Mechanical Engineering Commons^™

A Rubber Membrane Analogy For The Study Of Shafts In Torsion., Myron D. Bruns

Masters Theses

"The thesis presents a review of literature giving reference to several books which present the many and varied methods of determining the shearing stresses in shafts. However, no reference was found that used a rubber membrane analogy similar to that used in th is thesis. The theory of torsion, the membrane theory, and its analogy have been presented for a better understanding of the subject. Illustrations are used freely for clarity.

Analytical methods and solutions are given for two problems. The first method is that of writing a Saint-Venant stress function and satisfying the necessary conditions for it to be …

Use Of Sr-4 Strain Gages Under Hydraulic Pressure, Manubhai M. Patel

Masters Theses

"In this investigation an attempt has been made to determine the effects of hydraulic pressure on SR-4, type A-5 strain gages. A thick-walled aluminum alloy cylinder without end constraint was used to make an experimental study of the effects of hydraulic pressure on these strain gages.

The behavior of this cylinder under different internal hydraulic pressures was also studied by measuring the strains by means of strain gages which were attached to the inside and outside surface of the cylinder. The problem has been studied by applying pressures up to 4800 psi.

Because of the high internal fluid pressures various …

The Design, Construction, And Operation Of A Conducting Field Analog Computer., Richard T. Johnson

Masters Theses

"The purpose of this investigation is to design and construct a simple conducting field analog to solve problems described by the two-dimensional Poisson or Laplace equations. Decisions concerning choice of conducting media, construction of problem models, and design and construction of a specialized power supply with instrumentation were based on the results of previous experiments. Several problems are solved using the designed apparatus. Partial solutions to these problems are displayed in graphical form.

The greatest deviation of the experimental results from iterative values was consistently less than 8%. In most cases the deviation was less than 6%. The console arrangement …

A Study Of Rotational Critical Speeds For A Multi-Mass System By Influence Coefficients, Kantikumar G. Patel

Masters Theses

"In this investigation an attempt has been made to determine the critical speeds of a multi-mass rotational system by using influence coefficients. Modes of vibrations are also examined at these critical speeds.

A shaft carrying five masses, supported by bearings at the ends, has been studied analytically. The length of the bearings is considered small with respect to the shaft length and therefore, the configuration is assumed to be point supported as a simple beam. The five masses, each weighing one pound, were placed at equal distances of 10 inches on a 60 inch shaft. The critical speed was examined …

Minimum Frictional Characteristics Of Optimum Journal Bearings., Navinchandra F. Shah

Masters Theses

"This investigation was conducted to develop a graphical representation to determine the optimum bearing conditions for minimum friction and to establish a theoretical approach for journal bearing design.

A series of graphs has been plotted for· the coefficient of friction versus the eccentricity ratio based on the. Sommerfeld number derived from Reynolds' differential equation, f or optimum journal bearings.

The results obtained in this research have been compared with those developed by other investigators. This comparison confirms the validity of the results presented in this thesis, so that it could be used advantageously for the design of optimum journal bearings"-- …

Methods For Synthesizing A Four-Bar Mechanism So It Will Have A Low Value Of Jerk., Ronald D. Brenner

Masters Theses

"The purpose of this thesis is to find a method of synthesis, for a four-bar mechanism, so that the mechanism that is synthesized will have a low value of jerk. In the field of synthesis there has been little or no effort made to consider jerk when designing mechanisms.

Jerk is defined as the time rate of change of acceleration. Jerk can also be expressed as being proportional to the time rate of change of the inertia forces. When the jerk is large the effect on the link of a mechanism is the same as that of an impact load. …

A Study Of The Angular Velocity In A Liquid Induced By A Vortex In An Emptying Container, James Paul Hartman

Masters Theses

"Previously a limited amount of investigation has been done to describe the rotational motion of fluid in a draining tank. To date tank design has been based on trial and error, since the physical mechanisms of actual draining have not been recognized. This investigation has been made to develop a technique for the measurement of the motion of the fluid during the draining process and to present the results of the observed surface velocity of the liquid as a function of depth of fluid and its distance from the center of the vortex core. Many previous investigators of vortex behavior …

