order to

Chaos In Dynamical Systems The Behavior of Matter Under NonG. Schmidt equilibrium Conditions: Fundamental

Aspects and Applications

This project focuses on the application of I. Prigogine, T. Petrosky

dynamical system (chaos) theory to problems

occurring in nature and technology. The approach This proposal, which is a continuation of previous

is computational as well an analytical. work deals with the behavior of matter under nonequilibrium conditions in terms of microscopic

The mechanism of generation of terrestrial and description. Atheoretical framework for integrating

solar magnetic fields is still not understood. It has "non-integrable" large Poincare systems will be

been recently proposed that the chaotic flow in a applied to the study of a number of interesting

conductive fluid can lead to a fast dynamo, where situations. (1) Application to interacting fields,

an initially small magnetic field increases including classical and quantum electrodynamics:

exponentially with time. Several artificial chaotic The method permits the representation of radiation

systems have been studied computationally, and damping as part of the complex spectrum of the

claims have been made of the presence of fast Liouville operator, and avoids the well-known

dynamo action in these systems. In this work the difficulties of the classical and quantum radiation

question of fast dynamo action in naturally damping theory. (2) Numerical validation of the

occurring systems is studied. A fluid heated from approach: Numerical experiments will be pursued

below gives rise to Rayleigh-Bernard instability in order to verify the quantum formulation.

generating chaotic flow regions. First this flow (the Especially, the collapse of the wave function and

Arter flow) is studied todetermine the dependence the appearance of an equilibrium statistical

of chaotic regions on the instability parameter, the distribution, as predicted by the theory, will be

location of stagnation points and invariant verified. (3) The present work, already well

manifolds. This work is analytical as well as advanced for the definition of unstable particles in

computational. Next a computational study is the frame of a complex spectral representation,

undertaken to determine whether such flows can will be continued. Unstable particles with decaying

generate fast dynamo action. modes cannot simply be identified, since decaying

modes, taken separately, do not carry energy. (4)

Another area of study involves the mixing of The theory gives the possibility to derive new

polymers. Such mixing involves time dependent criteria for the transition to classical chaos by

externally driven, incompressible chaotic flows. studying the complex spectrum of the Louville

The question of which parameter regions produce operator in a form that is appropriate to mapping

large chaotic domains and hence the best mixing problems. (5) The theory goes beyond the nonis being studied. So far excellent agreement has Markovian master equation and permits a new

been found between these computational studies approach for the study or transport processes

and experimental results reported in the scientific (diffusion, viscosity, etc.). (6) Irreversibility

literature. appears to be of special interest in high-energy

problems, and especially to transitions from virtual

to real particles.

Engineering Research 49 1992
University Of Texas At Austin high temperatures or irradiation, and microcracking

Dept of Physics $152,496 in composite materials under fatigue conditions

Austin, TX 78712 06-C may noticeably reduce the stiffness of the material

87-5 and make it anisotropic. Understanding and

Complex Temporal and Spatial Patterns in prediction of these changes are essential for

Nonequilibrium Systems proper design and strength and lifetime

H. Swinney assessments. A new approach to many cracks

problems based on interrelating the average

Dynamical systems methods are being developed tractions on individual cracks is introduced. Its

and used to characterize the formation and advantages are that it yields simple analytical

evolution of temporal and spatial patterns in results which are quite accurate up to very high

systems maintained far from equilibrium. In crack densities and that it can be applied to crack

particular, experiments and analyses are arrays or arbitrary geometry. Relation between

considering electrodeposition of fractal metallic deterioration of elastic properties and "damage" is

clusters, pattern formation in reaction-diffusion discussed.

systems, and instabilities in convecting fluids.

Novel reactors have been developed to search for

chemical patterns (i.e., spatial variations in the United Technologies Res Center

chemical composition), and sustained patterns Propulsion Science Lab $179,995

have been found in several different one- and Silver Lane 03-A

two-dimensional geometries. Bifurcations in these East Hartford, CT 06108 92-1

patterns are studied by varying control parameters, Investigation of PACVD Protective Coating

e.g., the concentrations of the feed chemicals or Processes Using Advanced Diagnostic

the temperature. The observed two-dimensional Techniques

chemical patterns range from the stationary W. Roman, S. Hay, F. Otter, A. Eckbreth

patterns, similar to those predicted by Turing in

1952 but not observed until 1990, to chemical The research objective is the comprehensive

turbulence, which is characterized by large experimental investigation of the fundamental

numbers of defects and a rapid decay of spatial nonequilibrium reactive plasma assisted chemical

correlations. Much needs to be done, both vapor deposition (PACVD) process as applied to

experimentally and theoretically, to characterize hard face coatings (e.g. TiB2 or diamond).

