Engineering Commons^™

Design And Construction Of A Drop Generator For Use In A Vertical Wind Tunnel, Danny Ray Conner

Masters Theses

"A drop generator, based on the principle of a vibrating capillary, was designed and built for use in the UMR vertical atmosphere wind tunnel. The drop generator worked very well on a test stand where it was firmly supported, but was not consistent when tested in the wind tunnel. Vibration of the wind tunnel walls and a slight turbulence near the forward edge of the generator caused an oscillation in the position of the stream of drops. The oscillation resulted in some of the drops hitting the edge of the collector cup, where the drops would accumulate until a large …

Test 1093: Ford 7000 Diesel (Also Ford 7000 Row Crop Diesel) 8-Speed, Nebraska Tractor Test Lab

Nebraska Tractor Tests

EXPLANATION OF TEST REPORT

GENERAL CONDITIONS

East tractor is a production model equipped for common usage. Power consuming accessories can be disconnected only when it is convenient for the operator to do so in practice. Additional weight can be added as ballast if the manufacturer regularly supplies it for sale. The static tire loads and the inflation pressures muse conform to recommendations in the Tire Standards published by the Society of Automotive Engineers.

PREPARATION FOR PERFORMANCE RUNS

The engine crank case is drained and refilled with a measured amount of new oil conforming to specifications in the operator’s manual. The …

An Analytical Study Of A Confined Viscous Vortex, David Edward Crow

Doctoral Dissertations

"A composite solution for the flow field of a three dimensional, incompressible laminar, viscous vortex confined inside a conical converging nozzle is presented. This model is used to study the strong mainstream boundary layer interaction that occurs in confined vortex flows. The confined vortex flow field is divided into mainstream and boundary layer regions. A particular class of solutions of the general equations of motion is used to represent the vortex flow in the mainstream region. That is, the tangential velocity in the mainstream region is assumed to be of the form W = T(e)/R. Velocity and pressure profiles from …

Modal Truncation Of Substructures Used In Vibration Analysis, Suresh Kumar Tolani

Doctoral Dissertations

"The objective of this study is to describe in a unified manner a group of structural dynamics analyses using the substructures technique. An additional effort is to provide a consistent basis for the selection of substructure principal modes as required by this method. Substructure principal mode frequency roots and strain energy are two criteria evaluated for the selection of substructure principal modes. System eigenvalues and system strain energy are investigated for the comparison of results in the principal modes. System strain energy should provide more rational results since it is proportional to the stress times the strain in the system …

Determination Of Thermal Contact Resistance Between Metals Using A Pulse Technique, William Edward Stewart Jr.

Doctoral Dissertations

"This dissertation reports the results of an experimental and analytical investigation to determine the thermal contact resistance of several metal specimen pairs using a relatively new pulse technique. Metal specimens were aluminum 2024-T3, aluminum 6061-T6, aluminum 7075-T6, copper 110, stainless steel 304, molybdenum, and Armco iron. Thermal contact resistance was also determined for dissimilar metal specimen pairs of aluminum 6061-T6 - copper 110 and aluminum 7075-T6 - copper 110. Aluminum 7075-T6, copper 110, and stainless steel 304 specimens were tested to determine the variance of contact resistance with time after loading.

Specimens were circular cylindrical disks between .033 and .061 …

An Experimental Investigation Of The Effects Of Ambient And Heated Steady Flow And Intense Sound Levels On The Response Of Acoustic Filter Elements, Raymond H. Schaffart

Doctoral Dissertations

"The primary purpose of this research was to investigate the effects of flow and finite amplitude waves on the response of acoustic elements. A further purpose was to evaluate the effects of elevated temperatures and cross-sectional dimensions on element performance. As an integral part of this work various laboratory techniques were explored for their suitability.

