Mechanical Engineering Commons^™

Performance Characteristics Of A Tubular Regenerative Heat Exchanger, Harry J. Sauer Jr.

Masters Theses

"The term regenerator is widely used to define any type of heat exchanger in which the heat is alternately stored and removed...The present investigation is concerned with the calculation of the characteristics of the "single-blow", tubular regenerative heater, its dimensions and performance. In the analysis in this thesis, the heat is considered to be stored in bundles of tubes initially preheated by hot gases flowing through the heater and subsequently cooled by the flow of air. This paper makes no attempt to deal with the effects of radiation from the outer row of tubes to the heater shell"--Introduction, page 1-3.

Frost Formation And Its Influence Upon Heat Transfer, Jack Lewis Loper

Masters Theses

"The cooling of a gas-vapor mixture or a mixture of several vapors, in the general case, results in condensation (phase-change) of one or more of the vapors when their respective dew-points are reached. This results in a mass transfer of the vapor to the cooling surface accompanied by energy transfer as the vapor gives up its latent heat of vaporization to the surface and becomes a liquid. The liquid accumulation adds a resistance to the further transfer of mass and energy unless some means is provided for its removal from the surface, such as gravity action.

In this paper we …

Surface Temperature Measurement Of Metal Undergoing Induction Heating, Ding-Yee Nee

Masters Theses

"It is the object of this thesis to investigate the possibility of using thermoelectric pyrometry for surface temperature measurement of metal undergoing induction heating. The temperature range under investigation, as stated before, is 400 °F to 1250 °F. This research may actually be treated by two sections.

The first section concerns the methods of using thermocouples for ordinary surface temperature measurements. The second section concerns the effect, if any, on thermocouple e.m.f. readings while it is measuring the surface temperature of a metal undergoing induction heating. The first section of the investigation has been well covered by literature and will …

The Stability Of Rectangular Plates With Built-In Supports At The Edges, John Bruce Miles

Masters Theses

"The purpose of this investigation is to derive an expression for the critical stress for a thin rectangular plate with compressive edge loading. The load is applied on two opposite edges with the remaining two edges built-in. (See Fig. 1) This is essentially a stability problem.

Rectangular plates with compressive edge loading and various edge restraints appear in a number of engineering structures. Bulkheads of ships could be so classified, as could certain components of fabricated beams and columns. The new supersonic B-58 bomber developed by Convair has a honeycomb wing structure dictated by heat conduction requirements. This, too, involves …

The Closure Of Thin Wall Pressure Vessels, Archie W. Culp Jr.

Masters Theses

"The object of this thesis is to find various methods of closing thin wall aluminum cylinders. Such a closure must be strong enough, that when internal pressure is applied, ultimate failure will occur along a longitudinal element of the cylinder and not at the closure. Moreover, such a method must not only be mechanically sound, but it must be readily adaptable to mass production"--Introduction.

Heat Flow In A Two-Dimensional Steady-Flow System Without Radial Symmetry, George H. Parharoglu

Masters Theses

"As the extent of the science of heat conduction depends on the multiplicity of the boundary conditions that can be applied to the basic differential equation, a particular case in which the use of one set boundary conditions for the development of the general equation for the temperature distribution as well as the the amount of heat flow in a steady-state, two-dimensional heat flow system with a source of heat plased at the center of or along the axis of a cylinder, and without radial symmetry has been the object of this problem. Radial symmetry means the variation of temperature …

Crimp Method Of Closure Of Small Pressure Vessels, Zafiri Bersu

Masters Theses

"The object of this thesis is to design a means of closing the ends of thin aluminum alloy tubing in the 1” O.D. to 2” O.D. by .035 to .065 inch thick sizes, so that the closure will withstand internal hydrostatic pressure sufficient to burst the tube along the longitudinal element.

The aim is to approach the ultimate mechanical efficiency possible, and at the same time to keep actual production in mind.…

Summarizing the aims of this investigation, it can be said that the objectives of this investigation are:

1. To design ends for closed vessels.
2. To form the designs.
3. To …

Photoelastic Investigation Of The Stresses In A Capless Connecting Rod, Gerald Delaine Smith

Masters Theses

"For a great many years the primary method used to solve engineering problems was by the use of mathematics. However, rigorous and simple mathematical solutions are only possible if the geometry of the member and its loadings are relatively simple. When irregular shapes with complex loadings are encountered, rigorous mathematical solutions for stresses induced are either impossible or very cumbersome. In such cases, the engineer must resort to other methods which are available today.