and understand these spatiotemporil patterns. Nonintrusive laser diagnostics (e.g. laser induced

These laboratory experiments together with fluorescence (LIF) and coherent anti-Stokes

numerical and analytic studies of models should Raman spectroscopy (CARS)) are being used to

provide general insights into the formation and probe gas phase species, concentrations and

evolution of patterns in nonequilibrium systems. rotational temperatures in situ. Detailed coating

characterization is accomplished using Auger, Ion

Scattering and secondary ion mass spectroscopies

Tufts University (AES, ISS and SIMS) and complementary

Dept of Mechanical Engineering $59,798 techniques. In addition, coating characteristics

Medford, MA 02155 01-A such as smoothness, adhesion (UTRC custom

88-3 built pin-on-disc apparatus) and hardness (stateEffective Elastic Properties and Constitutive of-the-art nanoindenter apparatus) are measured.

Equations for Brittle Solids Under Gas phase spectroscopy is interpreted through

Compression chemical kinetic modelling and will be correlated to

M. Kachanov coating characteristics thus providing a predictive

capability that is severely lacking in the present

The knowledge of effective elastic properties of science base of advanced protective coatings.

solids with cracks appears to be of increasing These techniques are also applicable to other

engineering importance. Extensive microcracking processes such as PVD, CVD, combustion and

in structural elements working under conditions of thermal plasma deposition. Results to date

include:

Engineering Research 50 1992
1) fabrication of a 5 kW rf PACVD reactor In order to analyze and design a compensator for

system a time-varying system it is important to be able to

2) exploratory spectral emission studies estimate the trend, i.e., predict future values of the

3) development of substrate preparation parameters of the system. An important part of

technology and characterization our project is to assume that the parameters

4) implementation of a ultramicrohardness change in accordance with an internal structure

tester and adhesion test apparatus and viz. a time series. Our goal is to estimate the

measurement of coating hardness and parameters of the internal structure.

elastic modulus

5) coating durability testing using UTRC Thus we propose to investigate in this project an

erosion test facility. identification scheme with internal structure

6) initial characterization of TiB2 and diamond together with recursive coefficient assignment in

coatings real time in order to generate a desirable

7) first time CARS observation of diborane performance in the closed loop.

(B2H6) in a PACVD process

8) in situ axial concentration and temperature

profiles of key species (diborane and H) Washington State University

9) formulation of chemical kinetic models to Dept of Mechanical Engineering $72,000

account for spectral observationsPullman, WA 99164-2920 01-B

10) adapted of pyrolysis mechanism to 91-2

photoinitiated pyrolysis and comparison with Mass and Energy Coupling Effects In

experimental results Multiphase Free Shear Flows

11) proposal of surface species and T. Trouft

heterogeneous reaction mechanism for the

growth of boron from diborane plasma The primary goal of this research program is to

examine the effects of two-way multiphase

coupling on the development of organized vortex

Washington University structures in free shear flows and the resultant

Department of Systems Science $75,664 multiphase dispersion. Previous research studies

and Mathematics 03-A have determined that one-way coupled particle

Saint Louis, MO 63130 90-3 dispersion in free shear flows is strongly

dependent on the vortex structures present in

Dynamical Systems with Internal Structure: these flows and their interactions as well as the

A New Approach to the Problem of Analysis ratio of the particle aerodynamic response time to

and Robust Design of a Time Varying System the time scale of the dominant vortex structures.

B. Ghosh Two types of previously unknown particulate

dispersion processes have been identified. In

The main objective of the proposed project is to mixing layers, where large scale vortex mergers

study design problems for linear time-varying occur regularly, intermediate scale particles are

control systems leading to a robust design via an concentrated into sheet like patterns which

adaptive controller. Specifically, for autoregressive undergo stretching and folding operations. For

moving average systems with time-varying bluff body wakes where large scale vortex mergers

coefficients, it turns out that a good design are not a dominant feature intermediate scale

strategy is to adaptively assign the parameters of particles are focussed into thin regions of high

the closed loop system by a judicious choice of a particle concentrations near the vortex boundaries.

