bluuebunny/crossref_metadata_2025 huggingface dataset:
Transition of Mixtures of Polymers in a Dilute Aqueous Solution
Authors: White W. D. , McEligot D. M.
Published: November 2010

Data are presented for the flow of deionized water solutions of linear, unbranched polymers—Separan AP-30, Polyox WSR-35 and Polyox WSR-301, and mixtures of the latter two in a 0.0235 in. tube. The Reynolds numbers vary from about 1200 to about 12,000. Measurements were made at 4 deg C and near room temperature. Occurrence of transition is confirmed by oscillograph traces and pressure ratio calculations in addition to the usual “break” on a friction factor-Reynolds number graph. From the calibration data, it appears that for small tubes there is a critical parameter, such as molecular weight or polymer length, below which transition occurs as for water, but above which the transition Reynolds number depends on polymer concentration. The low and high polymers were mixed to vary molecular weight distribution of samples. It was found that the higher molecular weight polymer dominates the transition process, but in the turbulent regime the effects are roughly additive.
The Gaseous Squeeze-Film at Moderately Large Squeeze Numbers
Authors: Pan C. H. T.
Published: November 2010

The asymptotic analysis of the gaseous squeeze-film bearing has been extended to obtain 0 {σ−1/2} effects in accordance with the isothermal gas lubrication theory and the method of singular perturbation. 0 {σ−1/2} corrections are identified to contain not only edge effects (inner problem) but also edge-interior interactions which are analogous to the boundary layer displacement effects in aerodynamics. The latter features can further be recognized to be related to mean-gap taper, squeeze taper, and cross-edge sliding. These results are discussed from the point of view of “global bearing properties” including the temporal mean as well as the in-phase and quadrature synchronous components of the fluid film force and moment. The edge effects are presented in terms of universal functions which can be used directly as corrections in the global properties. The edge-interior interactions must be determined by solving the asymptotic p.d.e. with boundary condition also expressed in terms of universal functions. Formulations applicable to cylindrical, conical, and spherical bearing geometries are outlined. Illustrative numerical examples are provided. Conditions affecting the validity of the isothermal gas lubrication theory (neglecting inertia effects) as related to the magnitude of the squeeze number are discussed.
Wear of Small Orifices by Streaming Current Driven Corrosion
Authors: Beck T. R. , Mahaffey D. W. , Olsen J. H.
Published: November 2010

Wear on the upstream side of small metal orifices subject to large pressure drops (3000 psi) in phosphate ester base hydraulic fluids has been found to be the result of an electrochemical corrosion driven by a streaming current. A calculation for the current produced by the flowing fluid is described. Results of the calculation and of experimental work are given as evidence in support of the proposed wear mechanism. A large variation of wall shear stress along the metal surface is found to be necessary for the wear.
Effects of Applied Acoustic Fields on Attached Jet Flows
Authors: Rockwell Donald O. , Toda Kenji
Published: November 2010

The effects of application of sound of a spectrum of frequencies and amplitudes to bounded attached jets of a range of Reynolds numbers flowing over surfaces of various radii of curvature have been examined using hot-wire anemometry, smoke visualization, and tuft-deflection techniques. Frequencies of sound to which the jet is sensitive, results of changes in sound amplitude at a given frequency, and the growth of the effects of applied sound with arc length from the nozzle exit were investigated to provide some qualitative design criteria for controlling the sensitivity of flueric elements to externally applied sound. Frequencies of sound which are related to the jet nozzle resonance characteristics have the most severe effect on the attached jet. For a given applied frequency, the flow field of the jet can be altered for a much wider range of jet Reynolds number at higher amplitudes of applied sound than at relatively low amplitudes of applied sound. Four Reynolds numbers regimes can be established to describe the behavior of the attached jet with applied sound, Frequency- and amplitude-dependent jumps in angle of detachment of the jet are attainable in the first two regimes, and deflections of the jet proportional to the applied frequency and amplitude are attainable in the third and fourth regimes.
Fracture Toughness of ASTM A533 Grade B Class 1 Heavy Section Submerged Arc Weldments
Authors: Shabbits W. O. , Pryle W. H. , Wessel E. T.
Published: November 2010

Fracture toughness data are presented for two ASTM A533 Grade B Class 1, 12-in-thick plate submerged arc process weldments. These data were generated in accordance with current ASTM recommended toughness testing procedures using compact tension specimens up to 8 in. thick. The toughness (KIc) properties show a strong temperature dependence resulting in rapidly increasing toughness with increasing temperature. Each of the weld deposit materials and also some limited heat-affected-zone data revealed toughness properties comparable or superior to ASTM A533 Grade B Class 1 plate material. Pertinent data relating to the weld parameters and composition, as well as the conventional tensile and Charpy V notch data are also given. For these weldment materials, the high toughness (KIc) properties found provide excellent reliability against brittle fracture in heavy section pressure vessel applications.
The Effect of Droplet Solidification Upon Two-Phase Nozzle Flow
Authors: Shankar P. N.
Published: November 2010

