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Test 1158: International Hydro 100 Diesel, 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 …

Test 1161: Minneapolis-Moline G955 Diesel, 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 …

Test 1168: Allis-Chalmers 7080 Diesel, 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 …

Test 1170: Steiger Couger Ii Diesel, 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 And Experimental Study Of The Dynamic Response Of A Press, Woosoon Bai

Doctoral Dissertations

"This dissertation presents a simplified mathematical model and computer simulation of the vertical motion of a press. The model is verified by comparing simulation results with actual field measurements.

Using this model, the computer simulation is then extended to study the dynamic response of a bolted press, one with loosened anchor bolts, and one which is isolated. Press performance, in terms of acceleration of the press, velocity of its foundation, and forces transmitted to the foundation, is analyzed in relation to the foundation mass and the stiffness of the isolators, where applicable. Comparative performances of the presses secured by the …

A Finite Element Method For Three-Dimensional Analysis Of Metal Forming, Nguyen Don Phu

Doctoral Dissertations

"The importance of metal forming by extrusion was reviewed. A Finite Element Approach was developed to analyze extrusion processes. A brick type linear element and the Upper Bound theorem were used to analyze the extrusion of a cylindrical billet into a square cross-section prism. A minimization technique for a non-linear functional with linear constraints was developed. Different types of boundary conditions were also formulated. A frictionless extrusion was simulated using the computer program developed. Velocity profiles at different sections of the deforming solid were obtained and an average extrusion pressure was predicted for a given area reduction ratio.

Extrusions from …

Direct And Inverse Heat Conduction In Rock Materials Using The Finite Element Method, Vernon Dale Allen

Doctoral Dissertations

"A finite element method is presented for solution of direct and inverse heat conduction problems in rock materials. Finite element programs for direct and inverse heat conduction problems were developed and demonstrated. Flow charts are given for the finite element programs.

The direct finite element heat conduction program changes material properties with temperature to approximate the temperature dependent properties of rock materials. An example problem was solved by the finite element method and also using Kirchoff's transformation. The finite element solution compared quite well with the Kirchoff transformation solution.

The inverse method utilizes the direct finite element heat conduction program …

Dropwise Condensation As Affected By Vapor Diffusion And Molecular Sticking, Salil K. Banerjee

Doctoral Dissertations

"Experimental values of heat flux in dropwise condensation on a gold plated vertical copper surface were determined in presence and absence of (or minute traces of) noncondensable gas. The noncondensable gas concentration varied from 0.0045% to 7.5% over a range of subcooling from 2.155 to 17.13°F and system pressure of 4.124 to 16.67 psia. The calculated heat transfer coefficient ranged from 1,545 to 11,135 Btu/hr-ft²-°F. In the part of the experiment where precautions were taken to avoid the presence of noncondensable gas in the water vapor, much higher values of heat flux were observed. Values of heat transfer coefficient ranging …

Measurements Of Condensation Coefficient Exhibited By Water Drops Grown On Rural Cloud Nuclei, Abbas M. Sinnarwalla

Doctoral Dissertations

"Values of condensation coefficient, ß, were experimentally determined for water drops grown on cloud nuclei in atmospheric air samples. The measured quantities were supersaturation, final drop size (6 to 7.5 µm radius), and time to grow from near dry radius to final radius. The drops were grown in a vertical-flow thermal diffusion chamber, at supersaturations near 0.5 and 1.0%. The final drop sizes were large enough so that ß did not depend upon the size of the nucleus producing a given drop. The average value of ß was 0.025 with a standard deviation of about 0.01"--Abstract, page 2.

A Study Of Some Heuristic Models For Predicting The Reflection From Spherical Surfaces., Bruce Wayne Rau

Masters Theses

"Four heuristic models' available for predicting the behavior or radiation Non regularly reflected from spherical surfaces have been studied. The four models include: the classical Lambert, the s-factor as deduced by Look, the Lommel-Seeliger, and the Euler's approach. Because each of these analyses was deduced for flat plate geometry, it was first necessary to integrate these flat plate expressions over the surface of a sphere to develop appropriate expressions for the power rejected from the surface of a sphere based upon e ach of the above theories. As an integral part of this investigation, various basic quantities were listed (i. …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

Numerical Modeling Of The Early Stage Of Cloud Formation In A Simulation Chamber, Adel Nassif Saad

Doctoral Dissertations

"A numerical model has been developed to simulate the growth of cloud droplets by condensation upon a spectrum of hygroscopic nuclei. The model is applicable to cloud simulation chamber conditions as well as to the study of the role of these nuclei on cloud base microstructure.