An Investigation Of Optimum Journal Bearings., Kulin Purshotam Maskai

Masters Theses

"Not much has been done towards calculating the "Optimum Bearing" from the point of view of maximum load capacity or minimum friction. It has been found that there 1 is not much difference in the "Optimum Bearing" proportions, as calculated, considering either minimum friction or maximum load capacity

Journal bearings are commonly used and they play a very important role in reducing friction and wear. Engineers use past experience in choosing a bearing for the given conditions. A bearing design can be obtained if 'Optium Bearing' proportions are calculated as suggested by Kingsbury (1) in his article on 'Optium Conditions …

A Study Of Rotational Critical Speeds For A Multi-Mass, Multi-Span System, Pravinchandra M. Upadhyay

Masters Theses

"It is well known that the unbalanced inertia forces present in rotating shafts set up violent vibrations in a transverse direction at certain speeds known as critical speeds, whirling speeds or whipping speeds. Therefore one who deals with the design of rotating machine parts, such as turbine rotors, multi-cylinder engine crankshafts etc., must consider transverse vibrations of rotating parts.

Practical solutions for finding the critical speeds of simple rotating systems, such as a single disk on a shaft with a single span, were derived by many authors. But as the number of loads and spans increases the problem becomes complex …

Investigation Of Ablation Materials, John Martyn Schattyn

Masters Theses

"The desired result of this paper is to determine what effect the physical and thermal properties of a material have on the ability of that material to act as an ablation heat shield. On the basis of their physical properties, five materials, nickel, beryllium, fused quartz, teflon, and phenolic-nylon, were chosen as examples.

The tools used for this study are heat transfer equations involving a change in material phase. The resulting criteria may be assumed applicable to any material exhibiting one of the four types of ablation processes"--Abstract, page 2.

The Effect Of Reradiation On Heat Transmission, Arvindkumar M. Shah

Masters Theses

"In heat transmission by radiation, it is very easy to find the heat transmitted from one surface to another. Much work has been done in this area. The problem becomes complicated when the two surfaces are enclosed or joined by an enclosure. Such problems frequently arise in the design of furnaces. One problem is linked with the economy of fuel, by proper consideration of heat losses through the openings in furnace walls such as doors and burner openings. A second problem is associated with the heating capacity and useful heat transfer through the openings such as heat ports in walls …

Heat Transfer Through A Honeycomb Sandwich Panel, Jayantilal J. Darji

Masters Theses

"Progress brought about by human ingenuity and technological developments has been always accompanied by fresh problems, the successful solution of which enables still further progress.

The recent developments in space exploration and exploitations are astounding. The coming years are likely to bring forth many remarkable achievements. Except for several engineering problems encountered with these developments the pace of progress is to study the heat transfer from honeycomb sandwich panels as an outer skin of high performance flight vehicles. The quantity of heat transferred through the panel is important in study of such vehicles, and methods or equations for determining this …

Analysis Of A Char-Forming Ablator, William J. Reilly

Masters Theses

"The purpose of this thesis is to conduct an analytical analysis of a char-forming ablation material. This is one phase of ablation heat transfer.

Fourier's general equation for one dimensional heat conduction is transformed to moving coordinates and is then solved using the applicable boundary conditions. Solutions of this equation are valid for initial studies in ablation heat transfer"--Abstract, page ii.

Methods For The Determination Of The Thermal Conductivity Of Solids., A. M. Sivadasan

Masters Theses

"The thermal conductivity of materials is of considerable practical and theoretical interest. Numerous publications on this subject have been presented with widely varying approaches and applications being made. Perhaps for no other thermal property are the published results so widely divergent and subject to such great uncertainty, particularly at high temperatures. This is partly due to unsolved difficulties in measurement, but perhaps to an even greater extent to the fact that the thermal conductivity of a material depends on its physical characteristics as well as some environmental factors such as humidity and temperature. In the case of metals or alloys, …

The Design, Construction, And Calibration Of A Hydrodynamic Journal Bearing Testing Machine., John H. Roberts

Masters Theses

"The purpose of this investigation was to design, construct, and calibrate a journal bearing testing apparatus. The design, construction, and operation of the apparatus are described.

Two bronze bearings with length to diameter ratios of 1.0 and 0.5 were tested using a gravity oil reed system. The speed and the location of inlet oil supply were varied, and the resulting coefficients or friction, oil flow rates, outlet oil temperatures, bearing shell temperatures, and eccentricities of the bearings were determined. These results were evaluated and compared with theoretical solutions.