The handling of changes of phase in perturbation treatments of two-phase nozzle flow requires particular care. Droplet solidification, the phase change considered here, introduces two novel complications in a perturbation treatment of the problem. First, the boundaries of the zone of solidification are shifted by first-order corrections to the droplet temperature and liquid fraction, and these shifts introduce, in turn, further first-order corrections. This feedback effect is of particular interest and the magnitudes of the corrections are very significant. Second, a singular perturbation procedure is required to handle the problem at points where solidification first starts and where it is completed. The techniques presented here should be applicable to other problems involving phase change in two-phase flow.
Some Aspects of Gas-Solid Suspension Turbulence
Authors: Baw P. S. H. , Peskin R. L.
Published: November 2010

An analysis is given for the apparent particle energy spectrum function in addition to the analysis of the effect of particles on the fluid energy spectrum in a turbulent gas-solid suspension flow. The analysis assumes that the problem of the motion of a continuous medium containing solid particles can be treated as two interacting continuous media, namely, the gas—and the solid—phase. The results obtained show that upon introduction of the particles the energy density of the fluid decreases more rapidly than for the case of pure fluid as wave number increases.
Fatigue Strength Optimization of Bonded Joints
Authors: Hamel D. R. , Korbacher G. K. , Smith D. M.
Published: November 2010

The possibility of improving the fatigue strength of bonded double strap joints by reducing the stress concentration, inherently encountered at the conventional square (90 deg) strap edge, was studied. A 10 deg bevel on the strap edges was used for this purpose and joint specimens of both types were fatigue tested. The test data were plotted as S-N curves and compared with those of plain metal specimens. The metal employed was 2024-T3 clad aluminum alloy and the adhesive, FM-123-2. The results indicate that stress concentrations on square strap edges are in practice, due to plastic relaxation, much lower than theory predicts and that, therefore, the resulting but limited gains in fatigue strength due to bevelling of the strap edges doesn’t seem worth the extra effort.
The Yield Condition and Flow Rule for a Metal Subjected to Finite Elastic Volume Change
Authors: Haddow J. B. , Hrudey T. M.
Published: November 2010

A theory for elastic-plastic deformation with finite elastic strain is outlined. The results of this theory are specialized to consider a metal subjected to high hydrostatic pressure which produces finite elastic volume change. Drucker’s postulate is used to obtain the form of the yield condition and the associated plastic flow rule.
Incompressible Turbulent Flow in a Permeable-Walled Duct
Authors: Sparrow E. M. , Jonsson V. K. , Beavers G. S. , Owen R. G.
Published: November 2010

An analysis is made of fully developed turbulent flow in a parallel-plate channel having one porous bounding wall. A velocity slip model is employed to characterize the boundary condition at the porous surface. The turbulent transport processes in the channel are represented via the Prandtl mixing length concept in conjunction with a modified form of the Van Driest damping factor. Numerical results are obtained for Reynolds numbers ranging from 5000 to 200,000 and for a wide range of values of a dimensionless slip grouping. The results show that velocity slip at the porous surface brings about a reduction in the friction factor, the extent of the reduction being accentuated with increasing Reynolds number. The velocity slip also causes a skewing of the velocity profiles, such that the location of the maximum velocity is shifted toward the porous wall.
A Method for Measuring Aerodynamic Pressure Below Wave Crests
Authors: Kordyban E.
Published: November 2010

This paper describes a submersible pressure probe, which permits the measurement of the pressure near the surface of a water wave, even in the regions below the crest. The probe is based on the principle that the liquid entry into a cavity through a small hole is impeded by surface tension. Normally, however, there is liquid membrane formed over the hole upon withdrawal from water, and this was solved by selection of proper material. The methods of testing the probe and some measurements obtained with it are also presented in this paper.
Turbulent Flow in Smooth and Rough Pipes
Authors: Townes H. W. , Gow J. L. , Powe R. E. , Weber N.
Published: November 2010

Fully developed turbulent flow in both smooth and rough-walled pipes is investigated for Reynolds numbers from 30,000 to 480,000. The values of mean velocity, root-mean-square values of the fluctuating velocity components, and cross-correlation values of the fluctuating velocities are presented for flow in a smooth pipe and two sand-roughened pipes, R/ε = 208 and R/ε = 26.4. The quantity R/ε is the ratio of the actual pipe radius to the average sand particle size. The experimental measurements for flow in smooth pipes are in good agreement with those of previous investigations throughout the Reynolds number range considered. Several of the rough pipe turbulence quantities show substantial deviations from the corresponding smooth pipe quantities. For rough pipes, the measured uv cross-correlation values approach those predicted empirically from the Reynolds equations for fully developed, axisymmetric flow as the flow approaches the hydraulically smooth case. However, as the Reynolds number is increased and the flow proceeds through the transition region from smooth to fully rough flow and to the fully rough flow region, the values of the uv cross correlation in rough pipes are significantly lower than the predicted values. This difference between predicted and measured data becomes more pronounced as the Reynolds number is further increased and the flow becomes fully rough. The difference between measured and predicted uv values, and other differences between smooth and rough pipe results, suggests that the accepted reduction of the Reynolds equations for flow in smooth pipes is not valid for flow in rough pipes. Thus, the Reynolds equations are re-examined for flow in rough pipes, and it is shown that these equations can be satisfied by the experimental data if secondary flows and angular variations in the mean velocity are postulated.
Finite-Element Analysis of Pressure Vessels
Authors: Davis R. L. , Keith H. Dean
Published: November 2010