time-varying compensator. The parameters of the

compensator which assign a specified set of Current research efforts are directed towards

coefficients in the closed loop satisfy a nonlinear exploring the effects that two-way momentum,

recursion. We propose to study these recursions mass and energy coupling have on the multiphase

in details. For specific cases, we show that the dispersion processes previously uncovered.

proposed recursion is an Anosov diffeomorphism These efforts involve analytical, numerical and

on a three-dimensional torus. In particular, such experimental investigations. Recent analytical and

a dynamic is chaotic. We feel that our design numerical results indicate that momentum coupling

should try to avoid chaotic dynamics. effects can significantly alter the global stability

Engineering Hesearch 51 1992
and potentially the large scale features of the University Of Wisconsin

multiphase flow field. These multiphase coupling Dept of Chemical Engineering $114,000

effects may have significant importance with Madison, W 53706 03-A

regard to predicting the performance of many 92-3

energy conversion systems. New Process Modeling, Design, and Control

Strategies for Energy Efficiency, High

Product Quality, and Improved Productivity In

University Of Wisconsin the Process Industries

Mechanical Engineering Dept $107,708 W. Ray

Milwaukee, Wl 53201 01-C

90-3- The process industries are having great difficulty

Interfacial Area and Interfacial Transfer in competing in the world market because of high

Two-Phase Flow Systems energy costs, high labor rates, and old technology

G. Kojasoy for many processes. This project is concerned

with the development of process design and

The objective of the research program is to control strategies for improving energy efficiency,

develop instrumentation methods, experimental product quality, and productivity in the process

data base and analysis leading to predictive industry. In particular, (1) the resilient design and

models for describing the interfacial structure and control of chemical reactors, and (2) the operation

behaviors of two-phase flows. In terms of the flow of complex processing systems, will be

structure, the local void fraction, interfacial area investigated. Major emphasis in part (1) will be on

concentration, fluid particle size distribution and two important classes of chemical reactors:

flow patterns in vertical two-phase flow systems polymerization processes and packed bed

are studied in detail. For the purpose of reactors. In part (2), the main focus will be on

understanding the dynamic behaviors, the developing process identification and control

interfacial velocity, wave characteristics and procedures which allow the design of advanced

coalescence and disintegration of fluid particles control systems based on limited process

are investigated. Special emphasis is placed on information and which will work reliably when

developing the four-sensor and five-sensor process parameters change in an unknown

resistivity probe method and improving the manner. Specific topics to be studied include new

double-sensor resistivity probe method. A second process identification procedures, nonlinear

emphasis is on the system size and entrance controller designs, adaptive control methods, and

effects on the interfacial characteristics described techniques for distributed parameter systems.

above. The changes in the interfacial structures Both fundamental and immediately applicable

and flow regimes as a function of an axial location results are expected. The theoretical

are measured experimentally. This information developments are being tested experimentally on

together with the local measurements from the pilot scale equipment in the laboratory. These

probe method are used to study the mechanisms experiments not only allow improvements in

of flow regime transitions. This research is part of theoretical work, but also represent real life

a joint program between Purdue University (Ishii) demonstrations of the effectiveness of the

and the University of Wisconsin-Milwaukee. The methods and of the feasibility of implementing

research program is expected to lead to a) local them in an industrial environment. The new

instrumentation methods for detailed interfacial techniques developed in this project will be

characteristics, b) data for local interfacial area, incorporated into computer-aided design packages

void fraction, relative velocity and wave and disseminated to industry. Therefore, it is

propagation velocity, and c) phenomenological expected that the work will have an impact on

models for interfacial area and interfacial structural industrial practice.

changes.

Engineering Research 52 1992
Budget Number Index

Mechanical Sciences:

01-A Solid Mechanics: macroscopic aspects of elastic and plastic deformations,

and crack propagation

01-B Heat Transfer

01-C Fluid Mechanics

01-D Tribology

Control Systems and Instrumentation:

03-A Control systems, large scale systems

03-B Instrumentation for hostile environment, and NDE

03-C Intelligent systems

Engineering Data and Analysis:

06-A Thermophysical properties and processes

06-B Combustion

06-C Non-linear dynamics and engineering analysis
Budget Page

Number Number

01-A

Chaos in Fluid-Structure Systems ................................... 1

Bounds on Dynamic Plastic Deformation ............................... 2

Continuous Damage Mechanics - Critical States .......................... 2

An Investigation of the Effects of History Dependent Damage in Time Dependent

Fracture Mechanics ............................................ 2

A Micromechanical Viscoplastic Stress-Strain Model with-Grain Boundary Sliding . . 11