The results compared favorably with the theoretical solutions and substantiated the use …

An Investigation Of A Constant Velocity Paper Unwinding Device, Jerry L. Gilmore

Masters Theses

"This thesis outlines one approach in designing a system which involves a second order nonlinear differential equation. A large number of variables are involved in this analysis. Therefore, there are many solutions to the problem but only a few of these will satisfy all required conditions. The analysis will be aided by the use of an analog computer. This computer can be manipulated to obtain optimum values for the different variables.

The computer results are presented in graphical form. Reasonable values for the different variables are obtained from these graphs.

The characteristics of the unwinding device were simulated on the …

Convective Heat Transfer In Small Enclosed Air Spaces., Joseph Charles Kroutil

Masters Theses

No abstract provided.

Parameters In Ablation Heat Sheilds, Franklin Chang Liang Lin

Masters Theses

"The desired result of this paper is a method of determining temperature distribution and burn off rate in a semi-infinite rod or shield subjected to a large heat flux. The possible methods of determination were investigated, and it was felt that an analytical approach turned out to be the most feasible.

The analytical analysis employed involves the use of the Fourier's general equation for one dimensional heat flow. Transformations from stationary to moving coordinates reduces the problem from unsteady state to steady state boundary conditions. The resulting equations can be applicable to the extent for the heat flow problems involving …

Thermocouple Shape Influence On Response In A Dynamic Compressible Fluid Atmosphere, Philip J. Steger

Masters Theses

"This investigation was performed to determine whether the geometrical shape of a thermocouple used to measure the temperature of a dynamic fluid atmosphere had any affect on its recovery factor and time response.

A converging nozzle was used to establish a dynamic fluid stream in which shaped silver solder junctions of copper-constantan thermocouples were tested. The velocity of the working fluid, air, was about 1000 ft/sec at the test point.

The investigation was successful, within experimental limits, in determining that the recovery factor of a bare thermocouple junction is not influenced by geometrical shape The results agreed substantially with available …

The Design, Construction, And Calibration Of An Apparatus To Determine The Thermal Conductivity Of Solids, Alan Edward Stephenson

Masters Theses

"Many pieces of equipment have been designed to determine the thermal conductivity of solids. They all, however, depend on the application of Fourier's equation of heat conduction in solids to determine the thermal conductivity. The apparatus used in this investigation is a modification of the guarded hot plate method used by the American Society for Testing Materials. Operation of the device is given in a step by step procedure both as a guide for others and also to show how it was operated during calibration of the apparatus. Data obtained in the calibration is given in tabular and graphical form …

A Study Of Rotational Critical Speed For A Multi-Mass System, Richard K. Brockmann

Masters Theses

"The object of this thesis is to demonstrate, by use of an IBM-1620 digital computer, a fast efficient method for locating natural frequencies of multi-mass rotational systems. Stress and deflection characteristics are examined at these frequencies also.

The shafts considered in this thesis are simply supported and symmetrically loaded with five concentrated masses. These five masses are placed at increments of 10 inches on a 60 inch shaft. The variable to be examined is shaft diameter, which is varied from 0.2 inch to 1 inch by increments of 0.2 inch. The effect of shaft weight, which is a function of …

Experimental Stress Analysis Of Bolts In A Flange Coupling, Bansidhar Shah

Masters Theses

"This thesis deals with the strength of a bolted joint which is subjected to tensile and bending loads. The purpose of this investigation was to derive expressions for the stresses developed in the bolts and the load producing separation of the joint.

A laboratory study of a flange coupling was made and the behaviour of flange bolts under different clamping forces was studied in tension and bending tests. The strain in the bolt was measured by mounting the strain gages on the shank of the bolt. From this, a graph of applied load versus strain in the bolt was plotted. …

A Survey Of The Methods Of Gas Analysis, Yadvendra V. Desai

Masters Theses

"The object of this thesis is to survey the different types of gas analyses. Subject concentration will be centered on the general and specific instrumental methods of gas analysis. A general account of continuous automatic gas analyzers will be included. References are included for the use of those who desire a more comprehensive knowledge of a specific method of gas analysis.