The finite-element technique has been applied in the analysis of a variety of pressure vessel problems. The example problems described in this paper suggest that the finite-element method is perhaps the most suitable means currently available for obtaining quick and accurate solutions for real-life pressure vessel problems. Finite-element programs can be used by the practicing engineer. Companion programs are available that can be used to check the input data and graphically display both the input and output data.
A Theoretical Model for Nonseparated Mixing of a Confined Jet
Authors: Razinsky E. , Brighton J. A.
Published: November 2010

A model and procedure for calculating turbulent mixing of a confined jet is presented. The flow consists of a high velocity jet which is directed into a constant diameter duct, where it mixes with a concentric, low velocity stream. The flow model which includes the wall boundary layer covers the entire flow development from the mixing tube entrance to the start of fully developed flow conditions. The calculated results are presented for a range of flow conditions and are compared with the experimental results of a previous paper by the same authors. It was found that including the boundary layer, as part of the model, gave results which were significantly different and in better agreement with experiment for small and moderate velocity ratios.
Improvement of Hysteresis Characteristics of Francis Pump-Turbines When Operated as Turbine
Authors: Yamabe M.
Published: November 2010

The turbine hysteresis characteristics in Francis pump-turbines when operated as turbine were reported in the previous paper [1]. In the present report the characteristics of inner flow of runners will be observed and at the same time the effect given by the entrance angle of runner vanes and the sweepback at the entrance of runner vanes to the performance of pump-turbine will be studied. As a result, the enlargement of the sweep-back at the entrance of runner vanes is to be proved as a desirable remedy to hysteresis characteristics of Francis pump-turbines.
Actuator Disk Theory for Incompressible Highly Rotating Flows
Authors: Oates G. C.
Published: November 2010

A solution has been obtained for a stator-rotor pair operating in an annulus with constant hub and tip radii. The stator and rotor are represented as actuator discs, and perfect fluid flow is assumed. The solutions are exact within these limitations, no linearization being required. The forms of blade loadings considered allow the introduction of large vorticity by either the rotor or stator. As a result, the rotor may be a “nonconstant-work” row. The solutions obtained are of summational form, but many of the summations are obtained in closed form, the resultant formulas allowing rapid calculation of desired examples. An example numerical result is included.
An Optimum Design for Pressure Sensing Machined Diaphragms
Authors: Motherway J. E.
Published: November 2010

A means of increasing the useful range of pressure sensing diaphragms is developed. This is done by considering certain variable thickness plates as potential diaphragms and attempting to maximize deflection without causing other performance characteristics to differ appreciably from those of a uniform thickness plate. A thickness variation which is simple to manufacture is found and optimum geometric parameters are determined. Results are presented in the form of a series of equations which are convenient for use by the instrument designer.
Equipment for the Experimental Determination of Thermal Properties of Fluids at Elevated Pressures
Authors: Bishnoi P. R. , Robinson D. B.
Published: November 2010

The available methods for determining the thermal properties of compressible fluids by flow calorimetry are reviewed and an analysis is given for the method of determining heat capacity ratios by passing the fluid at low and high pressures through a heat exchanger. The design of the heat exchanger calorimeter and its associated equipment are described in detail. The performance of the equipment in determining the heat capacities of nitrogen was evaluated at temperatures of 60.2, 75.7, and 150.4 deg C and at pressures up to 2200 psi. The results were compared where possible with those of other workers. Agreement was within about ±0.5 percent which is the anticipated accuracy of the method.
On the Numerical Solution of Two-Dimensional, Laminar Compressible Flows With Imbedded Shock Waves
Authors: Goodrich W. D. , Lamb J. P. , Bertin J. J.
Published: November 2010

The complete, time-dependent Navier-Stokes equations are expressed in conservation form and solved by employing an explicit finite difference numerical technique which incorporates artificial viscosity terms of the form first suggested by Rusanov for numerical stability in the vicinity of shock waves. Surface boundary conditions are developed in a consistent and unique manner through the use of a physically oriented extrapolation procedure. From numerical experimentation an extended range for the explicit stability parameter is established. Also employed is an additional convergence parameter which relates incremental spatial steps. Convergence of the transient solution to a steady state flow was obtained after 400 to 500 time steps. Sample solutions are presented for supersonic flow of air over the leading edge of a slightly blunted flat plate, past a backward facing step, and in the near wake of a blunt trailing edge. Free-stream Mach numbers from 2 to 10 are included in the sample computations.
Ocular Tonometry Through Sonic Excitation and Laser Doppler Velocimetry
Authors: Hamelink J. M. , Cloud G. L.
Published: November 2010

