Engineering Commons^™

Efficiency And Loss Mechanism Of The Electro-Fluid Dynamic Momentum Transfer Process Applied To Propulsion Systems Using Atmospheric Air As The Working Fluid, Roger Coy Crites

Masters Theses

"The general equations governing EFD (electrofluid dynamic) flow are established, simplified, and solved in closed form to provide a mathematical model of an ideal EFD propulsion system. This mathematical model, in conjunction with an analysis of ion-neutral and neutral-neutral molecular collision phenomena, indicates that the cause of inefficiency in the EFD propulsion system is the system entropy increase associated with the diffusion of ion momentum through the neutral fluid. This loss mechanism is shown to be analogous to resistive heating losses in a constant voltage linear electrical network and can be minimized by obtaining minimum ion mobility. It is shown …

Mutually Dependent Heat And Mass Transfer In Laminar Tube Flow, Gary Alfred Scheffel

Masters Theses

"An investigation is performed of the mutually dependent heat and mass transfer in laminar and hydrodynamically fully developed gas flow in a tube. Sublimation of mass occurs at the tube wall so that heat and mass transfer take place between the wall and the flowing gas stream. The wall of the tube is thermally insulated from the external environment with the result that the heat of sublimation is supplied by convective transport from the gas. The solution of this problem requires the simultaneous consideration of the energy and diffusion equations, with coupling provided by the boundary conditions. Mathematical expressions are …

Heat Transfer Through A Spherical Gas Shell, Adel Nassif Saad

Masters Theses

"The radiative transfer through an absorbing-emitting gas shell contained within black concentric spheres at uniform but different temperatures was investigated. A close form exact solution and an approximate solution were derived for the case of isothermal gas layer. The two solutions appear to compare well specially at low diameter ratios, and both agree with the radiative equilibrium solution in the thin limit. An approximate method was developed for the radiative equilibrium, non-isothermal gas layer, of the above problem. The method is based on the assumption of a hyperbolic emissive power distribution through the gas shell. The jump boundary conditions were …

Numerical Solutions Of The Torsional Oscillations Of A Shaft-Flywheel System, Mahendrakumar Ramkrishna Patel

Masters Theses

"The application of the finite-difference technique, the Fourier transform, and the Laplace transform for the solution of a system governed by the one-dimensional wave equation is examined. A specific example consisting of a continuous shaft-flywheel system acted upon by an exciting torque applied at a specific section of the shaft is studied. The exact solution to this example is obtained using the classical method of superposition of modes, and is used as a reference to evaluate the accuracy (in terms of the rms error) and relative efficiency (based on computer time) of three approximate solution methods. A sinusoidal excitation was …

Bound-Free Continuum Radiation From Non-Gray Nonisothermal Shock Layers, Chu Yih Wang

Masters Theses

"This study investigates the continuum radiative flux from nonisothermal stagnation shock layers composed of atomic gases. The general equations for the composition are derived and the Rankine-Hugoniot equations are simplified and solved to give the thermodynamic conditions of the shock layers. To accurately model the stagnation shock layer, the plasma must be considered to be nonisothermal. In the current study, linear shock layer temperature profiles are assumed. Consequently, the fluid dynamics and the radiation are uncoupled. The radiation model assumes one-dimensional radiative energy transport and considers only continuum processes. The radiative flux is calculated by considereing ground to free state …

The Influence Of A Carbon Ablation Layer On Radiation From A Hydrogen Shock Layer, Birbal Singh

Masters Theses

"The effect of ablation heat shields on the radiative heat transfer to vehicles entering hydrogen atmospheres at thermo-dynamic conditions similar to those expected in Jovian atmospheres is investigated. The shock layer is assumed to consist of two plane parallel layers, one consisting of pure hydrogen species, and the other consisting of carbon species only. Each layer is assumed to be in local thermodynamic equilibrium at its respective temperature. The thermodynamic conditions in the hydrogen layer are arrived at by solving the Rankine-Hugoniot Equations across the shock. The temperature of carbon layer is taken as (3000, 5000, and 7000ºK) to cover …

Analysis And Control Of Noise Produced By Small Pneumatic Tools, Phillip Ray Elam

Masters Theses

"Noise measurements were made near the exhaust of three small pneumatic tools operating under various loads and with various components removed. One-third octave analyses were performed on the noise for identification of noise sources and to determine possible noise reduction techniques. It was determined that the noise spectra consisted of broad band turbulent flow noise plus periodic components at the tool motor blade passage frequency and harmonics of this frequency. One tool, the nut setter, was selected for reverberant field noise analyses and noise reduction studies. Reverberant field measurements indicated that most of the tool noise was transmitted through the …