This paper attempts to show the application of the photoelastic method to such a problem. Moreover, it will show the comparative ease with which the designer …

Effect Of Viscosity On The Cetane Number Of A Diesel Fuel, Moris Bolay

Masters Theses

"The object of this paper is to determine or rather experimentally establish the effect of a change in viscosity of a given diesel oil in regard to the ignition quality (cetane rating) of the oil.

The author did not attempt to prove why or find out how much the cetane number was affected. But, merely, tried to experimentally verify the fact that the cetane number of the fuel used underwent a change when its viscosity was decreased by preheating it.

Since his professional interests lie in the field of automotive engineering, several thesis problems were suggested to him by Dr. …

The Holding Strength Of Crimps On Tubes, Aydin Cansever

Masters Theses

"The object of this thesis is to determine by analytical means and laboratory tests the holding force of various crimp methods of fastening sheet metals and special tubing. The study is conducted with heat treated Aluminum alloy 24S.T3.

The problem of joining relatively thin walled tubing of high strength material or the application of a plug to such a tube has been investigated by many manufacturers, but the literature in this field is limited and still there are many cases where a better method may prove very useful. At the suggestion of Dr. Aaron J. Miles, the author decided to …

The Effect Of Various Binders And Moisture Content On The Apparent Thermal Conductivity Of Green Foundry Sand, Robert V. Wolf

Masters Theses

"The broad field of heat transfer is well developed in its theory and mathematics, however, some few applications of varying heat transfer rates have been explored only recently.

Previous to the nineteen-thirties, foundrymen had apparently been interested in heat transfer measurements only from the standpoint of the melting of metals and the heat treatment of the finished castings, with the rate of solidification and the transfer of heat from the casting through the mold being ignored, or at least accepted as an uncontrollable factor. This does not apply, of course, to the use of metal chills to adjust solidification rates …

Photoelastic Investigation Of Notched Corners In Square Apertures In Flat Plates Subjected To Tension, Lloyd E. Byrd Jr.

Masters Theses

"Photoelastic stress analysis is one of the most effective methods available to the engineer for solving problems of stress distribution. The effect of forces, such as pressure and tension may be studied using a scale model of a structural part. Special transparent models are subjected to forces proportional to those acting on the real object. The stress problem produced in the model indicates the stress distribution through a cross-section of the structural part.

Analysis of the photographic record of the stress analysis pattern provides data with a high degree of accuracy within a relatively short time. In simple cases, this …

Air Flow Through Cloth Screening, Kurt Rauf Basakinci

Masters Theses

"The object of this investigation is to obtain an expression whereby flow of air through woven cloth can be predicted with a reasonable degree of accuracy, in terms of the pressure drop across the screen, the density, the viscosity of the air flowing; these latter properties being functions of the pressure and temperature of the air.

The development of an expression from which to predict the relationship between the air flow through a screen and the pressure drop across it without resort to experimental procedure seems to the author to be worthwhile undertaking.

The chief aim of this investigation was …

The Effect Of Back Pressure Created By A Venturi Tube On Power Output And Efficiency Of An Internal Combustion Engine, James J. Trace

Masters Theses

"The exhaust pressure against which an engine works affects the amount of pumping losses, the volumetric efficiency and the rate of advance of the flame front during the combustion process.

When the back pressure is decreased to the same pressure as the intake pressure, the amount of negative work done during the exhaust-intake process approaches the positive work done during the process. It can be seen from a PV diagram that it is possible to make this negative work less than the positive work and gain work during the process.

Because of the "15 to 30 degrees” of intake valve …

Highway Construction And Maintenance Equipment With Machine And Automotive Repair Shops For The Reconstruction Of The Highways Of The Iv Division, Ankara, Turkey, Steve Theodorides

Masters Theses

"With the rapid advancements being made in travel and communication facilities today, the world is steadily growing smaller and people in the far places of the world are no longer strangers.

There is no doubting the importance of tractors, dozers, scrapers, power shovels, graders, bituminus construction equipment, aggregate handling, etc., in the present-day world, in aiding the progress of civilization and bringing to all people the good things of life.

It must be remembered that money expended for highways is not wasted, and can be classified as an asset.