Glaucoma is an insidious eye disease which must be detected in its early stages for there to be successful treatment. Primary detection of glaucoma and evaluation of therapy have depended upon tonometric methods which require applanation of the cornea. A new method of IOP determination which is noncontacting and nonapplanating has been devised. The technique utilizes low-level sonic excitation of the eye and detection of the resulting cornea vibrations by laser Doppler velocimetry. Studies of a laboratory model and of freshly excised lambs’ eyes show that there is a measurable shift of corneal response frequencies with changing IOP. An empirical relationship between IOP and response frequency for in-vitro lamb’s eyes was found to be f = 233.65 + 6.9 (In IOP in mm Hg)1/2. Standard deviation of all data obtained in the physiological range of IOP’s was approximately 2.5 mm Hg for the experiment which was devised to test the idea. The results provide the basis of design for a procedure to be used in vivo.
Fluid Mechanics of Longitudinal Contractions in the Small Intestine
Authors: Melville J. G. , Denli N.
Published: November 2010

Longitudinal contractions in the duodenum are shown to exit experimentally. A low Reynolds number model of flows induced by propagating longitudinal contractions is presented for circular conduits. Particle trajectories and time lines are shown to elucidate the flowfields. Longitudinal motor activity is shown to have the capability of satisfying the mixing function of the small intestine and to be a possible contributor of retrograde flow.
On the Feasibility of Obtaining Three-Dimensional Information From Thermographic Measurements
Authors: Chen M. M. , Pedersen C. O. , Chato J. C.
Published: November 2010

Despite its many advantages, thermography as a medical diagnostic tool has two basic limitations: 1 its images are indirect manifestations of interior thermal structure and hence do not yield explicit spatial information; 2 it is fundamentally two-dimensional. It is shown in the present paper that the three-dimensional variations of the temperature-dependent volume heat source, often called the blood perfusion term in the bio-heat equation, can be extracted from time dependent thermographic observations. On the other hand, spatial variations of the metabolic healing term cannot be determined from a similar procedure. Numerical experiments are performed to explore the sensitivity of the technique in determining the magnitude and location of a hypothetical lesion. Limitations of the technique in terms of the thermal penetration depth and signal-to-noise ratio are also examined.
Some Sufficient and Some Necessary Conditions for the Stability of Multivariable Systems
Authors: Shieh Leang S. , Shih Chao D. , Yates R. E.
Published: November 2010

Some sufficient and some necessary conditions for the stability of a class of multivariable systems represented by matrix polynomials are derived. A new linear block transformation is also established for transforming an observable block companion form to the block Schwarz form.
Coupled Vertical-Lateral Dynamics of a Pneumatic Tired Vehicle: Part II—Simulated Versus Experimental Data
Authors: Nathoo N. S. , Healey A. J.
Published: November 2010

The vertical and lateral acceleration response of an automobile to roadway roughness inputs was simulated using a ten degree-of-freedom mathematical model. The simulated response compared favorably with that obtained experimentally in terms of their power spectral density functions and root mean squared values in the 0.1–10 Hz frequency range. Furthermore, within the context of ride quality, a sensitivity study was conducted to determine the effect of variations in the suspension damping ratio, anti-roll bar stiffness and lateral “pneumatic” stiffness on vehicle response variables. The indication is that a trade-off exists between the reduction in lateral and roll motions due to an increase in suspension damping and the resulting increase in the higher frequency components in the vertical acceleration. The model that has been developed is well suited for performing design trade-off analysis.
Harmonic Analysis of Dynamic Systems With Nonsymmetric Nonlinearities
Authors: Spanos P-T. D. , Iwan W. D.
Published: November 2010

The generalized method of equivalent linearization is modified to be applicable for multi-degree-of-freedom dynamic systems with nonsymmetric nonlinearities subjected to harmonic monofrequency excitation. Readily applicable formulas are given for the construction of the equivalent linear systems related to a class of systems commonly encountered in engineering applications. As an example of its application, the proposed method is used to generate an approximate steady-state solution for a simple vehicle system. The accuracy of the approximate solutions is determined.
Two-Dimensional Dynamics of Tracked Ram Air Cushion Vehicles With Fixed and Variable Winglets
Authors: Sweet L. M. , Curtiss H. C. , Luhrs R. A.
Published: November 2010