Empirical models for the acoustic impedance of side branch resonators were developed for the two operational modes, i.e., flow past the resonator and finite amplitude wave inputs. A description of the complex variation of the acoustic resistance of the resonator with flow past and variable …

Theoretical And Experimental Study Of Explosive Closures Of 6061-0 Aluminum Pipes, Lyle E. Edwards

Mechanical Engineering ETDs

This thesis examines the use of explosives to collapse metal pipes from an applications point-of-view. A particular system is studied, both theoretically and experimentally, in order to facilitate the future design of such closures with the least possible physical testing. The calculations are based on a rigid-perfectly plastic model of the observed deformations of the tubes, and on various assumed am derived properties of the metal and sheet explosives under the dynamic conditions of closure. A computer program has been devised which simulates the actual motion of a pipe during collapse. Experimental work involved actual test firing of aluminum cylinders …

Computer Solution To Inverse Problems Of Elliptic Form: V²U(X,Y) = G(A,U,X,Y), Frederick Alvin Jeter

Dissertations and Theses

One important aspect of our present age of monolithic high speed computers is the computer's capability to solve complex problems hitherto impossible to tackle due to their complexity. This paper explains how to use a. digital computer to solve a specific type of problem; specifically, to find the inverse solution of a in the elliptical equation V²U(x,y) = g(a,U,x,y), with appropriate boundary conditions. This equation is very useful in the electronics field. The knowns are the complete set of boundary values of U(x,y) and a set of observations taken on internal points of U(x,y). Given this information, plus …

The Effect Of Variable Properties On The Laminar Flow Of Gases, Norman Shilling

Dissertations

The problem of heat transfer in laminar flow of a gas through a constant diameter cylindrical tube is treated. The gas is cooled by the tube walls held at constant temperature. Two tube inlet conditions are considered: (1) fully developed velocity and uniform temperature profiles (Graetz boundary condition) and (2) uniform velocity and temperature (UTV) profiles. Results of the theoretical and experimental phases of the work are presented.

The theoretical solution is based on the compressible boundary layer equations with varying transport and thermodynamic property terms retained. For the Graetz condition, an existing finite difference solution scheme is modified for …

A Time Domain Deconvulution Technique For The Correction Of Transient Measurements., Larry Wayne Bickle

Mechanical Engineering ETDs

Techniques for correcting transient measurements can be considered as "deconvolving" or solving the convolution integral equation

R(t)=F(0) * C(t) + ∫t_0 C(t- Τ) [dF(T)/dT] dT

for the input, F(t), given the response, R(t), and response of the measurement system to a step input of unit magnitude, C(t). Because the deconvolution process is mathematically ill conditioned, it is usually necessary to place additional constraints on the functions F(t), C(t) and/or R(t).

In this paper, a numerical time domain deconvolution

(TDD) technique that provides physical insight into the problems of correcting transient measurements is presented and compared to techniques that have previously …

Dynamic And Thermal Studies Of Micron Size Metallic Particles In A Nonequilibrium Low Pressure Argon Plasma Jet, Barry R. Maxwell

Mechanical Engineering ETDs

Dynamic And Thermal Studies Of Micron Size Metallic Particles In A Nonequilibrium Low Pressure Argon Plasma Jet

Combined Thermal Weakening And Mechanical Disintegration Of Hard Rock, George Bromley Clark, T. F. Lehnhoff, Gary F. Fenton, M. R. Patel, Jaw K. Wang, Vernon Dale Allen

Mining Engineering Faculty Research & Creative Works

This investigation of the combined effects of thermal weakening and mechanical disintegration (thermomechanical fragmentation) was initiated with a view toward better understanding of the processes required for more rapidly and economically fragmenting or excavating hard rock. Boring machines for utility tunnels, transportation tunnels or mining operations may be able to utilize the advantages of processes such as thermomechanical fragmentation. Secondary fragmentation or rock crushing processes also can conceivably employ the data obtained from this study.

A New Technique For Steady State And Transient Analyses Of Incompressible Flow Networks, George V. Catanzaro

Theses

A new technique for the calculation of the transient or the steady-state mass flow rate and pressure distribution in incompressible flow networks is presented. Employing the matrix method of network analysis, the nodal continuity and branch momentum equations are solved simultaneously to obtain explicit relations giving the unknown nodal pressures and branch mass flow rates. In this manner, the transient or the steady-state behavior of incompressible flow networks with arbitrary configuration having nodal sources and sinks as well as branch transducers can be determined. In contrast with the conventional steady-state network analysis methods, the new technique can be extended to …

Direct Design Of A Portal Frame, Angel Fajardo Ugaz

Dissertations and Theses

This investigation was undertaken to develop plastic design aids to be used in the direct design of optimum frames. It uses the concept of minimum weight of plastically designed steel frames, and the concept of linear programming to obtain general solutions. Among the special characteristics of this study are: A. The integration of both gravity and combined loading conditions into one linear programming problem. B. The application of the revised simplex method to the dual of a parametric original problem. C. The application of A and B above in the development of design aids for the optimum design of symmetrical …

Strain Measurements At Extremely High Temperatures Using Moiré Fringe Techniques., Joseph W. Neudecker Jr.

