Mechanical Engineering Commons^™

Effect Of Sweeping Sinusoidal Excitation On Nonlinear Dynamic Systems., Md. Mosharraf Hossain

Masters Theses

"The response of viscous damped, cubic spring systems to excitations having exponentially varying frequency cannot be written in a closed form. This report summarizes a numerical investigation of hardening and softening cubic systems influenced by these excitations and provides information concerning the effects of varying viscous damping, system nonlinearity, and excitation sweep rate on system behavior near resonance. Results are reported in terms of maximum response attained during sweeping and the frequency at which maximum response occurs.

It has been found that if hardening cubic systems are subjected to sweeping excitations wherein the frequency sweeps down through resonance, the maximum …

Design Of A Medium Pressure Hydraulic Coal Mining Machine Power Unit System., William Rudolph Heincker

Masters Theses

"In this thesis the design of the major components of a medium pressure hydraulic coal mining machine is presented. The machine is to produce water jets operating at a continuous pressure of 10,000 psi with a total flow rate of 47.8 gpm. This machine is being used to mine coal from an underground longwall coal face, with an expected output of 7 tons per minute.

The primary elements of the hydraulic coal mining machine are the power source, the pump, the cutting head, and the secondary plow supporting structures. The power source will be a British Jefferey-Diamond (BJD) Supermatic electric …

Two-Dimensional Radiative Transfer In Semi-Infinite Isotropically Scattering Medium., Thomas Lee Linsenbardt

Masters Theses

"Two-dimensional radiative transfer in a semi-infinite medium has been investigated. The medium was considered to be homogeneous, absorbing, non-emitting, and isotopically scattering. Cosine, step, and finite strip variations of collimated and diffuse incident radiation were considered. Collimated incident radiation was restricted to lie in planes perpendicular to the direction of its spatial variation.

Expressions for source functions, fluxes, and intensities at the boundary and inside the medium were obtained by assuming cos foe varying incident radiation. This assumption allowed the two-dimensional problem to be reduced to a one-dimensional integral equation for the source function. This integral equation vias transformed into …

Two-Dimensional Radiant Interchange In A Non-Isothermal Cavity Formed By Two Semi-Infinite Parallel Plates., Robert David Allen

Masters Theses

"Two-dimensional radiant interchange between non-isothermal, gray diffuse surfaces with non-uniform radiosity have been investigated for a cavity formed by two semi-infinite parallel plates. The problem is solved for two specific emissive power distribution models. Both emissive power distributions decay exponentially with depth into the cavity. The first emissive power distribution varies in a cosine manner across the front of the plates and the second has a step variation across the front of the plates.

For the cosine varying model, separation of variables and Ambarzumian's method are applied to obtain an integro-differential equation for the radiosity inside the cavity, an integral …

Development Of A Four Channel Cloud Nucleus Spectrometer., Larry Allan Brunner

Masters Theses

"A four-channel vertical flow thermal diffusion chamber for use as a cloud nucleus counter is described. The droplets in each channel are photographically counted. The instrument provides about 20 seconds of available growth time, which enables better distinction of active droplets than does ii the conventional horizontal chamber. Droplet growth calculations show that the uncertainty in droplet count due to limited available growth time is negligible for supersaturations above 0.3% but increases rapidly as the supersaturation is lowered below 0.3%. For example, at 0.1% supersaturation, the uncertainty is -27% to +38% in the drop count. The possible error in supersaturation …

Application Of An Inverse Heat Conduction Technique To A Simulated Injection Mold., Noel Joy Rytter

Masters Theses

"An analytical model was constructed to investigate the heat transfer in an injection mold for which the temperature was controlled by a special mold heating-cooling process. Several techniques were used to test the validity and accuracy of the analytical model of the mold and to explain some singularities that occurred. It was determined that the thickness of the plastic part being molded is the primary factor affecting the minimum cycle time for the molding operation. Also, abrupt changes in temperature on the molding surfaces are very difficult to obtain because this requires drastic temperature changes for the working fluid that …

Thermal Fragmentation Of Rock - The Influence Of Temperature Dependent Material Properties., James Dale Scheller

Masters Theses

"This investigation is concerned with a thermal rock fragmentation system employing heat to create subsurface thermal inclusions. The effectiveness of this system as applied to three different rock types is studied. The rock types are Dresser basalt, Charcoal gray granite, and Sioux quartzite. Also, the influence of temperature dependent material properties is investigated.

The actual three-dimensional problem of in situ rock fragmentation involves parallel rows of equally spaced holes drilled to a constant depth. A heat source at the bottom of each hole creates a thermal inclusion resulting in a stress field causing fracture.