A linearized model of the pitch-heave dynamics of a Tracked Ram Air Cushion Vehicle is presented. This model is based on aerodynamic theory which has been verified by wind tunnel and towed model experiments. The vehicle is assumed to be equipped with two controls which can be configured to provide various suspension system characteristics. The ride quality and dynamic motions of the fixed winglet vehicle moving at 330 km/hr over a guideway described by roughness characteristics typical of highways is examined in terms of the rms values of the vertical acceleration in the foremost and rearmost seats in the passenger cabin and the gap variations at the leading and trailing edges of the vehicle. The improvement in ride quality and dynamic behavior which can be obtained by passive and active suspension systems is examined and discussed. Optimal regulator theory is employed to design the active suspension system. The predicted rms values of the vertical acceleration in the one-third octave frequency bands are compared with the vertical ISO Specifications. It is shown that marked improvements in the ride quality can be obtained with either the passive or active suspension systems.
Evolutions in Automatic Control
Authors: Auslander D. M.
Published: November 2010

This paper is an exploration of automatic control history from a mechanical engineering perspective. Developments in the major fields of automatic control are discussed as is the catalytic influence of professional societies such as ASME’s Automatic Control Division.
A Computer-Oriented, Parameter-Space Approach to the Synthesis of Nonlinear Control Systems
Authors: Garg D. P.
Published: November 2010

A systematic synthesis procedure is developed for ensuring an absence of limit cycles in nonlinear systems. Compensator parameter plots, subject to specified constraints, are generated in parameter planes. These plots can be combined to yield design surfaces. The proposed approach is oriented for digital computation but can be adapted easily to a paper and pencil equivalent. The procedure is illustrated by two design examples.
Cavitation Effects in On-Off Controlled Hydraulic Servos
Authors: McCloy D.
Published: November 2010

The paper presents an analytical study of the response of a loaded hydraulic cylinder to step inputs. The inputs considered are typical of those encountered in on-off servos using closed center, three position valves. Cavity formation and pressure peaks are discussed and formulated. The effect of cylinder position on system natural frequency is evaluated.
Design of Vortex Fluid Amplifiers With Asymmetrical Flow Fields
Authors: Lawley T. J. , Price D. C.
Published: November 2010

Variation of geometric parameters, including supply area, control area, chamber length, and outlet diameter, of a large scale, modular design vortex fluid amplifier with single supply and control jets, has confirmed and extended a previously published design method, developed for vortex amplifiers with symmetric flow fields. This allows application of the method to devices which are more representative of practical, production type components.
Bits of Recorder History
Authors: Williams A. J.
Published: November 2010

The bits of history are in the recorder/controller field and each bit of history is strictly from the author’s limited view like the prairie dog’s view of the prairie. Although some of the bits pertain to work which had subsequent impact in the field, several of the bits have been selected for inclusion simply because the author has a vivid recollection (in each case) of solving a problem, which he then thought was important.
Turn-ON and Turn-OFF Times for a Laminar Jet
Authors: Abramovich S. , Solan A.
Published: November 2010

Experimental results of the speed of travel of a disturbance in front of suddenly switched-on and switched-off submerged laminar jets are presented. The results show that the time lag for a switched-off jet is approximately one half the time required for a particle moving in front of a switched on jet to reach a certain distance from the jet nozzle. The time lags for an instantaneous change in the jet intensity is approximately the same as that for switching the whole jet on and off. These experimental data can be used to calculate the switching times of turbulence amplifiers.
Some Sufficiency Conditions for Pareto-Optimal Control
Authors: Leitmann G. , Schmitendorf W.
Published: November 2010

We consider the optimal control problem with vector-valued criterion (including cooperative games) and seek Pareto-optimal (noninferior) solutions. Scalarization results, together with modified sufficiency theorems from optimal control theory, are used to deduce sufficient conditions for Pareto-optimality. The utilization of these conditions is illustrated by various examples.
Control Concepts for Pneumatic-Tube Vehicles
Authors: Wright D. , White K. P.
Published: November 2010

The pneumatic-tube transport system, its operation, and its conceptual development as a high-speed-ground-transportation alternative are discussed briefly. Schemata for control of passive and nonpassive tube vehicles are proposed. System simulations employing a Fanno-flow model and each of the control schemata are outlined. Results contrasting controlled and uncontrolled system operation are presented as plots of the vehicle’s velocity and acceleration versus the vehicle’s position in the tube. Results evidence the infeasibility of existing, passive vehicle concepts.
A Note on Optimal Open-Loop and Closed-Loop Control
Authors: Leitmann G.
Published: November 2010

Optimal open-loop and closed-loop controls are defined in a consistent fashion. It is shown that under certain conditions an optimal closed-loop control generates an optimal open-loop one and that optimal closed-loop control can be synthesized from optimal open-loop one.
State of the Art of Nuclear Reactor Instrument Automation
Authors: Taeschner M. , Gariod R.
Published: November 2010

Due to its complexity, nuclear reactor instrument automation is a challenge to engineers. High investment and running costs of a nuclear research reactor imply the use of advanced equipment and concepts for instrument automation when striving for high performance, reliability, and operational convenience under budgetary pressure. The article describes a successfully operating instrument automation system stressing the important underlying concepts trying to avoid too much details on specific hardware which is dependent on the time when one must order things.
Optimum Response Simulation of Multidegree Systems by Pulse Excitation
Authors: Masri S. F. , Bekey G. A. , Safford F. B.
Published: November 2010