Mechanical Engineering ETDs

A new procedure is described for using the moiré-fringe technique to measure strains in structural materials at temperatures exceeding 1300 °C. The principal factor found to be necessary for successful viewing of moiré patterns at extremely high temperatures is the use of reflected laser light for viewing the strained grid on the material. This factor is extensively discussed and experiments are described in which strain measurements were successfully made on graphite specimens at elevated temperatures. It is concluded that the techniques described constitute a more feasible method of measuring strains at higher temperatures than is possible by any other known …

A Study In The Design And Development Of A Baseball Pitching Machine, Neal M. Lundwall

Theses and Dissertations

Throughout history man has had the need of services which require great skill or tremendous strength or delicate consistency on the part of those who perform. Much of the time he has turned to the machine to accomplish these requirements.

Transition From Laminar To Turbulent Flow For A Two-Phase Mixture, Mohammed Sharief Qureshi

Theses and Dissertations

A phase is simply one of the states of matter. Multiphase flow is the simultaneous flow of several phases. Two-phase flow is the simplest case of multiphase flow.

A Computer Simulation Of A Partial Venous System Of A Human Lower Extremity, David C. Smith

Theses and Dissertations

The human body is truly a fascinating and complex creation of our Maker. Because of the complexity and variability, many of its workings were little known until recent years. Some of the more amazing facts of the circulatory system follow. If the individual blood vessels of a single adult, i.e., artery, arteriole capillary, venule and vein, were laid end to end, they would extend more than 60,000 miles. For the average adult, the heart beats 70 times per minute; for the well-conditioned athlete, 50-60 beats per minute; and for the extraordinary athlete, as few as 37 times per minute. The …

Transient Convective Heat Transfer Coefficient For Injection Into Rigid Vessel, James Edward Steiger

Theses and Dissertations

The purpose of this study was to develop and demonstrate a method for experimentally determining the convective heat transfer in a rigid vessel while air was being injected. The heat transfer took place between the air in the pressurized vessel and the surrounding walls which were maintained at a temperature of 32 F. with a circulating ice water bath. The study considers the effects of injection geometry and injection flow rate on the heat transfer process. The problem of heat transfer after injection has been considered by Means (1), and was responsible for establishing this study. The experimental technique used …

Conduction Error In Thermocouples Embedded In Low Conductivity Material, Tumkur G. Nagaraju

Theses and Dissertations

Thermocouples are generally used as devices to determine the internal temperature of any material. The purpose of the temperature measuring device is to measure the temperature which would exist at some known location if the device were not present. The thermocouples are embedded in the material in order to study the temperature-time history of the point of location. The presence of the thermocouple induces error in the temperature measured. This error becomes significant if heat is conducted into or away from the point of measurement by the sensor itself, or if the sensor insulates the point. This would result from …

A Theoretical And Experimental Study Of An Unsteady Pressure Measuring System, Ramesh R. Batki

Mechanical & Aerospace Engineering Theses & Dissertations

Experiments were performed to determine the frequency response of gas filled instrument tubes, and the results were correlated with a theoretical model. The theoretical model developed by Bergh and Tijdeman for a series connection of thin circular tubes and volumes was studied in full detail and employed. A measuring system was designed and built to measure pressure ratio and phase lag employing thin nylon or vinyl tubes and strain gage transducers. 1'leasurements were performed using cathode ray tube, strip chart, analog techniques and also a commercial electronic function analyzer and the various results were compared. The theoretical and experimental influence …

