bluuebunny/crossref_metadata_2025 huggingface dataset:
Rolling Bearing Life Modifying Factors for Film Thickness, Surface Roughness, and Friction
Authors: Tallian T. E.
Published: March 2013

This paper facilitates practical calculation of rolling contact fatigue life, allowing for material, lubrication, and surface topography effects. Modifying factors for the predicted fatigue life are given for: material matrix strength; material defect severity; EHD film thickness/surface roughness ratio Λ; surface asperity slope σθ and boundary lubricated traction coefficient μa. Readily evaluated formulas are provided for the above factors. Calculated results show predicted life versus Λ with σθ and μa as parameters. Comparison with experimental data shows that the model covers most documented test results of life versus Λ. Scanty experimental data covering σθ and traction effects on life are compatible with the model predictions.
Fluid-Film Journal Bearings Operating in a Hybrid Mode: Part I—Theoretical Analysis and Design
Authors: Koshal D. , Rowe W. B.
Published: March 2013

Oil-lubricated plain hybrid journal bearings have been investigated theoretically and experimentally to determine the hybrid (hydrostatic/hydrodynamic) performance. The paper consists of two parts: Part I deals with the theoretical treatment of results, and Part II describes the experimental investigation. It is demonstrated that when two rows of inlet lubricant sources are employed in a plain hybrid bearing, greater load-carrying capacity is obtained by positioning the entries near the ends of the bearing rather than at the center or at quarter stations. These results extend previous work by presenting data for a wide range of power ratio (K). The parameter K is defined as the ratio of friction power to pumping power. Increasing K has the same effect as increasing speed for a particular bearing system. A new basis for optimizing hybrid bearings is described. The bearings to be optimized are compared with a reference bearing, on a basis of load/total power; a technique which is not required in other bearings where load does not increase rapidly with power ratio. Plain hybrid bearings are compared with conventional recessed hydrostatic journal bearings and with axial groove hydrodynamic journal bearings. It is found that plain hybrid bearings are superior in performance to recessed journal bearings at low eccentricity ratio and low speed. Also plain hybrid bearings are comparable to axial groove hydrodynamic journal bearings at a high eccentricity ratio and high speed with advantages for variable directions of loading. Furhermore the hydrostatic effect tends to raise the whirl onset speed.
A Load Combination Method for Aseismic Design of Multiple Supported
Piping Systems
Authors: Suzuki K. , Sone A.
Published: March 2013

A new load combination scheme for seismic response calculation of piping systems subjected to multiple support excitations is presented. This scheme has an advantage, such that the cross-correlation among support excitations are properly taken into account by use of a stationary random vibration approach. The authors also present the idea of generating a “multi-excitation floor response spectrum.” First, using a simple analytical SDOF piping system to two support excitations and a simple Z-shaped piping model for shaking test, the combination law is supplied to various correlation cases of two support excitations and the maximum responses of piping in a fundamental mode is calculated. Second, nonlinear characteristics such as gap and friction appearing between piping itself and supports are specifically investigated. The response effect due to these nonlinearities is evaluated by the results through the shaking test with a piping-support structural model, and the amount of response reduction effect is represented by “a response reduction factor β.”
Design of Composite Cylindrical Vessels for Fluid
Loading
Authors: Banks W. M. , Tooth A. S. , Wilson P. M.
Published: March 2013

A theoretical approach is presented to examine the problem of the fluid loading of a simply supported Glass Reinforced Plastic (GRP) composite cylindrical pipe. The shell layup is composed of specially orthotropic layers, the arrangement of which may be nonsymmetrical through the wall thickness. The theory is developed using Sanders’ thin shell theory, neglecting the effect of transverse shear. An example of the use of the method is given, where the behavior of a horizontal pipe is examined when it is partially or totally filled with fluid. Three layups are examined, one of an isotropic construction using chopped strand mat (CSM) and two of a laminated construction.
Finite Element Analyses of a Butterfly Valve Assembly
Authors: Goksel B. , Rencis J. J. , Noori M.
Published: March 2013

Two and three-dimensional finite element analyses of a butterfly valve assembly subjected to static fluid pressure were carried out using commercial code ANSYS. Good agreement between the experimental and finite element results were obtained. Sensitivity of results to various boundary and loading conditions was also investigated.
A Fourier Series Back-Computation Method for the Parting-Out Step in
Residual Stress Measurements in Pipes
Authors: Shadley J. R. , Sorem J. R. , Rybicki E. F.
Published: March 2013