A computer algorithm is presented for the optimum selection of a series or train of force pulses for application to a continuous system. The optimized pulse train generates oscillations in a system to match within specified error bounds the responses which would be produced by a continuous loading of arbitrary nature such as earthquake excitation. This computationally efficient algorithm is applied to several examples including a model of a physical system. It is shown that it is feasible to adequately simulate the motion of a complicated system by using appropriate force pulse trains.
On State Equation Descriptions of Linear Differential Systems
Authors: Godbout L. F. , Jordan D.
Published: November 2010

A completely general algebraic method for converting a set of linear differential equations that describe a multivariable system to the standard state equation model is considered. The computational procedure is developed in a straightforward manner so that the algorithm can be easily implemented on a digital computer. Several examples are presented to illustrate all phases of the method. A PL/I program has been developed by the authors for use on the IBM 360 computer.
Parameter Optimization for Linear Quadratic Differential Games
Authors: Leondes C. T. , Siu T. K.
Published: November 2010

How should the minimizing player choose the values of certain parameters, if he wants to further optimize his payoff at the maximizing player’s expense? Hence what would be the greatest lower bound for the maximizing player’s payoff? To answer these questions, necessary conditions for parameter optimization for linear quadratic differential games will be derived. Iterative numerical techniques for determining optimal parameters will be developed. Search techniques which will locate a “small” region of uncertainty in which the optimal parameter must lie will also be discussed.
Coordination Concepts in Multilevel Hierarchical Differential Games
Authors: Jumarie Guy
Published: November 2010

This paper presents possible extensions of the usual differential game theory to the case where the players, say the supremal players do not completely govern the plant, but control it only via infimal players who have their own pay-off functions. One assumes that the internal structure of the game is given in the sense that the supremal players cannot define arbitrary decompositions for the system. One further assumes that these supremal players have given programming terminal objectives which they desire to attain. In this framework, the supremal players can only select suitable functions, which are the coordination controls, to coordinate the system for the best. It follows that the problem so defined is simultaneously an optimum control problem and a programming one. The direct coordination mode, the open-loop indirect coordination mode and the closed-loop indirect coordination mode are defined and are mainly based upon a direct reference to the overall system, together with a two-level optimization process. The explicit equations are given in the important case where the comparison criterion is defined in the form of an Euclidean norm, and an illustrative example is solved. This approach would be interesting to apply to the problem of learning and self-learning in optimum control systems for instance, via gradient techniques.
A Kinetic Hydraulic System for High Energy Rate Metal Forming
Authors: Larson V. H.
Published: November 2010

A high energy rate metal forming concept is described that uses energy from a high velocity free piston impacting on a liquid. The piston is driven by compressed air. The characteristics of the energy transfer and the pressure buildup are analyzed for a limiting case. A basic typical system design is presented. Schematic diagrams and curves illustrating limiting pressure rise and other characteristics of a typical system are presented.
Performance of an Orienting Device Employed in Vibratory Bowl Feeders
Authors: Boothroyd G. , Murch L. E.
Published: November 2010

A statistical analysis of the performance of a vee cutout orienting device used in a vibratory bowl feeder is presented. The results of experimental tests are described and compared with the analysis. From the information thus obtained it is possible to design and build such a device without the need for trial and error procedures and to obtain 100 percent efficiency.
An Iterative Method for Analyzing Oscillating Cam Follower Motion
Authors: Rahman Z. U. , Bussell W. H.
Published: November 2010

This paper describes a method of analyzing the kinematic characteristics of cams, with profiles represented by an eight-term Fourier series and with oscillating-type followers. Two kinds of cam follower systems, viz., roller follower and flat-face follower systems, are used. In general the method applies to any cam whose profile can be expressed in terms of its radius being a function of the rotation angle [r = f(θ)].
A Philosophy of Industrial Air Pollution Control
Authors: Lund Herbert F.
Published: November 2010

It is time we settled down to a sensible, practical approach to solving the industrial air pollution problem. That is the goal of this paper: to take the sensationalism out and replace it with a sensible evaluation of the situation. The major points covered are 1 a brief review of historical facts, 2 an analysis of present conditions around the world, 3 what is industry’s responsibility, 4 a comparison of legislative procedures and their enforcement effectiveness, 5 the impact of air pollution control costs on worldwide markets, 6 suggestions for solutions.
Plastic Flow at the Chip-Tool Interface During Hot Machining
Authors: Bhattacharyya B. , Scrutton R. F.
Published: November 2010

The plastic flow of metal adjacent to the chip-tool interface when machining heated workpieces is examined theoretically. It is shown that all metallic workpiece materials possess an optimum machining temperature which is dependent on the physical properties of the material. The temperature distribution in the plastic layer in the presence of an electric current normal to the interface is considered in relation to the general plastic flow of metals accompanied by Joule heating.
A Photoelastic Study of Stress Distribution During Orthogonal Cutting—Part 1: Workpiece Stress Distribution
Authors: Ramalingam S. , Lehn L. L.
Published: November 2010