An Experimental Investigation Of The Vortex Sink Rate Sensors, Nelson L. Lu

Mechanical & Aerospace Engineering Theses & Dissertations

The vortex sink rate sensor device consists basically of an ideal sink flow between two coaxial disks. A sink tube was located at the center of one disk. The vortex was created by the rotation of the unit about its axis of symmetry. Five inch and 10 inch diameter of porous couplers were used for the air chamber here in this investigation. Several slenderness parameters, i.e., the ratio of the sink tube diameter to the height of the air chamber ^ro/n were conducted. Two probes were used to measure the static pressure and stagnation pressure respectively at various positions …

Transverse Vibration Of A Class Of Orthotropic Plates, Nicholas J. De Capua

Dissertations

This study determines the eigenvalues, eigenvectors, and nodal patterns of a class of orthotropic plates whose geometry is governed by the equation

(x/a)^α + (y/b)^β = 1,

where the parameters a, b, a, and a permit the plate geometry to vary over a range which includes the rhombus, circle, ellipse, square, and rectangle.

Variable thickness, inplane forces, and mixed or discontinuous boundary conditions are also considered. The following assumptions have been employed:

i). plate is thin with respect to other dimensions,

ii). deflections are small,

iii). rotary inertia and shear are neglected.

The method of analysis employed is …

A Theoretical And Experimental Study Of The Mechanism Of Axoplasmic Convection In Nerve Fibers Driven By Peristaltic Surface Waves, Robert John Biondi

Dissertations

In the study of cell biology, investigators have found that substances which are produced within the cell nucleus are sometimes found throughout the cell at points distant from the site of production. In the case of nerve cells (neurons), this is particularly dramatic because of the unusual elongated geometry of these cells.

A neuron possesses a cylindrical tubular extension called an "axon" or "axis cylinder" which is characterized by a large length-to-diameter ratio (10³-10⁶). The existence of a continuous proximo-distal flow of axoplasm within these cylindrical axons has now been demonstrated by numerous investigators. In …

Ole Miss Engineer 1971

Ole Miss Engineer

No abstract provided.

On The Phenomenon Of Vortex Street Breakdown, William W. Durgin, Sture K.F. Karlsson

Office of the Provost Scholarship

A von Kármán vortex street generated in the usual way was subjected to a deceleration, thereby changing the ratio of longitudinal to lateral spacing between the vortices. Distortion of the individual vortices followed which resulted in annihilation of concentrated vortex regions and creation of a stationary wake flow. This wake flow was itself dynamically unstable and developed into a new vortex street of a different frequency from the initial one. The breakdown of the initial vortex street is qualitatively explained by considering the convection of a concentrated vortex region due to the motion imposed by all the other vortices.

Ole Miss Engineer 1971

Ole Miss Engineer

No abstract provided.

Test 1088: Case 770 Manual Diesel 8-Speed (Chassis Sn 8675001 And Up), Nebraska Tractor Test Lab

Nebraska Tractor Tests

EXPLANATION OF TEST REPORT

GENERAL CONDITIONS

East tractor is a production model equipped for common usage. Power consuming accessories can be disconnected only when it is convenient for the operator to do so in practice. Additional weight can be added as ballast if the manufacturer regularly supplies it for sale. The static tire loads and the inflation pressures muse conform to recommendations in the Tire Standards published by the Society of Automotive Engineers.

PREPARATION FOR PERFORMANCE RUNS

The engine crank case is drained and refilled with a measured amount of new oil conforming to specifications in the operator’s manual. The …

Laminar Heat Transfer For Small Prandtl Number Fluids Including Step Change In Wall Temperature, Shiny Ting

Masters Theses

"The object of this investigation is to provide a simple means of determining the heat transfer from a flat plate which has an unheated leading length x₀. The case of steady, two-dimensional, laminar flow of an incompressible fluid with a Prandtl number of less than one is considered. Since there exists an unheated length and the Prandtl number of the fluid is less than one, the thermal boundary layer intersects the flow boundary layer. Thus, the solution of the problem divides into two regions. In this study, the problem is solved analytically by employing the energy integral equation. The temperature …

Faulty Germination Of Lupin Seeds, B J. Quinlivan

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

THE number of lupin seed samples tested in the seed laboratory over the last few years has shown a marked increase with the increasing popularity of lupins as a cash crop.

A seed with satisfactory germination is one which produces a healthy seedling. The germination of lupin samples tested in the laboratory has varied markedly.