The first step in a widely used destructive procedure for measuring through-thickness residual stresses in pipes is a parting-out step in which a coupon is cut from the wall of the pipe. Strain gages provide information on the stress changes that take place at the two surfaces of the coupon when the coupon is removed. Back-computation methods are applied to the laboratory data to provide estimates of the residual stresses that were in the pipe before the coupon was parted-out. The laboratory data needed for the back-computation method are the residual stress distribution in the parted-out coupon, and the stress changes that occured at the surfaces of the coupon when it was parted-out. A simple back-computation method for the parting-out step assumes that the changes that occur in the through-thickness stress distribution of the coupon when it is parted out can be described by a straight line, the end points of the line being determined by the stress changes at the surfaces of the coupon. However, if the width of the coupon in the circumferential direction is small (which is often the case for coupons cut from pipes), this straight line back-computation method can lead to errors in the circumferential residual stress distribution estimate it provides. This paper presents an alternative back-computation procedure based on the Fourier series. Example problems presented in the paper show the Fourier series back-computation method to be accurate, even for narrow coupons, and to be quick and easy to apply.
Stable and Unstable Crack Growth of A508 Class 3 Plates Subjected to
Combined Force of Thermal Shock and Tension
Authors: Yagawa G. , Ando Y. , Ishihara K. , Iwadate T. , Tanaka Y.
Published: March 2013

An urgent problem for nuclear power plants is to assess the structural integrity of the reactor pressure vessel under pressurized thermal shock. In order to estimate crack behavior under combined force of thermal shock and tension simulating pressurized thermal shock, two series of experiments are demonstrated: one to study the effect of material deterioration due to neutron irradiation on the fracture behavior, and the other to study the effect of system compliance on fracture behavior. The test results are discussed with the three-dimensional elastic-plastic fracture parameters, J and Jˆ integrals.
Effect of Creep Crack Growth on Life of Elevated Temperature
Stainless Steel Components
Authors: Becht C. , Buchheim G. M.
Published: March 2013

The traditional approach to high temperature design of process equipment has been directed towards prevention of creep rupture in nominally defect free structures. However, experience has shown that many failures are by the growth of cracks that may have been introduced during fabrication, repairs, or operation. This growth is via a localized creep mechanism termed creep crack growth. Both load-controlled, primary stress and deformation-controlled (e.g. thermal), secondary stress can contribute to this crack growth. Simplified methods were used to predict creep crack growth due to primary and secondary stress. This required development of a solution for crack growth due to secondary stress that considered simultaneous crack growth and load relaxation. Closed-form solutions were developed based on the C* integral that yielded crack advance as a function of time and initial load. The predictions compared very well with the results of a deformation-controlled compact tension creep crack growth experiment. Parametric evaluations showed that only very shallow cracklike defects can be tolerated in highly stressed areas. Cracks can advance very quickly due to both high primary or high secondary stresses. With primary stresses at the ASME Boiler and Pressure Vessel Code Section VIII, Div. 1 limits, cracks as shallow as 1.3 mm (0.05 in.) can reduce average life to less than 100,000 hr. Where cyclic secondary stresses exceed shakedown limits, life may be limited to a relatively small number of start-up/shutdown cycles.
Sensitivity of the Dynamic Behavior of Structures to System Parameter
Changes
Authors: Nordmann R. , Eckey H. , Kaas P. , Steinwarz M.
Published: March 2013

A new calculation procedure has been developed to evaluate the influence of parameter changes to the dynamic behavior of structures. By this sensitivity analysis the variations of natural frequencies and natural modes can be expressed, generated by specific parameter alterations. Combined with modal methods, for example the response spectrum modal analysis, the changed dynamic response (displacements, internal forces) can also be found. The algorithm is suitable in connection with standard finite element routines, to investigate the effect of parameter modifications in relation to the dynamic characteristics of an original system. For a large vessel piping system, the influence of a spring stiffness variation to the natural frequencies and internal forces is demonstrated.
A Test and Analysis of the Multiple Support Piping
Systems
Authors: Chiba T. , Koyanagi R. , Ogawa N. , Minowa C.
Published: March 2013

One of the current topics in the seismic design of piping systems is the overall reliability of them in earthquake events. Actual piping systems are generally supported by independent structures such as vessels and steel structures. So, it is very important to clarify the behavior of actual piping systems during the seismic events. For this purpose, the analytical method of multiple excitation problems is a preferable approach to not only evaluate the actual behavior of the piping systems, but also improve the reliability of piping systems. To clarify the dynamic characteristics of the piping systems and to assess the computational methods in the linear system subjected to multiple support excitations, an experimental study using a realistic large-scale piping model has been conducted. The equations for the multiple excitation problem have been validated and the adequacy of the multiple response spectra method has been confirmed by the comparison of the test results with the analytical one. This paper reports the results focusing on the analytical methods of the multiple support piping system. It is noted that the multiple response spectrum method is efficient for the multiple excitation problems.
Large Deformation Analysis of an Elastic-Plastic Cantilevered
Beam
Authors: Nicholson D. W.
Published: March 2013

This study concerns the analysis of the deflection of an elastic-plastic cantilevered beam. Three regions of solution are treated: (i) purely elastic response at low loads; (ii) elastic-plastic response without a hinge, for intermediate loads; and (iii) elastic-plastic response with a hinge for loads corresponding to the fully plastic bending moment at the built-in end. Most existing solutions for this type of problem involve various approximations avoided here, for example, ignoring the elastic part of the strain or using upper bounds based on limit analysis. By avoiding such approximations, the solution given here may be useful as a benchmark for validating finite element codes in the large deformation elastic-plastic regime. Several aspects of the solution are analyzed: (i) the load-deflection relation; (ii) the growth of the elastic-plastic zone; (iii) limiting cases; (iv) the residual configuration; (v) the small bending configuration. A numerical procedure based on Runge-Kutta methods is used, leading to the load-deflection relation in graphical form.
Equivalent Damping in Piping Due to Local Yielding
Authors: Lazzeri L. , Scala M.
Published: March 2013