In substance, this is a general project for the reconstruction and …

The Effect Of A Uniform Layer Of Insulation On The Temperature Amplitude In Periodic Heat Flow, Ralph E. Schowalter

Masters Theses

"The object of this thesis is to determine by analytical methods the temperature at any time within a homogeneous semi-infinite solid protected by a uniform layer of insulation, while its one and only one plane face is subjected to a periodically fluctuating temperature. The temperature at an infinite distance within the solid is to remain constant, and the heat flow in the other two directions is to be considered negligible.

Periodically fluctuating temperatures are frequent in both nature and engineering. The surface of the earth is subjected to temperature changes which are very nearly periodic, and these changes are made …

The Effect Of Inlet Air Temperature On The Efficiency Of A Spark Ignition Engine, John B. Toomey Jr.

Masters Theses

"The object of this thesis is to determine the effect of inlet air temperature on the efficiency of an internal combustion engine. In most text books the subject is dismissed with mentioning the negative effect of warm air on the maximum output of the engine. This fact is recognized but since most engines are run at maximum output only a small percentage of the time, it would be possible to control the air temperature as the situation demanded. With the assumption that cold air could be used when full power is desired, it was decided to determine the effect of …

Photoelastic Investigation Of Filleted Corners In Square Apertures In Flat Plates Subjected To Tension, Raymond Huston Bever

Masters Theses

"During recent years many advances have been made in solving engineering problems by mathematical means. While this method of solving problems is invaluable to the engineer, there are times when a rigorous mathematical solution cannot be readily obtained, and the engineer must resort to other methods, some of which are approximate.

This paper attempts to show the application of photoelastic investigation to such a problem. The results of this problem are quantitative, but they show without any doubt that this method of investigation has considerably influenced the modern design of machine parts and helped in many cases to improve construction …

Analytical Investigation Of Bending Effects On The Stability Of A Tube Subjected To External Pressure, Charles Young

Masters Theses

"The behavior of thin and moderately thick-walled tubes under various types of loadings has been a major problem of several leading industries for many years. Predominant among these, and the one for which this thesis was primarily undertaken, is the oil industry. The problem attacked in this thesis, however, is not limited to that industry alone, having ample application in industries that are sub-marine in nature, or any industry in which the application of external pressures on equipment is likely to be responsible for buckling failures...In this thesis, the problem of finding the effect of bending on the collapsing pressure …

Hydraulic Scale For Measurement Of Dynamometer And Other Forces, John Richard Barton

Masters Theses

"The object of this investigation is to design, build, test, and develop, a hydraulic type scale primarily to be used for measuring dynamometer forces. The scale however is not limited to use on dynamometers, but may be used for other types of force measurements such as the continuous weighing of material on a conveyor belt in conjunction with a recording pressure gage. The scale has numerous applications in determining forces where conventional scales are now used. This particular subject was chosen because of the need for a convenient, inexpensive, and accurate scale for use in measuring the force exerted by …

Periodic Heat Flow In A Semi-Infinite Solid, Warren George Heidbrier

Masters Theses

"The object of this investigation is to determine by analytical means the temperature within a homogeneous semi-infinite solid, as a function of time, while the solid is receiving heat periodically by radiation on its one flat surface. Periodic heat flow means that heat flow is a continuous function of time and repeats itself at regular intervals. A semi-infinite solid has only one bounding plane and extends to infinity in all other directions...Much of this work deals with the soil temperatures of the earth both at the surface and at various depths. The surface of the earth is subjected to daily …

The Temperature Within A Homogeneous Plate Of Finite Thickness, Charles R. Remington

Masters Theses

"The object of this thesis is to determine by an analytical method the temperature within a homogeneous plate of finite thickness subjected to a constant temperature on one side and a periodic fluctuating temperature, expressible in a Fourier series, on the opposite side. This problem in periodic temperature changes has not, to the author's knowledge, been solved previously. The flow of heat in the problem is considered in only one direction, the x-direction. Flow in the other two directions is considered negligible, or zero. Periodic temperature changes in the earth are of importance. The temperature changes have been used by …

The Application Of The Relaxation Method To The Solution Of Steady-State Heat Transfer Through A Concentric Square Insulator, William Edward Simpkin

Masters Theses

"It is the object of this thesis to express the relationship between the heat transfer through a square insulator of variable inside-outside dimension ratios, in terms of a concentric round insulator of the same inside-outside diameter ration, by means of a continuous curve. Mathematically speaking, this thesis will have a plot of a variable coefficient, c_s, to be used...in terms of the ratio of the width of the outside square to the width of the inside square"--Statement of Problem, page 8.