This paper examines the stress distribution in the workpiece as a function of the cutting parameters associated with orthogonal cutting. It is shown that the state of stress which prevails in the workpiece during orthogonal cutting with a tool having a rake angle α, is equivalent to that which will prevail in a semi-infinite plate when a line load is applied to its edge in tension at an angle complementary to the rake angle, measured from the plate edge outer normal in the counterclockwise direction. The effect of this stress field on the surface damage accompanying metal cutting is discussed.
A Study of Plunge (or Form) Machining of Low-Carbon Resulfurized Steel on a Multispindle Automatic Screw Machine: Part 2—Influence of Speed, Feed, and Duration of Cutting on Worn Tool Geometry
Authors: Tipnis V. A. , Joseph R. A.
Published: November 2010

During the plunge-machining experiments described in Part 1, the crater and wearland profiles were obtained on plunge-cutting tools at five intervals in each of the fifty 4600-piece runs. The objective was to understand how worn tool profiles change during prolonged plunge machining of low-carbon resulfurized steels and how these changes in a worn profile affect surface finish and dimensional tolerance. First, mathematical models were developed to convert the measurements taken from worn tool profiles into tool wear parameters such as crater length, crater depth, crater curvature, BUE height, wearland, effective rake angle, and the deepest point in the crater. Second, the effect of changes in speed, feed, and of cutting duration on the tool wear parameters was studied. Finally, an effort was made to establish empirical relationships between wear parameters and machining performance. Some of the results of this investigation are: (a) For each combination of speed and feed there exists a worn tool geometry (steady state) which sets in after the initial transient wear and which lasts during the remainder of the run except at the end when rapid deterioration takes place. (b) The steady-state geometry can be described by the effective rake angle, crater curvature, wearland, BUE height and projection, and the distance to the deepest point in the crater from the highest point on BUE. (c) The surface finish in plunge machining depends on BUE height. BUE nonuniformity, and the grooves on the worn tool. (d) The wear parameters describing the worn tool geometries were more sensitive to changes in feed than to changes in speed. With feed, an optimum was observed around 0.0015 ipr where wearland, crater depth, and effective rake angle were minimum and crater radius was maximum. The results presented in Parts 1 and 2 show that plunge machining is markedly different from single-point turning in its response to changes in speed, feed, depth of cut, coolant, and workpiece materials.
Plasma Treatment of Railway Rails to Improve Traction
Authors: Gifford F. E. , Yoshino R. T.
Published: November 2010

Plasma torch treatments of track rails to improve locomotive wheel traction were investigated as a potential substitute for rail sanding. Rolling friction tests were conducted under simulated rail-wheel load conditions at about 200,000 psi contact stress. Although traction was improved significantly in laboratory tests, total power required to significantly improve the coefficient of friction for a diesel electric operation at low speeds appears excessive. Power required at 80 mph is prohibitive. Moreover, safety, maintenance, and mechanical aspects require a considerable amount of further development before such an application can be considered possible on American railroads.
Analysis of the Chisel Edge and the Effect of the d-Theta Relationship on Drill Point Geometry
Authors: Fujii S. , DeVries M. F. , Wu S. M.
Published: November 2010

Following the investigation of drill point geometry previously reported [1, 2], the chisel edge profile and the chisel edge angle are analyzed mathematically. The relationship between the cone semiangle, θ, and the x-coordinate of the cone vertex, −d, is derived for a given chisel edge angle and nominal relief angle at the outer corner. This relationship is used to study the effects of grinding cone parameters on drill point geometry. The analysis indicates the existence of an optimum θ value for best drill performance.
Three-Dimensional Analysis of Hypoid Gears
Authors: Daniel I. M.
Published: November 2010

A three-dimensional photoelastic analysis using the stress-freezing and slicing techniques was conducted to obtain stress and load distributions in a hypoid gear pair. Precise full-scale plastic models of a gear and pinion were manufactured. A special mounting fixture was designed and built of the same photoelastic plastic as that used for the model. A set-up gage was also designed and manufactured for gaging the gear and pinion settings. Fine adjustments were made by means of shims. The desired contact, calculated to produce maximum fillet stresses, was checked with a marking compound and gaged with a stock-dividing gage. A loading device was used to apply pure torque to the pinion. The assembled model was loaded and taken through the stress-freezing cycle. Subsequently, the teeth under engagement were sliced and analyzed to obtain contact and fillet stress distributions.
An Anaerobic Biochemical Laboratory
Authors: Kordyban E. S. , Canty J. M.
Published: November 2010