Axisymmetric models of the fragmentation system …

Liquid Metal Heat Transfer In Longitudinal Flow Along A Cylinder And Flat Plate., Marvin Eugene Lohmann

Masters Theses

"In this investigation an analytical study is performed to determine the effect of axial heat conduction on laminar forced convection for longitudinal flow of liquid metals along a horizontal cylinder and a flat plate. ii

The flow and thermal boundary layers for the problems under consideration do not admit similarity solutions, the non-similarity arising from the transverse curvature; ε = (4/R) (vx/u _∞) ^½ of the cylindrical surface and from co the effect of the axial heat conduction expressible as Ω = 1/Pe_x , where Pe_x is the local Peclet number. The governing conservation equations along with …

Predicting Natural Frequencies Of A Hydrodynamically Lubricated Journal Bearing With Constant Oil Supply Pressure., Dennis Charles Edwards

Masters Theses

"The analytical and experimental investigations presented here determined natural frequencies and system behavior of a full journal bearing loaded dynamically and with oil supply pressure held constant.

The analysis showed that the bearing could be viewed as two independent second-order systems acting perpendicular to each other. This yielded an underdamped bearing for ε_O < 0.5747 and an overdamped bearing for 0.655 < ε_O < 0.675. The analysis also showed the bearing to be unstable beyond ε_O = 0.675.

The analysis, however, is limited to a full journal bearing with an oil supply pressure of 20 psig. and therefore, various supply pressures should be tested to yield an overall analysis"- Abstract, p. ii

Combined Forced And Free Convection On A Vertical Cylinder And Flat Plate, Aleksandros Mucoglu

Masters Theses

"In the study of fluid flow over heated surfaces, it is customary to neglect the effects of buoyancy force when the flow is horizontal. However, such a practice is not justified when the forced flow is along an inclined or a vertical surface, because under these conditions the buoyancy force modifies considerably the flow field and hence the heat transfer rate from the surface. Such a flow is termed combined forced and free convective flow.

The present study is concerned with the effects of buoyancy force on forced convection along an isothermal vertical cylinder and a flat plate. This type …

Flow Field And Heat Transfer For Developing Flow Of Molten Glass In A Duct, Russell Ralph Beckmeyer

Masters Theses

"The molten glass flow (temperature range 1300 to 1500°C) in the entrance region of a duct was investigated with numerical methods. The mathematical model was restricted by assuming: (1) two dimensional, steady state, (2) Newtonian fluid, variable viscosity, and (3) Rosseland approximation. In addition, appropriate use was made of the fact that the Reynolds number is small and the Eckert number is very small. The inclusion of temperature dependent viscosity and a Rosseland approximation for radiation produced from the mass, momentum, and energy equations a system of coupled, nonlinear, partial differential equations which were solved by an iterative finite difference …

Laser Holographic Interferometric Investigation Of Heat Transfer About An Isothermal Vertical Flat Plate, Richard Michael Quinlisk

Masters Theses

"A study of the laser holographic interferometer was conducted to compare heat transfer data obtained with the device to standard free convection boundary layer theory. The system studied was an isothermal vertical flat plate. The interferometer was used to obtain fringe patterns of the boundary layer at the plate surface.

Data from the holographic interferograms were recorded by making conventional two-dimensional photographs of the holographic images.

The optical data are shown to have a good correlation to Von-Karman theory. Values of the boundary layer thickness, temperature distribution, and heat transfer were compared. An attempt was made to probe the boundary …

Two-Dimensional Radiative Transfer In A Finite Scattering Mediu, James Warren Koewing

Masters Theses

"Exact formulations are presented for the source function, intensity and flux for a two-dimensional, isotropically scattering medium of finite thickness. Spatially varying collimated and diffuse radiation of the following types are incident on the medium: (1) cosine varying, (2) semi-infinite step, (3) step at the origin, and (4) finite strip. The solutions for the cosine varying collimated boundary condition are used to construct solutions for the other boundary conditions. The two-dimensional integral equations are reduced to one-dimensional equations by separating variables. Through a series of transformations, the one-dimensional equations are put into a form in which the source function, intensity …

Diurnal Solar Heating And Cooling Of A Water Reservoir, Stephen Patrick Lepper

Masters Theses

"The transient diurnal heating of a water reservoir by solar radiation; and its cooling by surface convection, evaporation, and radiation emission was analytically modeled. The directional and spectral properties of the incident solar radiation, the air-water interface, and the selective attenuation of radiant energy by the water were properly included in the analysis. The diurnal vertical temperature distribution was predicted by numerically solving the energy equation using a finite difference technique. It was determined that the surface boundary conditions and the selective absorption of radiant energy by the water strongly influence the thermal stratification of stagnant water.

The diurnal compensating …

Experimental Analysis Of V-Belt Tensile Loads, John Mark Wiesehan

Masters Theses

"An experimental investigation was conducted to determine the magnitude of v-belt stresses in automotive drive situations. A constant tension belt test apparatus was designed and fabricated using a variable speed cradled D.C. motor for power and two automotive alternators for absorption.