An Investigation Of The Adjustable Element Concept For Design Of Automotive Exhaust Mufflers, Phillip Scott Gegesky

Masters Theses

"The concept of the adjustable muffler is felt to be a step in the direction of easing the present tedium of constructing and testing prototype mufflers. The evaluation of such a muffler also furthers the knowledge of the interaction of acoustic elements. A review of past and present efforts in the design and evaluation of acoustic filters and filter elements is herein presented. Some consideration is given to phenomena, such as tube attenuation and transverse modes of vibration, which are encountered in muffler evaluation techniques. The characteristics of wave guides are discussed at length. The solution of the plane wave …

Magnetohydrodynamic Channel Flow With Non-Uniform Inlet Velocity Profiles, Gwok-Liang Chen

Masters Theses

"An analysis is made of laminar magnetohydrodynamic (MHD) flow development in the entrance region of a parallel-plate channel. The problem is formulated in general for any velocity distribution at the channel inlet by extending the linearization method of Sparrow, Lin, and Lundgren for non-MHD duct flows. This method involves linearization of the inertia terms in the equation of motion by introducing a stretched axial coordinate. A closed form solution is obtained for the velocity distributions which are continuous across the channel and along the length all the way from the entrance to the fully developed region. An expression for the …

Linear Analysis Of Pneumatic Dashpot Damping, Nathalal Gordhanbhai Patel

Masters Theses

"The linear analysis of pneumatic damping with orifice or capillary restrictions and with or without mean flow is presented. Temperature and pressure relationships are derived from energy considerations rather than the usual simplification of an assumed polytropic coefficient. Analytical results are compared with the experimental results and a coefficient of heat transfer, C_h, is defined for calculation of the equivalent linear damping factor C_d"--Abstract, page ii.

Design And Construction Of A Velocity Control System For A Low Turbulence, Vertical Wind Tunnel, Lawrence Vehslage Field

Masters Theses

"A low velocity (0 - 11m/sec), low turbulence vertical atmospheric wind tunnel has been designed and built by Inca Engineering Company of San Gabriel, California. This tunnel was assembled in the Cloud Physics Research Center at UMR. The tunnel is designed to aid in the study of phenomena associated with water drops suspended in a vertical air stream. This thesis describes the design and construction of the velocity control system for this tunnel. Constant speed, centrifugal fans are used to draw air through the tunnel. To allow these fans to operate at a constant efficiency, a valve system is used …

Thermal Stresses In Circular Plates Including The Effect Of Transverse Shear Deformation, An-Ton Liu

Masters Theses

"This thesis is an extension of the work of T. F. Lehnhoff which used the method suggested by Goodier to develop the Reissner-Goodier small displacement theory for plates subjected to lateral loading. The purpose of this work is to develop a more complete Reissner-Goodier small displacement theory for plates under general loadings, both lateral and thermal, and to provide a solution to the six governing coupled partial differential equations by using a process similar to that of Lehnhoff. Any loading, lateral and/or thermal, that satisfies the Dirichlet conditions of Fourier analysis and virtually any boundary conditions may be handled. Most …

Magnetohydrodynamic Stability Of Laminar Flow In The Entrance Region Of A Parallel-Plate Channel, Thomas Eldon Eaton

Masters Theses

"The hydrodynamic stability of laminar flow of an electrically conducting fluid flowing in a parallel-plate channel with an applied transverse magnetic field is investigated. The linear perturbation theory of hydrodynamic stability along with the assumption of low magnetic Reynolds number is applied to the governing equations to derive the governing rnagnetohydrodynarnic stability equation. A finite difference scheme is employed to numerically solve the magnetohydrodynamic stability equation. Neutral stability characteristics of the flow in the entrance region are obtained and presented. The neutral stability characteristics of the fully developed Hartmann flow are also re-examined and compared with those of a previous …

Interface Thermal Conductance With Metal Screens As Interstitial Material, William Edward Stewart Jr.