Equations are given for the growth by condensation of water vapor on a population of hygroscopic nuclei in a volume being cooled by expansion. The equations are integrated simultaneously, using Hamming's modified predictor-corrector method for given initial conditions, to obtain the droplet size distribution, temperature, pressure, supersaturation, and liquid water content. Temperature fluctuations, sedimentation …

Transient Thermal Stresses In A Sphere By Local Heating, J. B. Cheung, T. S. Chen, K. Thirumalai

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The problem of transient thermal stresses in a solid, elastic, homogeneous, and isotropic sphere is solved for uniform and nonuniform, local surface heating. The temperature solutions are obtained by using separation of variables and integral transformation. The corresponding thermal stresses are derived by superposing a particular displacement potential function on Boussinesq solutions. Numerical solutions for two particular cases of localized heating of a typical brittle spherical solid have been obtained and presented. The results indicate a tensile stress concentration in the interior of the solid below the heated zone. © 1974 by ASME.

Vibration Characteristics Of Free Thin Cylindrical Shells, Floyd M. Cunningham, D. E. Leanhardt

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper considers the flexural vibrations of free thin circular cylinders. A frequency equation is derived using free-free characteristic beam functions to represent the variation of mid-surface shell displacement components, u, v and w, with respect to the axial direction. Timoshenko strain-displacement relations for thin cylinders are used to determine elastic vibratory strain energy. Energy methods are applied to obtain the frequency equation and associated amplitude ratios for each of its roots. This energy solution is checked experimentally using a vibration exciter and numerically using the SABOR IV finite element program. With minor modification, the frequency equation conforms to the …

Analysis Of A High-Heat-Flux Water Heat Pipe Evaporator, Michael Einar Berger

Mechanical Engineering ETDs

An analysis was made to determine a surface which has potential use in a high-heat-flux, low-temperature-drop water heat pipe evaporator. A comprehensive survey of the literature was made to determine those surfaces which had high-heat-flux potential under evaporation. A circumferentially grooved surface was selected as the surface to be analyzed. Two groove geometries were selected for analysis, rectangular and triangular. A mathematical model of the grooves was constructed in order to predict the maximum surface heat flux capability. In addition, a model of the heat transfer within the fluted surface was proposed which postulated that conduction through the wall and …

Computer-Aided Design Of Light Aircraft To Meet Certain Aerodynamic And Structural Requirements, Joanne Lynn Walsh

Mechanical & Aerospace Engineering Theses & Dissertations

Nonlinear mathematical programming techniques are applied to a particular aircraft design problem, that of determining the maximum range design for light aircraft subject to certain aerodynamic and structural requirements. Search techniques available in an existing nonlinear optimization computer program, AESOP, are applied to the design problem. Seven design variables are used to define the wing dimensions, the wing skin thickness, the cruise velocity, the amount of fuel carried, and the engine horsepower. The influence of different design requirements on the range is observed and discussed.

Long-Term Retention Of Tritium In Man, Chin-Jen Ou

Electronic Theses and Dissertations

[No abstract provided.]

Measurement And Analysis Of Data In Turbulent And Transition Regions Of Two-Phase Flow, Akula Venkatram

Theses and Dissertations

The main aim of the project was to examine the possibility of using the hot wire anemometer to detect particles in a fluid. It was hoped that the presence of the particles would affect the autocorrelation plot and the energy spectrum of the velocities measured in the fluid.

Transient Convective Heat Transfer In Closed Containers During And After Gas Injection, Jennings Donell Means

Theses and Dissertations

This dissertation presents experimental data correlations for the spatially - averaged convective heat transfer coefficient for thin walled closed containers during and after gas injection. The different modes of heat transfer were identified, and correlations were made for each. Correlations are presented for the injection period, post-top injection, post-bottom injection, post- tangential, post-radial injection, and post-ejection heat transfer for various tank geometries. Of special significance are the very high heat transfer rates that were shown to be present in some cases immediately after injection. Heat transfer rates were shown to be, for a short period, up to almost two orders …

Analysis Of Heat Generation And Temperature In High Speed, High Temperature Bearing Balls, Hans R. Ringger

Theses and Dissertations

This thesis reports an investigation of the generation of heat on, and the prediction of temperature of high-speed, dry-film lubricated, stainless steel bearing balls.

The Design And Analysis Of An Electro-Pneumatic Signal Converter, Richard K. Thornton

Theses and Dissertations

In the field of process control it is desirable to study dynamic characteristics such as frequency response and distortion when determining just how equipment is to be controlled. Pneumatic controllers, transmitters, control valves, etc., all have dynamic behaviors which can be expressed mathematically as transfer functions. Each component plays an important role in determining the entire system behavior. Frequency response is one technique used in developing a component’s transfer function. By driving a device with a sinusoidal signal of fixed amplitude and frequency the output amplitude and phase shift are measured and compared with that of the input. Varying the …

An Aerodynamic Investigation Of The Causes Of Overhead Electrical Transmission Line Gallop, Eric Nathan Skousen

Theses and Dissertations

Overhead electrical transmission lines vibrate due to the action of a prevailing wind. These cable vibrations can be classified into two categories— high-frequency and low-frequency. The high-frequency vibrations, "aeolian" vibrations or "singing wires," is a low-amplitude phenomenon. It has been largely controlled with the use of various mechanical dampers [l, 2],