Free span stresses on the dynamic torque loaded belt drive were determined from the equations governing a pivoted drive system. Centrifugal stress was determined by a theoretical analysis of belt motion. Bending stresses were obtained from a static test employing strain gages mounted on the top of belts with exposed cord layers. The variation in load stress around the …

A Digital Simulation Of A Single Articulated Rotor Helicopter, Joseph William Klahs Jr.

Masters Theses

"The investigation was concerned with the development of a complete digital computer simulation of a single articulated rotor helicopter. The simulation program was executed on an IBM model 360-50 digital computer.

The main rotor was analyzed by the consideration of a continuous rigid blade at six azimuth stations, while the airframe aerodynamics were treated in the conventional manner. The differential equations of motion of the airframe were solved in a step-wise fashion by approximating time dependent functions with cubic interpolation polynomials.

The study concluded that there was strong evidence that suggested the possibility of treating main rotor flapping as a …

Interior Noise In Military Helicopters, Charles E. Perez Jr.

Masters Theses

"The Temporary Threshold Shift (TTS) or temporary hearing loss caused by excessive interior noise in military helicopters results in a critical degradation of the acoustically unprotected infantryman's ability to detect the existence or the approach of the enemy by hearing under combat conditions. The overall problem of noise reduction in helicopters consists of: (1) identifying the various noise sources, and (2) employing appropriate noise control techniques. Identification of the source is accomplished by the frequency correlation of 1/10-octave band analysis of the interior sound levels measured within the helicopter cabin with near-field sound generated by the sound sources. Reduction of …

An Experimental Analysis Of Oil Spill Drift Caused By Water Waves, Jan Michael Pottinger

Masters Theses

"A study was conducted to determine the effect of waves on oil spill drift. The investigation was performed in a long narrow tank equipped with a mechanical wave generator at one end and a beach to suppress wave reflection at the other end. It was found that a special procedure for taking data was necessary in order to assure that the data was consistent and that the waves were indeed deep water waves, and therefore similar to open ocean conditions.

The data indicated that waves do influence oil spill movement, and the velocity of the oil was found to be …

Analysis Of Interferometric Holography In Temperature Measurement, Allan James Reifel

Masters Theses

"An experimental investigation was conducted to evaluate the accuracy and sensitivity of a laser holographic interferometer. Interference fringe patterns of a free convection boundary layer on the surface of a vertical test plate were produced. The plate was heated and designed to produce a linear temperature distribution along its surface.

A thermocouple probe was used to map the temperatures in the boundary layer and these values were compared to temperatures obtained from fringe patterns. Data photographs of the holograms were used in the analysis. The number of fringes obtained were compared to predictions of the Gladstone-Dale Law.

High quality fringe …

Design Of A High Pressure Fluid Intensifier, James Andrew Kwiatkowski

Masters Theses

"In this thesis the design of the major components of a high pressure intensifier is presented. The machine is a high pressure fluid intensifier which can develop an intermittent water jet of .01112 inches in diameter at a pressure of 100,000 psi and a flow rate of .9508 gpm. This machine can be used to study the capabilities of high pressure water jets to cut high compressive strength rocks.

The primary machine elements of the intensifier system are the source, charging system, valve system, nozzle, and the intensifier. The source will be a Kobe Triplex Pump having a variable output …

An Experiment To Determine The Coupled Unidirectional Effect Of Wind And Waves On Surface Drift, Rameshchandra C. Shah

Masters Theses

"An experiment was conducted to study the coupled parallel and unidirectional effect of wind and waves on surface drift velocity of oil lenses and flexible plastic floats. The experiment was also conducted to study the effect of float width, wave length and air turbulence on the drift velocity of the surface floats. Experiments were also conducted to determine the air flow characteristics of the wind tunnel test section.

Experimental results are presented for a free stream wind velocity from zero to 700 cm/sec; the wave steepness ranged from zero to 0. 069, which is near the maximum steepness for stable …

Approximate Normal Mode Method To Determine The Response Of Certain Nondiagonalizabel Vibratory Systems, Jayaram Seshadri

Masters Theses

"An approximate normal mode method is developed which permits certain normally nondiagonalizable, nonconservative systems to be solved by superposition of uncoupled coordinates.

An approximate solution for a nonproportionally damped, multi-degree of freedom system is obtained by using a perturbation technique. The system is then reduced to a proportionally damped system by means of a modification to the damping factor so that the effect of the off-diagonal terms of the modal damping matrix is included. This modification produces a damping matrix that can be diagonalized by the normal mode technique. An approximate criterion is used for the determination of the modified …

Thermal Radiative Properties Of A Semi-Infinite Absorbing-Emitting And Isotropically Scattering Medium, Tung-Ting Lam

Masters Theses

"The development and the approximate solution to the transport equation for a semi-infinite, absorbing, and isotropically scattering medium with a refractive index other than unity is presented. The general boundary condition of diffuse and collimated incidence at the interface with emission from the medium was considered by superimposing the individual effects. In each case the apparent properties, directional and hemispherical emittance, reflectance and transmittance, were evaluated as a function of the scattering albedo and the refractive index.