Chaos in Fluid-Structure Systems ................................... 12

Elastic-Plastic Fracture Analysis Emphasis on Surface Flaws ................. 15

Modeling and Analysis of Surface Cracks .............................. 25

Basic Engineering Sciences of Solids Comminution ....................... 26

Inelastic Deformation and Damage at High Temperature .................... 41

Stochastic Quadrization for Probabilistic Analysis of Large Compliant

Off-Shore Structures .......................................... 42

Stability and Stress Analyses of Surface Morphology of Elastic and

Piezoelectric M aterials .......................................... 45

Energy Changes in Transforming Solids ............................... 46

Effective Elastic Properties and Constitutive Equations for Brittle

Solids Under Compression ....................................... 50

01-B

Thermal Radiation and Conduction in Microscale Structures .................. 3

Traveling-Wave Convection in Fluid Mixtures ........................... 6

Momentum and Heat Transfer Processes in Viscoelastic Fluids ................ 18

Stability and Rupture of Thin Fluid Films on Heated Solid Surfaces ............ 32

Radiative Transfer Through an Array of Discrete Surfaces ................... 36

Radiative Transfer Through Arrays of Discrete Surfaces with Fixed Orientation .... 37

Ultimate Limits of Boiling Heat Fluxes ................................ 40

Fluid Dynamics of Double Diffusive Systems ........................... 47

Mass and Energy Coupling Effects in Multiphase Free Shear Flows ............ 51

01-C

Hydrodynamic Instabilities and Coherent Structures ....................... 1

Basic Studies of Transport Processes in Porous Media ...................... 4

Turbulence Structure and Transport Processes in Wavy Liquid Streams .......... 7

Lift and Drag Forces on Droplets and Particles in Wall-Bounded Flows ......... 11

Experiments in Turbulent Mixing .................................... 12

Two Phase Potential Flow ......................................... 13

Analytical and Experimental Study of Instabilities in Buoyancy-Driven Convection

in Porous M edia .............................................. 14
01-C

Gas-Liquid Flow in Pipelines ...................................... 17

Numerical and Physical Modelling of Two-Phase Flow Phenomena at Large

Reynolds Numbers ............................................. 18

Turbulence Theory and Reduced Hydrodynamic Description .................. 19

Two-Phase Flow Measurements by NMR ......... ... .................. 20

Lagrangian Analysis of Contaminant Dispersal in Bounded Turbulent Shear Flows . . 22

Stability and Heat Transfer in Time-Modulated Flows .................... 23

Rheological and Flow Characteristics of Dense Multiphase Slurries Employing a

Bimodal Model ............................. ................ 27

Stability Studies of Core-Annular Flows ............. ... ........... 28

Convection and Dispersion in Coarse-Packed Beds ........................ 29

The Rheology of Concentrated Suspensions ............................ 30

Effects of Capillarity of Macroscopic Flow in Porous Media ................. 32

Wave Dynamics on Falling Films and Its Effects on Heat/Mass Transfer ......... 33

Study of Interfacial Behavior in Cocurrent Gas-Liquid Flows ............... . 34

Effect of Forced and Natural Convection on Solidification of Binary Mixtures ..... 39

Interfacial Area and Interfacial Transfer in Two-Phase Flow ...... ........... 40

Microcomputer Enhanced Optical Investigation of Spreading and Evaporative

Processes in Ultra-Thin Films ..................................... 41

Particle Pressures in Fluidized Beds .................................. 44

Interfacial Area and Interfacial Transfer in Two-Phase Flow Systems ........... 52

01-D

Cryotribology: Development of Cryotribological Theories and Application to

Cryogenic Devices .......................................... ..... 25

03-A

Modeling for Process Control ...................................... 8

Integration of Redesign Methodologies for Chemical Processes ................. 8

Intelligent Control of Thermal Processes ........................... 16

Model Building, Control and Optimization of Large Scale Systems ............ 17

A General Procedure for the Synthesis of Process Flowsheets .. ........ ..... 22

Synthesis and Optimization of Integrated Chemical Processes ................ 23

Partial Control of Complex Processing Systems ......................... 30

Degenerate Four-Wave Mixing as a Diagnostic of Plasma Chemistry .......... 48

Investigation Of PACVD Protective Coating Processes Using Advanced

D iagnostic ..................... ............ ........ ...... 50

Dynamical Systems with Internal Structure: A New Approach to the Problem of

Analysis and Robust Design of a Time Varying System ................... 51

New Process Modeling, Design and Control Strategies for Energy Efficiency,

High Product Quality, and Improved Productivity in the Process Industries ..... 52
03-B