A method is presented to 1) account for ductility effects in the response of one degree of freedom systems by means of evaluating the frequency shift and additional damping; 2) evaluate the energy dissipation which takes place in piping due to local yielding in elbows.
Turbulence-Induced Vibration of Tube Bundle in Cross and Parallel Jet
Mixed Flow
Authors: Kawamura K. , Yasuo A.
Published: March 2013

In the multi-tube type of heat exchanger, baffle plates are located at appropriate intervals to support the heat transfer tubes. Depending on the baffle plate type employed, the flow field in the tube bundle will consist of a mixture of the cross flow (the fluid flows at right angles to the tube bundle along the baffle plate surfaces) and the parallel jet flow (the fluid streams through channels such as the flow holes of the baffle plates in the form of jets and flows in parallel with the tube bundle). Vibrations induced by the flow can cause fretting wear and fatigue of the heat transfer tubes. Therefore, it it essential to establish a method of evaluating heat transfer tube vibrations induced by the mixed flow for the purpose of evaluating the integrity of heat exchanger tubes. In this paper, three different flows, that is, cross, parallel jet and mixed flows, were simulated in order to clarify the relationships between the flow conditions and vibration of the tube bundle, and to study a method for evaluating tube bundle vibrations induced by turbulence in the mixed flow field by using the vibration characteristics in the cross flow field and the parallel jet flow field.
Dynamic Forcing Function for Flow-Acoustic-Induced
Vibration
Authors: Wang T.
Published: March 2013

Vibration problems in piping systems can manifest themselves in two forms: excessive noise generated from wall flexural vibrations, that in combination with jet noise itself may exceed OSHA limits, and piping system vibration, which could lead to fatigue failure at stress risers. Thus, a comprehensive dynamic forcing function for flow-acoustic-induced vibration on piping system needs to consider both the flexural and system excitation sources. Jet column instabilities and acoustic standing waves are utilized to identify the vibration sources in a large-capacity steam piping system. Initial noise generation originates from approximately six jet diameters downstream of a control valve. It consists of two sharply defined high-frequency sources, the shock cells and the large-scale axisymmetric coherent turbulent structure generated from the nonlinear shear layer instability. These sources effectively excite wall flexural vibrations because of their nonzero net dynamic forcing on pipe “shells.” The compact shock and instability wave noise sources further excite the low-frequency acoustic standing wave in the acoustic duct formed by the discharge piping. The low-frequency acoustic standing wave excites the piping system vibration axially. The piping system was also excited transversely by a more potent vibration source incurred by the spiral mode provoked by a piping elbow. Field observation and measurement of the vibration problem of a large-diameter piping system confirm the prediction.
Simulation of Tube-to-Support Dynamic Interaction in Heat Exchange
Equipment
Authors: Fisher N. J. , Olesen M. J. , Rogers R. J. , Ko P. L.
Published: March 2013

Tubes within tube and shell heat exchange components are supported at intermediate points by support plates. Flow-induced vibration of a tube can cause it to impact or rub against a support plate or against adjacent tubes and can result in tube fretting-wear. The tube-to-support dynamic interaction is used to relate experimental wear data from test rigs to real multi-span heat exchanger configurations. Analytical techniques are required to estimate this interaction in real heat exchangers. Simulation results from the VIBIC code are in good agreement with three examples from the open literature and are in reasonable agreement with measurements from the CRNL single-span room temperature fretting-wear rigs. Therefore, the VIBIC code is a good analytical tool for estimating tube-to-support dynamic interaction in real heat exchangers.
Measurement of Tube-to-Support Dynamic Forces in Fretting-Wear
Rigs
Authors: Fisher N. J. , Ingham B.
Published: March 2013

Tubes within tube and shell heat exchangers are supported at intermediate points by plates. Flow-induced vibration can cause tubes to impact and rub against these supports, or other tubes, and can result in tube fretting-wear. The tube-to-support dynamic interaction, which consists of dynamic contact forces and tube motion, is used to relate single-span wear data to real heat exchanger configurations consisting of multi-span tube bundles. This paper describes the technique used to measure tube-to-support dynamic forces in the Chalk River Nuclear Laboratories impact fretting-wear test facility and reports test results that validate the technique. The force measurement technique is shown to provide a reasonable measure of dynamic contact forces.
Vibration of Tube Bundles in Two-Phase Cross-Flow: Part
3—Turbulence-Induced Excitation
Authors: Taylor C. E. , Currie I. G. , Pettigrew M. J. , Kim B. S.
Published: March 2013