An exponential kernel substitution was developed and used to obtain the approximate solution. The method was evaluated by a comparison with existing but …

Transmission Measurements Through Liquids In A White Cell, David Earl Hurley

Masters Theses

"The suitability of using the White cell for determining the extinction coefficient of liquids was examined by measuring the attenuation of electromagnetic radiation, in the visible part of the spectrum, through distilled water. The analysis of the transmittance measurements through liquids in a White cell does not provide a sufficient number of independent equations to solve directly for the extinction coefficient. Reasonable estimates however can be made by employing a correction which accounts for changes in the mirror reflectance due to a liquid-mirror interface.

The reduction in the transmittance of distilled water due to an oil film was studied for …

On The Complex Index Of Refraction Of Bulk Materials, Carol Jeanne Warren

Masters Theses

"As a part of the investigation of classical reflectance, it is determined that the hemispherical reflectance for a material with a particular pair of optical constants can be approximated by computing the angular reflectance at sixty degrees, using Fresnel's generalized reflectance formulas.

Reflection methods for the purpose of determining the optical constants of a variety of materials are discussed. The unpolarized reflectance versus angle of incidence technique is used for determination of the optical constants of bulk solids. Restrictions on the simultaneous solution of the Fresnel equations are determined and a computer program is developed to compute values necessary to …

Nucleate Pool Boiling Of Refrigerant-Oil Mixtures From Tubes, R. L. Dougherty

Masters Theses

"This experimental investigation was conducted to provide design heat transfer data for applications involving the nucleate pool boiling of Refrigerants 11 and 113 from the external surfaces of tubes. Tests were conducted with 0.625-in. o.d. and 1.125-in. o.d. commercial copper tubing; at 1 and 2 atmospheres pressure; and with refrigerant-oil compositions from 0 to 10 percent oil by weight. Results show that each of these parameters can affect the heat transfer coefficient"--Abstract, page ii.

Parametric Analyses Of Regenerative Steam Power Cycles, Vallabh Vithalbhai Vaghani

Masters Theses

"This study analyzes the effect of inlet pressures, internal turbine efficiencies, pump efficiencies, extraction pressures and number of open feedwater heaters on the thermal efficiency of regenerative steam power cycles. Combinations of inlet and extraction pressures were introduced into digital computer programs in order to find the optimum extraction pressures for maximum thermal efficiency. The scope of study covered regenerative steam cycles with one, two, three, four, and five open feedwater heaters. One of the principle objectives of the study was to determine if there is some turbine extraction pressure or set of pressures which give maximum thermal efficiency for …

Measurement Of Turbulence In An Annular Jet, George Philip

Masters Theses

"An experimental investigation was conducted for an annular jet which consisted of a circular jet and a concentric wake. The annular air jet mixed with quiescent atmospheric air. The jet velocity was kept constant at 137.0 feet per second which corresponds to a Reynolds Number of 73,200. Using the technique of hot-wire anemometry, mean velocities, turbulence intensities and Reynolds stresses were measured in the longitudinal and lateral directions. Two distinct flow regimes, the free stream jet regime and the diffusing jet regime, are observed. In the free stream jet regime, higher turbulence intensity and shear stress occur in the inner …

The Analog Simulation Of Heat Transfer Devices For The Smoothing Of A Fluctuating Fluid Temperature, Le Thai Son

Masters Theses

"Equations are written to describe a heat exchanger with electrical energy input and also a large tank system which can have electrical energy input. The output temperatures were sampled and fedback to define the energy input to the two systems. These systems were simulated on an analog computer and the ability of the two systems to smooth a fluctuating temperature input was tested. The testing of the systems included trying different types of controllers in the control system as well as different size tanks for the tank system. A satisfactory smoothing of the output temperature was demonstrated after some modifications"--Abstract, …

An Engineering Analysis Of Fluid Amplifiers And Development Of An Air Velocity Sensor, Gian Sagar Aneja

Masters Theses

"Fluidics, the new control technique finds its use amongst the conventional electronics and pneumatics due to some of its impressive features. Selected literature about bistable and proportional amplifiers has been presented for better understanding of the element behavior. Sensors; typical applications of fluidics have been described separately. An air flow velocity sensor has been set-up. Basically it consists of a cylinder placed across the air flow that sheds vortices in the wake due to 'Von Karman Vortex Street' phenomenon. The frequency of vortices gives a measure of velocity. The velocities obtained from the sensor have been compared to the ones …