Nondestructive Evaluation of Superconductors .. ... .............. 16

Pulse Propagation in Inhomogeneous Optical Waveguides ... ............ 21

Metal Transfer in Gas Metal Arc Welding ...... .................... 23

Multivariable Control Of The Gas-Metal Arc Welding Process ............... 24

Development of Measurement Capabilities for the Thermophysical

Properties of Energy-Related Fluids ................................. 29

Quantitative Non-Destructive Evaluation of High Temperature

Superconducting M aterials ....................................... 31

Two-Phase Flow Measurements by NMR ... ...................... 43

Application of Magnetomechanical Hysteresis Modeling to Magnetic

Techniques for Monitoring Neutron Embrittlement and Biaxial Stress .......... 45

Optical Techniques for Superconductor Characterization ............ ....... 46

Advanced Diagnostics For Plasma Chemistry .............. .......... 47

03-C

Research on a Reconfigurable and Reliable Manipulators ........... ......... 9

Neural Learning Formalisms for Global Manipulator Redundancy Resolution

Problems in Unstructured Environments .......................... 18

The Use of Stereo Optical Flow Fields in the Determination of Three-Dimensional

Motion and Stereo Correspondence . .......... ......... .. 20

The Mechanics of Redundantly Driven Robotic Systems ................ .... 21

Center for Engineering Systems Advanced Research (CESAR) .. .............. 34

06-A

Three Phase System Modelling .................................. 14

In-Flight Measurement of the Temperature of Small, High Velocity Particles .... 14

Modeling of Thermal Plasma Processes ..... ........................... 15

Bioprocess Engineering Research for Energy Applications .................. 35

Experimental and Theoretical Studies of Multicomponent Vapor Condensation ..... 38

Transport Properties Of Disordered Porous Media From The Microstructure ....... 39

06-B

Experimental and Theoretical Study of Fuel Droplets Subject to Straining Flow .... 5

Experiments on the Gas Dynamics of the HVOF Thermal Spray Process ......... 37

Mechanisms and Enhancements of Flame Stabilization ..................... 38

Mixing and Phase Change During Combustion ........................... 44

Structure of Inverse Diffusion Flames in Supercritical Fuel/Water Mixtures ..... 44
06-C

Self-Generated Stochastic Heating in an RF Discharge ..................... 3

Wave Turbulence and Self-Localization in Continuous Media ................ 4

Nonperiodic, Broadband Signals: Signal Processing in Chaos ................. 4

Noisy Nonlinear Systems ........................................ 5

Knot Invariants and the Thermodynamics of Lattice Gas Automata ............. 6

Formation of Three-Dimensional Singularities, Regularization Procedures

and Markovian-Multifractal Description of Turbulent Flows ................ 6

Bifurcations and Patterns in Nonlinear Dissipative Systems .................. 7

Finite-Time Thermodynamics and Effective Energy Use .................... 10

Fundamentals and Techniques of Nonimaging Optics ...................... 10

Mixing and Settling in Continuous Metal Production ....................... 13

Studies in Nonlinear Dynamics ................................. .... 19

Mathematical Models of Hysteresis ................................... 20

M acrostatistical Hydrodynamics ..................................... 27

Thermal Plasma Processing of Materials ............................... 28

Department of Energy Integrated Manufacturing Fellowship Program ........... 28

Low Resistivity Ohmic Contacts Between Semiconductors and High-Tc

Superconductors .............................................. 30

Studies in Premixed Combustion .................................... 31

Mixing of Immiscible Fluids in Chaotic Flows and Related Issues ............. 33

Stability and Dynamics of Spatio-Temporal Structures ..................... 33

Turbulence and Spatio-Temporal Chaos .............................. 35

The Evolution of a Hele-Shaw Interface and Related Problems in Dendritic

Crystal Growth ............................................... 36

Active Control of Convection ....................................... 37

Radiative Interactions with Micromachined Surfaces:

Spectral Angular Polarized Emittance ............................... 37

The Continuum Modeling of Two-Phase Systems ........................ 41

Flux Flow, Pinning, and Resistive Behavior in Superconducting Networks ........ 42