Masters Theses

"This thesis reports the results of an experimental investigation to determine the thermal conductance at the interface of metal specimens separated by wire mesh. Sets of metal specimens of copper, 2024-T4 aluminum, and 304 stainless steel were used. The specimens were cylindrical, axially aligned, and hydraulically loaded. All tests were conducted in an air environment. Pressure applied to the specimens ranged from 50 to 500 psig. Surface roughness of the interfaces varied from 5 to 20 micro inches. The wire mesh separators were of 304 stainless steel in 20, 30, 40, and 50 mesh. Results of the experiments show that: …

Influence Of Some Interstitial Materials On The Thermal Contact Conductance, Jin-Tyan Lin

Masters Theses

"Experiments have been conducted to investigate the effect of the interstitial materials at the interface of metals in contact. The test specimens were cylinders, axially aligned and loaded. Specimen materials were 606l-T6 aluminum alloy, and the contact fillers were stainless steel wire screens, aluminum foil, paper, and dielectric greases. The tests were conducted at atmospheric environment. The contact pressure ranged from 25 psi to 600 psi. The mean interface temperature ranged from 100 ºF to 200 ºF. Surface roughnesses of specimens were from 25 to 35 micro-inches, rms. The results of the investigation reveal that if the contact surfaces are …

Dynamic Analysis Of A Torsional Vibration Actuator, Narayandas Trikamdas Ashar

Masters Theses

"The objective of this study is the evaluation of a mechanical system, which includes a Hooke's joint, as a possible torsional vibration actuator. The essential requirement of such a system is to produce a periodically varying angular motion superimposed upon a mean constant speed rotation. The basic kinematics of a Hooke's joint suggest that it could be used to generate the type of motion desired. The mechanical arrangement of a system incorporating a Hooke's joint is described and the governing differential equations are developed. These equations are simultaneous, differential equations of second order and are highly nonlinear. Values of typical …

Transient Response Of A Vibration Isolation System, Hemendra Shantilal Acharya

Masters Theses

"A practical procedure for investigating the performance of a vibration isolation system under transient conditions is presented. For this investigation, an induction motor with an unbalanced rotor is studied during the period when it accelerates to its operating speed from rest. Using Newton's second law of motion, equations of motion are derived, first neglecting and then considering the effect of "inertia torque". This torque is produced by the inertia force resulting from vertical acceleration of the unbalanced mass. The equations are solved on a digital computer using the Runge-Kutta method of order 4. The results obtained are compared with those …

Vibration Of A Rotating Cantilever Beam With An Independently Rotating Disk On The Free End, Darrell Blaine Crimmins

Masters Theses

"This thesis provides a vibration analysis of a rotating cantilever beam with an independently rotating thin circular disk on the free end. The exact differential equations of the system as defined by classical Bernoulli-Euler beam theory are written using the methods of the calculus of variations. The exact equations are not solved, but two different approximations are found by assuming a cubic polynomial deflection curve and applying the equation of Lagrange. The solutions are restricted to small deflections of the beam and a shaft stiffness which permits a deflection in only a single plane. Nonlinear differential equations result in the …

A Digital Computer Program For Studying Elasto-Plastic Structural Behavior Due To Cyclic Loading, Rameshchandra Chandulal Hazariwala

Masters Theses

"A computer program has been developed to study the behavior of plane stress structures under cyclic loading. Such phenomena as thermal ratcheting, alternate plasticity, shake-down and the Bauschinger effect may be considered. The incremental theory of plasticity has been used. The program deals with realistic conditions such as nonlinear strain hardening, nonlinear temperature distribution and occurrence of both compressive and tensile plastic flow. The concept of an average material property has been used. Thermal ratcheting of a beam subjected to a constant bending moment and a temperature cycle has been studied in detail. The analysis shows analytically that the rate …

A Transient Method Of Negligible Internal Thermal Resistance For Determining Thermal Contact Conductance In A Vacuum, Richard Chuka Oboka

Masters Theses

"A transient method for experimentally determining the interface conductance between metallic surfaces in contact is developed. The method applies the theory of negligible internal thermal resistance of one of the materials which form the interface. The method is applicable when the interface conductance is very low, a situation which exists when low conductance interstitial materials are used between contacting surfaces for purposes of thermal isolation. In this investigation, stainless steel wire screens of 10 and 100 mesh were used as interstitial materials between aluminum surfaces in a vacuum environment of 10⁻⁵ to 10⁻⁶ Torr. The interface pressure ranged from 40 …

Effect Of Surface Conditions On Nucleate Pool Boiling Of Refrigerant-11, Abbas M. Sinnarwalla

Masters Theses

"The purpose of this investigation was to determine the effect of surface conditions on the heat transfer for nucleate pool boiling from flat horizontal surfaces. Experiments were carried out using Refrigerant-11 at atmospheric pressure as the test fluid with Inconel-600 as the heater material. The heat transfer coefficient was determined for mirror finished, chemically etched, glass beaded and sandpaper roughened heater surfaces over heat flux ranging for 0 to 18000 BTU/HR SQ FT. At a given heat flux, the heat transfer coefficient was found to be the lowest for mirror finished surface and the highest for sandpaper roughened surface"--Abstract, page …

Australian Tractor Test Report. No. 56. Zetor 5511, G H. Vasey, W. F. Baillie

Journal of the Department of Agriculture, Western Australia, Series 4

AUSTRALIAN TRACTOR TEST REPORT

The Zetor 5511 is a general purpose farm tractor. With 43 drawbar horsepower and 51 h.p. at the P.T.O. at rated engine speed it comes within Class 5 of Australian Standard Classification of Wheeled Tractors for Agricultural Purposes, A.S. Dl0-1967. It is equipped with 18.4 x 28 pneumatic tyres.

