Engineering Commons^™

Innovations In Heat Pumps, Ronald Hunter Howell, Harry J. Sauer Jr.

UMR-MEC Conference on Energy / UMR-DNR Conference on Energy

The status of the residential heat pump industry is reviewed. Some potential improvements in energy efficiency, operational reliability, and initial cost are described and delineated. These possible innovations include two-speed or variable speed compressors, reliable defrost initiation and termination, improved system components, modifications to the basic thermodynamic cycle, add-on-heat pumps, solar assisted heat pumps, annual cycle energy system, chemical heat pumps, and gas fired heat pumps.

Sizing Of Air-Conditioning Systems -- The New Methodology, Harry J. Sauer Jr., Ronald Hunter Howell

UMR-MEC Conference on Energy / UMR-DNR Conference on Energy

Accurate cooling load calculations for sizing air-conditioning equipment are more important today than ever. Properly sized equipment saves energy. This paper briefly describes a new method developed by ASHRAE for such calculations .

Design And Operational Characteristics Of A Retrofit Solar Heating System, D. J. Wetteroff, Bassem F. Armaly

UMR-MEC Conference on Energy / UMR-DNR Conference on Energy

The construction and the operation of a retrofit solar assisted space heating system are described. Performance characteristics of each component were measured and used to estimate the contribution of solar energy to the yearly space heating energy requirements.

University Of Missouri--Rolla Wood Energy Research, Yildirim Omurtag, V. J. Flanigan, Nathan E. Welch

UMR-MEC Conference on Energy / UMR-DNR Conference on Energy

The overall objective of this project is to conduct a research and development program which will lead to the early commercialization of wood gasification technology to process wood residues typical of those found in the Ozark region.

Ole Miss Engineer 1978

Ole Miss Engineer

No abstract provided.

Effect Of Precursor Heating On Radiating And Chemically Reacting Viscous Flow Around A Jovian Entry Body, Kuo Yen Szema

Mechanical & Aerospace Engineering Theses & Dissertations

The influence of changes in the precursor region flow properties (resulting from absorption of the radiation from the shock layer) on the entire shock layer flow phenomena around a Jovian entry body is investigated under physically realistic conditions. In the precursor region, the flow is considered to be inviscid and the variations in flow properties are determined by employing the small perturbation technique as well as the thin layer approximation. The flow in the shock layer is assumed to be steady, axisymmetric and viscous. The analysis is carried out by considering both the chemical equilibrium and nonequilibrium composition of the …

The Design And Analysis Of A Unique Broadband Underwater Acoustic Source, Allan Mark Young

Retrospective Theses and Dissertations

Requirements exist for a unique type of underwater acoustic source. The transducer is in the form of a linear array of discrete elements and is required to have a constants transmitting voltage response and carefully controlled directivity characteristics over a two octave bandwidth. A generalized model of a linear array of cylindrical piezoelectric ceramic acoustic radiators is developed and applied to the design of a prototype which operates over approximately one half of the required bandwidth. The prototype transducer was built and the measured results are compared with those predicted by the model. Recommendations are made for improving the performance …

Interaction Between Structures And Fluids, Rahim Falsafi-Haghighi

Dissertations

A finite element model for the study of solid-fluid interaction, with applications in flow-induced vibration analysis of reactor vessel and heat exchanger internals, is presented. The model is based on the discretization of the solid equation of motion and the fluid continuity and momentum equations and employs the solid displacements together with the fluid pressure and velocity components as the nodal degrees of freedom. This permits a realistic and accurate implementation of boundary conditions, in contrast with methods using solid displacements and fluid pressure as the only field variables. The numerical solution of the resulting matrix equation, involving non-symetric matrices, …

An Analytical Comparison And Contrast Of The Automobile Rotary Combustion Engine And The Reciprocating Engine, Eric K. Earle

Graduate Research Papers

The ReCE, although possessing many good characteristics as a motive source of power, is still somewhat far from achieving the desired efficiency in man's quest for better economical and practical means of transportation, due to the lack of higher speeds and its inability to burn all of the fuel admitted as a result of its large number of moving parts, their weight, size and reciprocating motion.