Coherence Effects in Radiative Energy Transfer .......................... 43

Some Basic Research Problems Related to Energy ........................ 43

Thermodynamics and Stochastic Theory of Hydrodynamics and Power Producing

Processes .................. ................................. 48

Investigation of Transitions From Order to Chaos in Dynamical Systems ......... 49

The Behavior of Matter Under Nonequilibrium Conditions: Fundamental Aspects

and A pplications .............................................. 49

Complex Temporal and Spatial Patterns in Nonequilibrium Systems ............ 50
Principal Investigators

H. Abarbanel 4 E. Fukushima 20 C. Law 38 W. Roman 50

J. Achenbach 31 H. Gao 45 P. Libby 5 J. Ross 48

A. Acrivos 30 J. Georgiadis 14 A. Lichtenberg 3 M. Sablik 45

G. Ahlers 7 B. Ghosh 51 M. Lieberman 3 S. Schladow 47

S. Altobelli 20 R. Givler 43 K. Lindenberg 5 G. Schmidt 49

G. Andrews 14 A. Graham 27 R. Littlejohn 19 C. Scott 35

J. Balint 22 1. Grossmann 8 W. Lloyd 15 J. Sengers 29

S. Banerjee 7 T. Hanratty 17 M. Malone 22 G. Settles 37

S. Bankoff 32 D. Hardt 24 R. Mann 34 R. Shinnar 30

J. Barhen 18 J. Hartnett 18 I. Mayergoyz 20 G. Sivashinsky 31

D. Barnett 46 S. Hay 50 F. McClintock 25 H. Smartt 16

T. Basar 17 W. Haynes 29 M. McCready 34 P. Spanos 42

H. Bau 37 F. Hayot 35 J. McLaughlin 11 R. Steeper 44

A. Bergles 40 G. Herrmann 46 C. Menyuk 21 R. Street 47

P. Bernard 22 G. Hetsroni 7 D. Meyer 6 C. Surko 6

R. Berry 10 F. Incropera 39 M. Miksis 32 H. Swinney 50

L. Biegler 8 M. Ishii 40 M. Moldover 29 S. Tanveer 36

H. Brenner 27 Y. Iwasa 25 L. Mondy 27 S. Teitel 42

F. Brust, Jr. 2 C. Jayaprakash 35 F. Moon 12 K. Telschow 16

C. Campbell 44 M. Jensen 40 M. Morari 8 C. Thompson 23

D. Cannell 7 J. Johnson 16 J. Moreland 30 G. Thompson 8

M. Cappelli 47 M. Jones 29 T. Mulcahy 1 C.-L. Tien 3

A. Caprihan 20 E. Jordan 11 R. Nassimbene 29 S. Torquato 39

I. Catton 4 D. Joseph 28 E. Novikov 6 T. Troutt 51

C. Chang 15 M. Kachanov 50 F. Otter 50 L. Tsai 21

H.-C. Chang 33 T. Kanade 9 J. Ottino 33 K. Walker 11

S. Chen 1 A. Kaufman 19 D. Parks 25 J. Wallace 22

E. Cohen 43 R. Kayser 29 C. Peterson 26 G. Wallis 13

S. Davis 32 A. Kerstein 44 T. Petrosky 49 Z. Warhaft 12

J. Douglas 22 P. Khosla 9 E. Pfender 28 P. Wayner, Jr. 41

D. Drew 41 G. Kino 46 F. Pin 34 J. Welty 36

M. Drost 37 G. Kojasoy 52 I. Prigogine 49 A. Westerberg 8

J. Duncan 20 P. Kokotovic 17 R. Probstein 27 G. Wilemski 38

T. Eagar 23 J. Koseff 47 A. Prosperetti 18 F. Williams 5

A. Eckbreth 50 R. Kraichnan 19 S. Putterman 4 R Winston 10

J. Ekin 30 D. Krajcinovic 2 J. Ramshaw 15 E. Wolf 43

J. Epstein 15 E. Krempl 41 W. Ray 52 J. Wolfe 29

L Evans 23 C. Kruger 47 W. Reuter 15 C. Youngdahl 2

J. Fincke 14 B. Kuhn 28 H. Richter 13 R. Zare 48

A. Frenkel 1 R. Lahey, Jr. 41 H. Riecke 33

M. Frish 38 J. Lang 23 I. Rinard 30

Engineering Research 1992
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