An extensive experimental program was carried out to study the vibration behavior of tube bundles subjected to two-phase cross-flow. Turbulence-induced excitation is discussed in Part 3 of this series of three papers. Random vibration response to turbulence-induced excitation is a significant vibration mechanism in heat exchanger tube bundles subjected to two-phase cross-flow. The vibration responses of centrally located tubes in four tube bundle configurations subjected to air-water cross-flow was measured. The results are presented in the form of a normalized forced-excitation spectrum which can be used as a design guideline over a void fraction range from 25 percent to 99 percent and over a practical range of flow rates. The data are further analyzed to determine the dependence of the vibration response on Reynolds number, void fraction and frequency. Measurements taken on a single tube, a row of tubes and on tubes having varying end conditions were used to assist in interpreting the bundle data.
Flow-Induced Vibration Analysis of an Integral Economizer
Once-Through Steam Generator
Authors: Au-Yang M. K. , Brenneman B.
Published: March 2013

The integral economizer once-through steam generator is a second-generation steam generator used in B&W's 205-fuel assembly nuclear power plants. Besides having an integral economizer, this steam generator differs from the first generation units, sixteen of which have been operating with B&W's 177 fuel assembly nuclear power plants for more than ten years, in having a much higher flow rate. This higher flow rate induces a correspondingly higher fluid-dynamic load on all of the steam generator internal components, particularly the tube bundle. This paper describes the flow-induced vibration design analysis of this second-generation nuclear steam generator. The three most commonly known flow-induced vibration phenomena were considered: fluid-elastic instability, turbulence-induced vibration and vortex-induced vibration. To minimize uncertainties in the many experimentally determined input parameters such as damping ratios, Connors’ constant and the dynamic pressure power spectral densities, a parallel analysis was carried out on the operating first-generation steam generator, and the results compared. The analytical results were verified by the recent start-up of B&W's first 205-fuel assembly nuclear plant. No vibration problems were encountered during either the pre-operational test or in several months of full power operations.
Pressure Suppression Containment Design—Current State of the Art
Authors: Miller D. R.
Published: March 2013

A summary of the thermodynamic design limits for pressure suppression containments for nuclear reactors is presented. Those parameters which must adhere to tested values are tabulated and discussed. An analytical model is described and is shown to accurately predict the existing test data. A graphical technique for predicting the transient peak containment pressure, based on the model, is presented for use in containment design.
Effect of Water Chemistry and Design on Corrosion of Carbon Steel Tubed Feedwater Heaters
Authors: Morris E. B. , Phillips Henry
Published: March 2013

This investigation deals with the factors responsible in controlling the corrosion of carbon steel tubed feedwater heaters. Water chemistry variables include pH, hydrazine and carbon dioxide. Heater design considerations include the effect of velocity and inlet channel distribution. Although there are certain unexplainable findings with respect to corrosion behavior, the installation tested proves the acceptability of carbon steel for feedwater heater service.
Some Factors Controlling Hydrogen Damage in Carbon Steel
Authors: Knoedler E. L. , Dalgaard S. B.
Published: March 2013

Hydrogen damage in carbon steel is assumed to be caused by corrosion hydrogen. Theoretical considerations indicate the equilibrium partial pressure of hydrogen at the carbon-steel surface, exposed in pure water at high temperature, is significantly high. Acidification of the water further increases the partial pressure of hydrogen by large values. Under normal pure conditions a major part of the corrosion hydrogen may readily be released to the coolant. Contamination of the reacting magnetite surface with strong catalytic poisons could, however, block the escape of hydrogen with the coolant. In this event hydrogen could be forced into the steel at high pressure. Free-energy considerations indicate the resultant decarburization of the steel and the partial pressure of methane formed could readily jeopardize the integrity of the material.
A Research Study on Internal Corrosion of High-Pressure Boilers—Final Report
Authors: Goldstein P. , Burton C. L.
Published: March 2013

The following report is the last in a series of four describing the progress and results of “A Research Study on Internal Corrosion of High Pressure Boilers.” The first three reports described the background, scope, and organization of the program, as well as the test facility and the results of Phases I, II, and III. This final report includes results of the eight Phase IV tests and a discussion of the results and conclusions from the entire program. Phase IV test results include data and observations on plug-type corrosion and hydrogen damage. The discussion of results describes the mechanisms involved in these types of attack, as well as the causes of caustic gouging. Observations on chemical hideout and deposition are discussed in addition to the heat transfer and fluid flow phenomena involved in nucleate boiling and departure from nucleate boiling.
Massive Recirculation as a Method of Minimizing Corrosion in the Combustion of Residual Fuels
Authors: Reba Imants
Published: March 2013

Metal surfaces exposed to combustion gases from residual fuels suffer from fouling and severe corrosion. Several methods currently in use to combat these effects include chemical treatment of the fuel, combustion at near stoichiometric conditions, and the use of protective coatings. This study introduces another method based primarily on improved burner technology, specifically, combustion with massive, external recirculation. Short (10-hr) and long (30-hr) exposure time tests have demonstrated that the combustion of untreated oil having a high vanadium and sodium content with sufficiently large recirculation produces corrosion of essentially the same magnitude as that experienced from the combustion of diesel fuel without recirculation. These beneficial effects of recirculation are greatest at conditions giving rise to highest corrosion rates, i.e., at high excess air and high metal temperature.
Radioactive Sulfur Oxide Studies of External Corrosion Reactions on Surfaces
Authors: Krause H. H. , Levy A. , Reid William T.
Published: March 2013