The design and development of the RCE has overcome many of the above problems inherent in the ReCE, and, therefore, has the potential of replacing the ReCE as the major source of automotive power …

Surface Roughness Effects In Hydrodynamic Lubrication, Johnny Lynn Teale

Mechanical Engineering ETDs

Prediction of pressure and leakage in a hydrodynamic bearing when surface roughness effects are important is an essential step in bearing design. The inclusion of surface roughness effects in bearing analysis allows more accurate prediction of bearing life. It has been shown that the average flow model developed by Cheng and Patir is a promising technique for determining surface roughness effects. The objective of this investigation is to examine the validity, applicability and limitation of the average flow model. Validity of the average flow model is ascertained by checking the independence of flow factors. Discussion of the general Reynolds equation …

Inviscid Two-Dimensional Vortex-Panel Method For Calculating The Pressure Distribution Over Noncircular Cylinders At Various Flow Incidence Angles, Sophia Kokkinos Ashley

Mechanical & Aerospace Engineering Theses & Dissertations

A method. has been implemented to calculate the potential flow pressure distribution over noncircular cylinders at various flow incidence angles. The inviscid, solution has been obtained by replacing the surface of a noncircular cylinder with a vortex sheet. The surface has been approximated by a number of flat panels. Each vortex panel has been assumed to have a constant vorticity, and the condition of no-circulation applied.. Solutions yield the local tangential velocity and pressure coefficient at each point.

The accuracy of the method has 'been established through comparison of the predicted results with existing exact theoretical results.

Comparisons of the …

Design, Calibration, And Application Of A Sensor For Measuring Time Dependent Angle Of Attack Of Helicopter Blades, Weiyuan Henry Liu

Mechanical & Aerospace Engineering Theses & Dissertations

Various pressure probes were designed and tested which could be attached to helicopter blades when a helicopter is in flight. The pressure probes consisted of spherical heads which were held in place by cylindrical shanks. Built inside the heads were transducers to measure the pressure differential between pressure ports which were located on the front portion of the spherical head facing the airstream. Data was obtained over a range of airstream velocity of 11,6 to 88.4- m/s (38 to 290 ft/sec), corresponding to Reynolds numbers of 0.24 to 1.84x10⁵ based on the sphere diameter. Both static and dynamic tests …

Numerical Control Machining, Dennis L. Maclennan

Graduate Research Papers

Accurate and timely data depicting major aspects of manufacturing are essential to allow management to exercise effective controls for investments relating to automated equipment. One specific area of automated equipment can be termed "numerical control" (N/C) . "N/C is a technique for the control of production tools by information prerecorded in symbolic form (Devries, 1971, p. 1)." l This study is concerned with gathering material on the functional use and operation of N/C equipment. Specifically, the following areas of study were:

(1) to gather historical information on N/C equipment development;

(2) to investigate who are the major manufacturers of N/C …

Dynamics Of Submerged Cylindrical Shells With Eccentric Stiffening, Kerry Kier-Ten Chu

Dissertations

A theoretical analysis is presented for treating the free vibrations of submerged, ring stiffened cylindrical shells with simply supported ends. The effects of the eccentric stiffeners are averaged over the thin-walled isotropic cylindrical shell. The energy method is utilized and the frequency equation is derived by Hamilton's Principle. All three degrees of freedom are considered. Numerical results are presented for frequencies and mode separation for several cases of interest. Comparisons with previous theoretical and experimental results indicate good agreement. The cylindrical wave approximation and the plane wave approximation for the field equation were investigated. Their applicability was evaluated and the …

Deposition Of Suspensions In Laminar Flow In The Entrance Region Of Channels With Diffusive, Electrostatic And Gravitational Effects, Thomas Anthony Korjack

Dissertations

This investigation entailed the consideration of the deposition of suspensions in laminar flow in the entrance region of a parallel-plate channel, and both converging and diverging channels, under the combined influences of diffusive, electrostatic and gravitational effects. The fluid phase was assumed to be incompressible, steady and laminar; the particle phase was assumed to be steady, laminar, dilute, and with negligible lift force.