For the study of certain enzymes, Dr. E. R. Stadtman, Chief, Laboratory of Biochemistry at the National Institutes of Health, desired a room where he could conduct many of the standard chemical laboratory procedures in an environment essentially free of oxygen. This unusual requirement presented many challenging problems from the standpoint of ease of operation, personnel safety, and economy of operation. This paper describes the parameters which were evaluated to design this unique facility including the method of obtaining and maintaining an oxygen free atmosphere, the life support system for the personnel, and safety features for normal and for emergency operations. The experience gained in actual use of this facility has indicated that experiments in a laboratory of this type can be conducted efficiently and safely.
Failure Prediction Through the Theory of Stochastic Excursions of Extreme Vibration Amplitudes
Authors: Sankar T. S. , Xistris G. D.
Published: November 2010

This paper attempts to propose a prediction on the failure of machinery resulting from high vibration amplitudes. Since the monitored record is generally in the form of a randomly fluctuating signal, the principles of stochastic excursions are employed in the investigation. Considering the total record to be made up of piecewise stationary signals with normal distributions, an initial estimation on the state of the machine is obtained by determining the first passage probability of the random excursion about a specified safe level. Further information on the incipient failure of the machine is obtained by evaluating the probability of durations of the excursion above the critical level. A possible maintenance program for vibrating machinery is proposed on the basis of two probabilities, and discussed using a particular industrial application.
Stability of an Unsymmetrical Rotating Cantilever Shaft Carrying an Unsymmetrical Rotor
Authors: Arnold R. C. , Haft E. E.
Published: November 2010

Previously, investigations pertaining to the stability of a rotating unsymmetrical shaft carrying an unsymmetrical rotor have considered the mass of the shaft to be negligible when compared with the mass of the rotor. This paper considers a system formed by joining an unsymmetrical rotor to an unsymmetrical cantilever distributed-mass shaft. Numerical examples and experimental data are presented.
Polydyne Cam Mechanisms for Typehead Positioning
Authors: Kanzaki K. , Itao K.
Published: November 2010

This paper describes a cam design method for typehead positioning in high-speed teleprinters. By this method, residual vibrations are extinguished at plural adjacent rise times and reduced over a comparatively wide range of rise times. The polynomial equations for the cam followers are determined upon consideration of the boundary conditions and the characteristics of the residual vibrations. The theoretical results are verified by the experiments.
Free Vibrational Characteristics of Pretensioned Cable Roofs
Authors: Bathish G. N.
Published: November 2010

Cable roofs are analyzed using nonlinear membrane theory. The cable network is simulated by an equivalent thin elastic prestressed membrane without shear rigidity. The equations of motion for the vibrating membrane are formulated by considering the static equilibrium position of the membrane as the position of the membrane after it undergoes nonlinear deformation due to uniform transverse load over the projected area of the membrane. The equations of motion are then solved for natural frequencies and associated mode shapes by restricting the analysis to small amplitude vibrations about the static equilibrium position. Two special cases are considered: a flat rectangular membrane, and a membrane that has the shape of a hyperbolic paraboloid surface that is rectangular in plan. Comparisons between linear and nonlinear membrane theory solutions are presented.
An Automated Method for Evaluating Truck Design
Authors: Krauter A. I. , Bartel D. L.
Published: November 2010

A systematic method for the design and evaluation of tractor-semitrailer truck systems and components is presented. The method is general and involves the combination of simulation and optimization techniques to obtain an automated design procedure. An application of the method is given which uses the procedure to evaluate an ideal proportional braking system based on the stability and braking performance of the truck. A quantity which measures the lateral stability of the truck is used to show that ideal proportional braking can produce nearly optimal lateral behavior. The results obtained from the investigation also show that the combined design procedure is an effective method for studying and evaluating complex systems.
Natural Frequency Determination of Long Span Floor Slabs
Authors: Chadha J. , Allen D. L.
Published: November 2010

This paper presents a general procedure for calculating the natural frequencies of rectangular plate structures which have beam stiffeners in the interior and at the boundaries. The technique of analysis accounts for shear deflections and rotary inertia of the plate. The effect of torsional and flexural reactions of the supporting beams on the plate-beam structure has also been included. The natural frequencies are compared with experimental values and also with those obtained by orthotropic plate approximation and Rayleigh’s method.
Dynamic Force and Torque Analysis of Mechanisms Using Dual Vectors and 3 × 3 Screw Matrix
Authors: Bagci Cemil
Published: November 2010

The method of determining dynamic force and torque distributions in mechanisms by using dual vectors and 3 × 3 screw matrix is presented. The dual equilibrium equations for each moving link of a mechanism are written as a null resultant dual force vector in a reference system located on the link. The resulting 6 × (n – 1) equilibrium equations for an n-link mechanism are solved for the unknown force and torque components at the pair locations, and for the input force or torque required to drive the mechanism to produce the specified dual output force. The dynamics of the mechanism is governed by introducing the dual inertia force acting on a link, which is determined as the negative of the time rate of change in the dual momentum of the link due to its own mass and mass moments of inertia, in the dual equilibrium equation for that link. Dynamic analyses of the 4R plane and the RCCC space mechanisms are performed. Dynamic transmissivities are defined. The RCCC mechanism is analyzed in a numerical example and the results of the dynamic distributions are compared with those of static distributions.