Radioactive sulfur-35 has been used as a tracer to determine the roles of SO2 and SO3 in reactions leading to formation of alkali iron trisulfates. The reactivity of 30 ppm SO3 with surfaces containing iron oxides, alone or mixed with alkali sulfates, has been found to be much greater than that of large amounts of SO2 + O2 over the temperature range 900 to 1300 deg F. The SO3 reactivity was found to be a maximum at 1200 deg F, while the SO2 reactivity was at a minimum about 1150 deg F. Complex sulfates were formed most readily with K2SO4-Fe2O3 surfaces, followed by Na2SO4-steel, and Na2SO4-Fe3O3 surfaces.
Air Pollution Characteristics of Gas Turbine Engines
Authors: Sawyer R. F. , Teixeira D. P. , Starkman E. S.
Published: March 2013

The current contribution of gas turbine engines to air pollution is small. Improved control of emissions from other sources, increased use of gas turbines, and changes in gas turbine emission characteristics may cause the air pollution contribution of gas turbines to become more significant. A laboratory model gas turbine combustor was used for investigation of the internal burned gas composition. Of particular concern was nitric oxide. It was found that nitric oxide concentration is controlled by the kinetics of its formation. Evidence of the chemical kinetic behavior of carbon monoxide and unburned hydrocarbons also was obtained.
Current Status of Titanium-Boron Composites for Gas Turbines
Authors: Metcalfe A. G. , Schmitz G. K.
Published: March 2013

A process to manufacture titanium-boron composites has been demonstrated with a 30-filament tape in which reaction is controlled to a few hundred Angstroms of boride. This tape has good properties—indicating efficient use of the boron reinforcement—combined with good reproducibility (coefficient of variation of tensile properties approaches 2 percent). Simulated exposures confirm predictions that many thousands of hours of service life are possible at temperatures up to 1200 F. In addition, creep, fatigue, compression, cross tensile, and shear properties are presented. Application of this metal matrix tape to gas turbines is discussed. It is shown that the advantages of boron-reinforced plastic tapes in manufacturing are combined with the advantages of a metal matrix for shear load transfer, cross tensile strength, erosion resistance, and high-temperature performance.
Low Cost Capacity For Peaking Generation
Authors: Miliaras E. S.
Published: March 2013

A means of obtaining peaking generation from existing generating units is proposed, by installing lower steam temperature boiler capacity in parallel with the existing boiler; the additional steam bypassing the high pressure turbine and the reheater into the intermediate pressure turbine. The economics compare very favorably to the available methods of obtaining peaking generation. Future peaking capability built into baseload units is also considered.
A High Strength Nickel-Base Alloy With Improved Oxidation Resistance up to 2200 deg F
Authors: Waters W. J. , Freche J. C.
Published: March 2013

A high strength nickel-base alloy has been developed which compares favorably in oxidation resistance with known high strength nickel-base alloys. The alloy, although basically a cast material, also possesses workability potential. After 310 hr exposure to air at 1900 deg F, the alloy had a weight gain of 1.8 mg/cm2. The total affected zone, oxidized material plus depletion zone, was 0.4 mil. This compares with a weight gain of 3.0 mg/cm2 and a total affected zone depth of 3.3 mils for Rene´ 41 after 100 hr exposure at 1900 deg F. In sheet form after 8 hr at 2200 deg F, its oxidation resistance was approximately the same as that of Rene´ 41 at 1900 deg F. Tensile strengths of the alloy after rolling and heat-treatment ranged from an average of 185,000 psi at 1400 deg F to 3000 psi at 2200 deg F. Maximum elongation was 55 percent and occurred at the latter temperature. At 1900 deg F, average tensile strength was 64,500 psi in the as-cast condition, and 54,000 psi after rolling and heat-treatment. Stress rupture data for low and intermediate stress levels were obtained. In the as-cast condition, use temperatures for 500, 100, and 10-hr life at 15,000 psi are 1815, 1895, and 2010 deg F, respectively. At 8000 psi and 2125 deg F, rupture life was 13 hr and compared favorably with some of the strongest known nickel and cobalt-base alloys. The very good high temperature oxidation resistance, good high temperature strength, and at least limited workability of this alloy suggest that it may be applicable for use in advanced gas turbine engine components.
Sulfur Oxide Reactions: Radioactive Sulfur and Microprobe Studies of Corrosion and Deposits
Authors: Krause H. H. , Levy A. , Reid William T.
Published: March 2013