It has a five-speed gear box with a High and Low ratio change giving 10 forward and 2 reverse speeds

Super Spreader Distributes Snail Baits, G D. Rimes, W. M. O'Donnell

Journal of the Department of Agriculture, Western Australia, Series 4

THE problem of distributing snail bait on broad acres has been overcome by simple modifications to a conventional super spreader.

The Setting And Control Of Disc Ploughs, P A. Taylor

Journal of the Department of Agriculture, Western Australia, Series 4

THE trailed disc plough is the most commonly used tillage implement in Australian broadacre farming, yet it is considered in some areas to be difficult to set and to operate. These notes provide information resulting from C.S.I.R.O. research to assist operators in the control and operation of trailed disc ploughs.

How Many Acres Per Hour?, J G. Drever

Journal of the Department of Agriculture, Western Australia, Series 4

MANY farm tractor operators don't know exactly how much land is covered in an hour by implements drawn by their tractors. This information, useful on any farm where tractors are used, is of particular value in contract work.

The capacity of the machine or implement, or in other words, its rate of working, depends on the width of the machine, how fast it travels, how efficiently it is operated and the time it works.

Radiative Heat Transfer Analysis From A Heated Airport Runway To Fog, Gordon L. Scofield, Tom J. Love

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Radiative heat transfer between a plane source and an aerosol is investigated through the Monte Carlo method. Thermal energy is transferred from a long rectangular source to monodisperse natural fog models. The analysis is only for radiative transport and does not include convection which would be coupled in a complete analysis. Direct energy transfer to the droplets of the aerosol is investigated for values of extinction coefficient of 10 km-1 and 80 km-1, absorption coefficient to extinction coefficient ratios of 0·4 and 0·5, and scattering functions of the strong forward and isotropic types. Monochromatic radiation at a wave length of …

Stability Of Asymmetric Hydrodynamically Developing Channel Flows, T. S. Chen, E. M. Sparrow

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Linear stability is studied for developing channel flows induced by asymmetric velocity profiles at the inlet. Neutral stability curves and axial variations of the critical Reynolds number are presented, showing greater stability for more skewed inlet profiles.

Use Of The Turbulence Kinetic Energy Equation In Prediction Of Nonequilibrium Turbulent Boundary Layers, William Madison Byrne Jr.

Doctoral Dissertations

"A differential method is proposed for the prediction of a broad range of turbulent boundary layers of engineering and scientific interest. A digital computer program is presented which is applicable to boundary layers with positive, negative, and zero pressure gradient in the main-stream direction as well as boundary layers with suction, blowing or zero mass addition at the wall. The turbulence kinetic energy equation is solved simultaneously with the longitudinal momentum and continuity equations to provide an independent means for determining the effective viscosity which makes allowance for "history" effects in the flow. It is shown that the prediction method …

Optimizing Diesel Engine Efficiency Using The Controllability Of A Variable Ratio Hydrostatic Transmission, Gordon Wright

Doctoral Dissertations

"A linear mathematical model of a diesel engine, hydrostatic transmission, and electric dynamometer system was developed. This model was used as an aid in designing a single input controller which regulates engine speed to optimize efficiency while maintaining constant transmission output speed under changing load conditions. Compensation was necessary to stabilize the system because of positive feedback in the engine control system. The compensated system's response was compared to that which was predicted analytically. The analytical model was then extended to design the control system parameters to operate the engine and transmission in a representative vehicle"--Abstract, page ii.

An Investigation Of The Stiffness Of Shafts With Integral Disks, Richard King Riley

Doctoral Dissertations

"The results of an investigation of the effect of an integral disk on the torsional elastic stiffness of an axisymmetric shaft are presented. Various configurations of disk diameters and widths on a shaft of specified diameter were investigated, using a finite element method of calculation verified by experimentation. The finite element method is presented for the elastic solution of a general axisymmetric body under all possible axisymmetric load conditions. The axisymmetric body is idealized as an assemblage of triangular cross-sectioned torii representing both the normal and shear properties. The elastic stiffness is used to obtain the equilibrium equations of the …