During recent years, the importance of gas analysis has been considerably increased with the advancement of science and technology. Gas analysis mainly involves the identification, quantitative evaluation and separation of the components of a gaseous mixture. Thus it includes …

Thermal Conductometer For Liquids, Yuan-Kai Chang

Masters Theses

"The published data pertaining to the thermal conductivity of liquids are of such a character that it is very difficult to determine from them the correct value, or the temperature coefficient for any liquid.

Most of the published values of thermal conductivity for liquids are evaluated at one particular temperature. It is the purpose of this investigation to design, construct and calibrate a thermal conductometer for liquids over a temperature range of 30°F to 200°F.

Since water and glycerol were the only liquids found by this investigator with published data on their conductivities as a function of temperature, they were …

Experimental Evaluation Of Thermal Strains And Stresses, T. F. Lehnhoff

Masters Theses

"This investigation is the study of a method for the experimental measurement of thermal strains. Using four electric strain gages (two of one type and two of another) the method will yield the normal and shear strains as well as the temperature change in any biaxial stress field. The gage types must be chosen for the range of temperature in which it is desired to measure the thermal stresses. The method described eliminates the need for extra resistors, thermocouples, unrestrained dummy gages at the same temperature as the active gages, special alloy gages for each type of metal and special …

Transpiration Cooling Of A Heat Generating Porous Plate, M. K. A. Hameed

Masters Theses

"This investigation is a continuation of a thesis by T. S. Purewal. Several of the simplifying assumptions made by the above author are either ignored or the justifiability of such assumptions is probed into in order to obtain a more rigorous solution. Effects of the assorted grain size, non-Newtonian cooling, direction of coolant flow, thickness of the porous heat generating plate, specific heat of the coolant, and compressibility of the coolant are investigated in this thesis. Variation of maximum temperature of both coolant and the solid material for different types of heat source distribution are also studied.

As the grain …

Analog Study Of Vibratory Forces In Sorting Machine, Navnit Chhaganlal Mehta

Masters Theses

"This investigation involves the study of the reduction of vibratory forces in a sorting machine. The equivalent masselastic system is shown in Figure 1, in solid lines. In this figure the mass m₁ represents the main structure for the mounting of the machine, the mass m₂ is the main bearing blocks and the mass m₃ is the vibrating basket. The elastic stiffness indicated as k₁ represents the mounting spring for the entire unit, the stiffness k₂ is that of the beam structure by which the bearing block is attached to the main structure, and the stiffness k₃ is that of …

A Study Of The Problems Of Design Of Optimum Vibration Absorbers For Multi-Mass Systems, James C. Villegas

Masters Theses

"The purpose of this investigation was to continue the preliminary work of Burrows on the application of tuned and damped vibration absorbers to the reduction of vibratory stresses in a multi-mass torsional vibration system. A hypothetical engine system was chosen for both investigations because it had many complicating factors and gave an eminently practical subject for study.

Attention was centered on the reduction of stresses resulting at higher speeds of the machine system and on developing methods and criteria for the designing of effective absorbers where several modes of vibration exist in the operating speed range of the machine"--Abstract, page …

Refrigeration Heat Transfer Characteristics Of An Artificially Cooled Trout Pond, Richard G. Murray

Masters Theses

"In many locations natural summer lake and pond temperatures are too great for the practical production of trout for fishing purposes.

The purpose of this thesis is to investigate the refrigeration capacity required to maintain a pond of water at a temperature that provides a healthful environment for trout.

The over-all refrigeration load for this application was sub-divided into four categories; conduction, convection, evaporation and radiation. Each type was solved by analytical means using suitable boundary conditions and simplifications. It was necessary to determine one boundary condition for the conduction heat transfer by an empirical method.

The results of this …

A Study Of Heat Transfer Coefficients On Cylindrical Pipe In Turbulent Flow, Dennie Lee Adkins

Masters Theses

"This thesis represents a study of the effects of turbulent motion on heat transfer coefficients on cylindrical pipe.

The turbulent motion was created by cutting transverse slots in a spiral configuration along the pipe length.

An induction heater was used for the heat source and water as the cooling medium. The water was conducted over the pipe surface and through the slots.

This caused the laminar layer along the pipe surface to be broken up and an increase in the heat transfer coefficient was experienced.

The main objective of this test was to find if a relation existed between the …