The reactions of SO2 and SO3 with catalytic surfaces containing iron oxides, alone and in combination with various sodium salts, have been investigated. The SO3 concentration gradients above the surfaces were measured using a microprobe technique, showing that, as much as 2000 ppm SO3 can exist in a slowly flowing gas stream immediately next to a surface. Radioactive sulfur was employed as a tracer to determine the roles of SO2 and SO3 in reactions with these surfaces leading to formation of alkali iron trisulfates. These measurements indicated that on a molar basis, SO3 is 30,000 times more reactive than SO2 + O2 in forming complex sulfates with a mixture of sodium sulfate and iron oxide.
Radiation and Convection Heat Transfer in a Porous Bed
Authors: Beckman W. A.
Published: March 2013

The one-dimensional steady-state temperature distribution within an isotropic porous bed subjected to a collimated and/or diffuse radiation heat flux and a transparent flowing fluid has been determined by numerical methods. The porous bed was assumed to be nonscattering and to have a constant absorption coefficient. Part of the radiation absorbed by the porous bed is reradiated and the remainder is transferred to the fluid by convection. Due to the assumed finite volumetric heat transfer coefficient, the bed and fluid have different temperatures. A bed with an optical depth of six and with a normal incident collimated radiation heat flux was investigated in detail. The radiation incident on the bed at the fluid exit was assumed to originate from a black surface at the fluid exit temperature. The investigation covered the range of incident diffuse and collimated radiation heat fluxes expected in a nonconcentrating solar energy collector. The results are presented in terms of a bed collection efficiency from which the fluid temperature rise can be calculated.
Performance Evaluation of Pumps in Air and Water
Authors: Wood Glenn M.
Published: March 2013

To explore the feasibility of establishing pump performance in air, two different designs were tested over the same range of shaft speed and flow rate in both water and air. The larger unit of 3000-gpm capacity was of unshrouded design, whereas the smaller, 195-gpm capacity pump was fabricated with a full tip shroud on the impeller. Although similar trends in performance were observed for each pump tested in air and water, some dissimilarities were observed. In particular, the head rise characteristic curves for both pumps were noticeably higher in air than in water. This is contrary to trends predicted by Reynolds number effects and is apparently due to significant difference in the impeller tip leakage flows when pumping liquid or gas.
A Laboratory Study of High-Temperature Corrosion on Fireside Surfaces of Coal-Fired Steam Generators
Authors: Goldberg S. A. , Gallagher J. J. , Orning A. A.
Published: March 2013

Three experimental approaches gave significant information on high-temperature fireside corrosion: 1 Sodium and potassium chlorides, injected through a gas flame, were deposited as such and then converted to sulfates on an iron surface. 2 Samples of mixed alkali and iron sulfates first showed decomposition and then formed melts at temperatures as low as 1070 deg F. This temperature is within the range that might be expected for fireside surface temperatures on superheater and reheater tubes of large steam generators. 3 Alkali metal chlorides and sulfates, in partial coverage of metal disks and in a flue gas atmosphere, formed fused deposits at temperatures as low as 900 deg F. Complex alkali iron sulfates may cause corrosion either by direct electrolytic corrosion or by altering the normally protective iron oxide scale so that the metal is exposed to direct oxidative corrosion.
Proposed ASME Performance Test Code for Nuclear Reactor Fuel
Authors: Moore W. T.
Published: March 2013

In the process of drafting a Performance Test Code for Nuclear Reactor Fuel, a question has arisen as to whether the present state of knowledge and experience will permit the writing of a useful code at this time. This paper summarizes the information currently available, states what can be accomplished by the type of code which can be written now, and recommends that the code be written, incorporating information currently available for immediate use and providing a framework for the addition of further information as it becomes available.
Testing Pumps in Air
Authors: King J. A.
Published: March 2013

Research on pumps, particularly those for transporting cryogenic fluids, is very expensive. Rocketdyne has tested pumps with air as the working fluid and has found that a very good correlation exists between air test data and liquid test data. This paper gives a description of the air rigs used by Rocketdyne and compares the data taken in air with data taken in water, LOX, RP-1, and liquid hydrogen. Also presented is the effect of tip clearance on the head of an axial-flow pump as determined from air tests.
The Application of Controlled-Vortex Aerodynamics to Advanced Axial Flow Turbines
Authors: Dorman T. E. , Welna H. , Lindlauf R. W.
Published: March 2013

This paper describes a technique for improving turbine aerodynamic performance which has been made practical by advanced computer technology. This technique entails precise control of the blade row spanwise vortex distribution in other than a free-vortex plan in order to prevent excessive corner losses. Background data leading to the investigation of this technique are reviewed. The controlled-vortex technique was verified by a series of tests in a single-stage cold flow test rig. The results of these tests show that the controlled-vortex technique could be successfully applied to substantially improve turbine performance.
A Fluidic Technique for Measuring the Average Temperature in a Gas Turbine Exhaust Duct
Authors: Ringwall C. G. , Kelley L. R.
Published: March 2013

Circuit concepts and test data for a fluidic system to sense the average temperature in a gas turbine exhaust duct are presented. Phase discrimination techniques are used to sense the average wave velocity in a long tube and to produce an output pressure differential proportional to temperature error.
Oblique Flow Headers for Heat Exchangers
Authors: London A. L. , Klopfer G. , Wolf S.
Published: March 2013