Temperature Fluctuations Within A Solid Of Finite Thickness, William Sanford Hogan

Masters Theses

"The object of this thesis is to determine by analytical methods the temperatures within a homogeneous plate of finite thickness subjected to a constant temperature on one side and a periodically fluctuating temperature on the opposite side. The heat flow in the other two directions is considered negligible in this problem. Periodic changes of temperature are frequent in nature and in engineering. The surface of the earth is heated periodically by the sun in its daily and annual cycle and the periodic temperature changes below the surface and the question to which depth these changes are appreciable were dealt with …

Torque-Stress Relations In Bolts With National Fine Threads, Eugene Casper Chase

Masters Theses

"Stresses, in bolts, caused by initial tightening have long been a problem to machine designers. To take care of these unknown stresses, produced by initial tightening, designers have used empirical formulas. These formulas originally used for National Coarse Threads, have been carried over into the field of National Fine Threaded bolts. No known tests have been conducted to determine whether or not these formulas hold in the initial tightening of Fine Threaded bolts. Initial tightening stresses may be caused by one of two ways. First, consider two flat ground plates to be held together by bolts to form a steam …

A Determination Of The Economic Feasibility Of Producing Marginal Gas Wells, Horace Tharp Mann

Masters Theses

"The purpose of this investigation is to show that it is economically feasible to produce marginal gas wells in such a manner that all the gas from the edge of the field will be captured by the first row of wells. In this problem the permeability of the sand is to be variable but known, and the effects of this variable permeability on the pressure distribution, and resulting gas production, will be discussed.

In many gas fields the point at which it is generally considered unprofitable to drill new wells is well inside the boundary of the reservoir. This is …

Water Injection In The Modern Automotive Spark Ignition Engine, Leonard Carl Nelson

Masters Theses

"The injection of water in the spark ignition engine is not new. The effect of humidity in the air on the performance of the spark ignition engine probably initiated the early investigations. The water vapor in the inlet air decreases the speed of the flame front and necessitates spark advance to assure maximum power and maximum efficiency. Water particles in the air evaporate during the compression and combustion of the inducted charge and decrease the tendency of the engine to detonate. These effects are very evident when operating the spark ignition engine in a moist atmosphere. Water is not a …

The Application Of The Relaxation Method To The Solution Of Problems Involving The Flow Of Gases Through Porous Media, Ralph Davis

Masters Theses

"The purpose of this investigation is to determine the feasibility of applying the relaxation method of mathematical analysis to the solution of problems involving the flow of gases through porous media. The relaxation method was first applied to two-dimensional problems by Christopherson and Southwell, who applied it to problems in stress analysis. It was later applied to steady-state heat conduction problems by H. W. Emmons and to steady-state flow of incompressible liquids by A. A. Zwierschowski. The solutions of problems involving the flow of gases through porous media is difficult for all but the simplest boundary conditions, and impractical for …

The Application Of The Relaxation Method To The Solution Of Problems Involving The Flow Of Fluids Through Porous Media, Alexander Antoine Zwierzchowski

Masters Theses

"The purpose of this investigation is to determine the feasibility of applying the relaxation method of mathematical analysis to the solution of problems in rheology. The relaxation method was first introduced by R. V. Southwell who applied it to the problem of electrical conductivity. It was later used by M. W. Emmons to solve two-dimensional heat conduction problems. The steady-state flow of fluids through porous media can be difficult or impossible by the usual analytical methods even with rather simple boundary conditions. The relaxation method promises to provide an easier method of solution and to provide a means of solving …

Torque Characteristics Of High Speed Steel Twist Drills, Tien Chi Lee

Masters Theses

"The drill is the most efficient tool used by machinists, for in no other tool is the cutting surface as large in proportion to the cross sectional area of the body or part that is its real support. Drills have shared evolutionary developments from carbon steels to high speed steels and from flat to twist drills. Many investigations have been made on the twist drills, but due to the majority of their work being based on the size of drills from 1/2 to 1-1/2 inches or larger, there is a dearth of published data on the general problem of drills …