The problem of the design of oblique flow headers for heat exchangers flowing low density fluids is considered. It is demonstrated by test that the theory already available in the literature provides an adequate basis for design for the single-pass “parallel flow” and “counterflow” configurations. The theory is summarized in the form of design equations and illustrated by specific application to the air-side flow in a gas turbine regenerator.
Carbon Dioxide Condensation Cycles For Power Production
Authors: Angelino G.
Published: March 2013

The thermodynamic performance of several condensation cycles employing carbon dioxide as working medium is analyzed and discussed. A balanced distribution of thermodynamic losses between mechanical components and heat exchangers attained through a compression performed partially in the liquid and partially in the gas phase yields cycle efficiencies which are among the highest achievable in present-day energy systems. At turbine inlet temperatures higher than 650 deg C single heating CO2 cycles exhibit a better efficiency than reheat steam cycles. This may prove of particular interest in connection with high temperature nuclear heat sources. However, the requirement of low temperature cooling water for a good cycle arrangement represents a geographical limitation to the widespread application of CO2 condensation cycles.
Developing a High-Powered Diesel Engine for Railway Traction
Authors: Schur T.
Published: March 2013

The paper deals, first of all, with the design criteria for the new Sulzer four-stroke locomotive engine being developed by the author’s firm and how some of these derived from two experimental engines which, although identical in construction, were operated on the four-stroke and two-stroke cycle, respectively. Field research as well as elaborate bench test facilities have been provided to perfect the new locomotive diesel engine. The work that has recently been carried out on some of the more important components of this is described. Some mention is made of the problems encountered with combustion and pressure charging at the high specific loads to which this engine type is being taken.
Metallurgical Considerations Involved in the Development of Nickel-Base High-Temperature Sheet Alloys
Authors: Richards E. G.
Published: March 2013

The effects of compositional variations and the influence of production methods and heat-treatment on the properties of titanium and aluminum-hardened nickel-base alloys are described to illustrate metallurgical considerations involved in development of nickel-base high-temperature sheet alloys. Particular attention is drawn to conflicting effects of compositional variations on the property requirements which must be specified for sheet material and to the need for compromise in order to obtain a satisfactory combination of properties.
The Split Compressor Differential Gas Turbine Engine for Vehicle Propulsion
Authors: Doyle G. N. , Wilkinson T. S.
Published: March 2013

The performance of the vehicular split compressor differential gas turbine (SCDGT) engine is compared to that of the variable geometry free power turbine (FPT) engine. Fuel consumption, engine braking, acceleration, and starting are considered, and it is concluded that the SCDGT has several important advantages. The SCDGT engine needs no speed-changing gearbox for forward drive, its part-load fuel consumption is at least as good as that of the FPT engine, and its acceleration and ease of starting are better.
Increasing Strength of Gas Turbine Alloys by Cold Work Prior to Aging
Authors: Richmond F. M.
Published: March 2013

The combined effect of cold work and precipitation hardening treatments on the room-temperature hardness and tensile properties of A-286, Waspaloy, and Unitemp® 212 has been investigated. Significant increases in these properties were found for all alloys. A brief study of the effect of the stress rupture properties of cold-worked and aged A-286 indicated no detrimental effects for the temperature and stress levels investigated.
The Effect of Vacuum Arc Remelting of Airmelt Electrodes on the Structure and Elevated Temperature Properties of a Nickel-Base Gas Turbine Superalloy
Authors: Richmond F. M.
Published: March 2013

Vacuum arc remelting of electrodes prepared by the vacuum induction melting process is currently being used to provide high integrity forging billet stock of complex nickel-base superalloys. The purpose of this investigation was to study the effect of vacuum arc remelting of airmelt electrodes on the structure and properties of a popular nickel-base gas turbine superalloy—M-252. A secondary purpose was to study the effect of solution temperature on carbide banding, grain size, and properties of the resulting material. The results indicate that the use of airmelt electrodes is feasible for this particular alloy and probably for other gas turbine superalloys of a similar chemistry. The effects of forging temperature on carbide solution and grain growth are similar to those previously noted in vacuum induction melted product. A differential grain size effect, apparently related to the straightening operation used to produce the bar stock, was found to have a significant effect on the rupture and elevated temperature tensile properties.
Prewhirl an Added Degree of Freedom to the Designer of Small Single-Shaft Gas Turbines
Authors: Shouman A. R.
Published: March 2013

The possibility of the advantageous use of adjustable guidevanes in the compressor inlet for the control of single-shaft gas turbines is discussed. Considering certain design specifications that are impossible to be met by a fixed-geometry, single-shaft machine, it is pointed out how the design specifications can be met utilizing an inlet guidevane system. This is merely used as an example to point out the possible merits of such a system and that it may allow the designer to meet some extraordinary design requirements.
Internally Generated Noise From Gas Turbine Engines. Measurement and Prediction
Authors: Smith M. J. T. , House M. E.
Published: March 2013

The noise sources from gas turbine engines are defined and their radiation patterns identified from test results. Examination of single-stage and full-scale engine compressor noise measurements leads to a prediction technique being evolved for inlet and efflux levels.
Interactions in Sulphur Oxide-Iron Oxide Systems
Authors: Levy A. , Merryman E. L.
Published: March 2013

Fe2O3-, Fe3O4-, NaOH-Fe2O3-, and NaOH-Fe3O4-coated substrates of Vycor and of iron were exposed to controlled gas mixtures containing SO2 and SO3. Sulfate and sulfide formation are examined and explained on thermodynamic grounds. Examination of the role of MgO coatings indicates a limited “protective” effect through its removal of SO3 from the gas stream.
Torsional Response of Systems
Authors: Pollard E. I.
Published: March 2013

Torsional resonance in coupled rotating systems such as multiunit turbine-gear-compressor trains is sometimes a serious problem and several shaft failures have been reported. Often it is desirable to know the magnitude of vibration in or near resonance. A procedure is developed whereby an alternating exciting torque of known magnitude and frequency is applied at any required point in the system and a digital computer solution is obtained for the resulting steady-state, torque in each shaft and deflection of each inertia. Use of this in the analysis of test data is illustrated. Methods are also developed whereby the foregoing steady-state solution is used to obtain approximate transient torques appearing in shafts when an a-c machine is short-circuited, and during acceleration through resonance. Correlation of computations with acceleration test data is shown.
Analysis of a Circular Cylindrical Shell Perforated by a Large Number of Radial Holes
Authors: Mahoney J. B. , Salerno V. L.
Published: March 2013

The present paper considers a circular cylindrical shell perforated by many radially aligned circular holes that pierce its surface in repeating rectangular patterns (Fig. 1). Eight “effective” stiffness coefficients are developed for this configuration by comparing the elastic strain energy density for an idealized perforated cylindrical shell element (shown in Fig. 2) to the energy density of an orthotropic cylindrical shell element. General equations for the perforated shell element are obtained by utilizing these eight “effective” stiffness coefficients. The general set of equations is then reduced to the usual three partial differential equations in terms of the u, v, and w-displacements. This set of displacement equations is solved for two specific cases; the first case is the rotationally symmetric one where the shell is considered completely perforated; the second case is that of a partially perforated shell. Here a portion of a perforated shell is joined with a portion of an isotropic cylindrical shell along two edges, where θ is constant (see Fig. 4).
Fatigue Properties of Nonferrous Alloys for Heat Exchangers, Pumps, and Piping
Authors: Gross M. R. , Schwab R. C.
Published: March 2013

The fatigue behavior of 13 nonferrous alloys used for corrosion-resistant heat exchangers, pumps, and piping systems was investigated over a broad life spectrum of 100 to 100 million cycles. Both cast and wrought copper-base and nickel-base alloys were studied. It is concluded that wrought Monel and forged Ni-Al bronze have the highest fatigue strengths, whereas gun metal and valve bronze have the lowest. The effect of salt water on fatigue performance was not found to be highly significant. The use of Langer’s equation to predict stress-cycle relationships gave satisfactory results for wrought alloys but appeared to be overly conservative for cast alloys.
The Effect of Nozzle Spacing on the Pressure Stresses at the Intersection of Cylindrical Nozzles and Shells
Authors: Stone R. M. , Hochschild S.
Published: March 2013

This paper considers the effect of nozzle spacing on the pressure stresses at cylindrical pressure vessel shell and nozzle junctures. This consideration is based on a photoelastic test conducted to determine if the stress indices of Section III of the ASME Boiler and Pressure Vessel Code may be used in analysis of reactor vessel designs containing circumferential nozzle spacings smaller than presently allowed by the Code. The five circumferential spacings used in the test were 109 deg, 34 deg, 30.2 deg, 26.4 deg, and 22.5 deg. The stresses at the locations of interest are presented as a function of nozzle spacing. These results show that the maximum stresses for spacings below the Code minimum are smaller than those at the Code minimum.
Elevated Temperature Autofrettage
Authors: Berman I. , Pai D. H.
Published: March 2013

Two new processes of cylinder autofrettage (prestress) have been analyzed and compared to the standard high pressure autofrettage. By means of a highly improved stress intensity distribution at design pressure, it was shown that a significant increase in allowable pressure and a reduction of autofrettage pressure may be achieved by the new processes.
Internal Corrosion of High-Pressure Boilers
Authors: Goldstein P. , Dick I. B. , Rice J. K.
Published: March 2013

This report is the second in a series of three describing the progress of “A Research Study on Internal Corrosion of High Pressure Boilers.” The first progress report, presented by H. A. Klein and J. K. Rice at the 1965 Annual Meeting of the ASME, describes the background, scope, and organization of the program as well as the test facility. This second progress report describes the results of the first half of the study. Results of tests with volatile, coordinated phosphate, and caustic boiler water treatment under conditions simulating a boiler with clean internal surfaces and one whose surfaces have been fouled with typical preboiler corrosion products, are included. Data relating to deposition and corrosion in the aforementioned environments are presented. The corrosion failure of a test tube due to “caustic gouging” and the discovery of an unusual effect of deposits on boiling characteristics are described.