The complete solution of the problem involved solving the boundary layer equations for the completely viscous fluid phase, and the particulate momentum, continuity and potential equations for the particle phase. Since the resulting equations are non-linear partial …

Test 1276: White Field Boss 2-155 Dsl 18-Speed, Nebraska Tractor Test Lab

Nebraska Tractor Tests

EXPLANATION OF THE TEST PROCEDURE General Tractors are tested at the University of Nebraska according to the Agricultural Tractor Test Code approved by the American Society of Agricultural Engineers and the Society of Automotive Engineers or official Nebraska test procedure. The manufacturer selects the tractor to be tested and certifies that it is a stock model. Each tractor is equipped with the common power consuming accessories such as power steering, power lift pump, generator, etc., if available. Power consuming accessories may be disconnected only when the means for disconnecting can be reached from the operating station. An official representative of …

Test 1275: White Field Boss 2-135 Diesel 18-Speed, Nebraska Tractor Test Lab

Nebraska Tractor Tests

EXPLANATION OF THE TEST PROCEDURE General Tractors are tested at the University of Nebraska according to the Agricultural Tractor Test Code approved by the American Society of Agricultural Engineers and the Society of Automotive Engineers or official Nebraska test procedure. The manufacturer selects the tractor to be tested and certifies that it is a stock model. Each tractor is equipped with the common power consuming accessories such as power steering, power lift pump, generator, etc., if available. Power consuming accessories may be disconnected only when the means for disconnecting can be reached from the operating station. An official representative of …

A Design Study For A Wavy Hydrodynamic Mechanical Face Seal, Raymond Edward Pierce

Mechanical Engineering ETDs

A desirable objective of mechanical face seal design is to achieve the maximum hydrodynamic load support possible while main­taining an acceptable leakage. In this way, mechanical face seal life can be greatly extended as the wear of the seal faces is significantly reduced. It has been shown that circumferentially varying waviness of one of the faces of a mechanical face seal causes such hydrodynamic lubrication.

The objective of this investigation is to examine the performance characteristics of the wavy mechanical face seal by studying the effects of certain design parameters. Seal performance is measured by leakage and wear rate. The …

Geothermal Energy: Heat Extraction From Hot-Dry-Rock Masses In The Presence Of Secondary Thermal Cracks, Yaw-Min Lu

Mechanical Engineering ETDs

Additional heat extraction from geothermal energy reservoirs depends on the feasibility to extend the main, hydraulic fracture through secondary thermal cracks of the adjacent hot rock. When the main, hydraulic fracture is cooled sufficiently, these secon­dary thermal cracks are produced normal to the main fracture surface, As such, both the heat transfer surface area and heat energy available to the fluid circulating through the main, hydraulic fracture system increase.

Axisymmetric Air Jet Impinging On A Hemispherical Concave Plate, Stefan Jachna

Dissertations

This experimental study was conducted on an axisymmetric air jet impinging normally on a smooth, hemispherical, concave plate. The jet Reynolds numbers, based on bulk nozzle velocity and nozzle exit air properties, were between 14,000 and 75,000.

The impingement plate used in this work was a hemispherical surface with the radius of 94 mm.

Calibrated Pitot tubes and a micromanometer were used for pressure and velocity measurements. The Pitot tubes were mounted on precision positioning mechanisms permitting the accurate traversing of any direction in space. The test air flow rate was measured with calibrated rotometers.

The following results of this …

Ole Miss Engineer 1978

Ole Miss Engineer

No abstract provided.

Analysis Of Moisture Absorption And Diffusion In Fiber Reinforced Polymeric Resin-Matrix Composite Materials, Stephen Stern Tompkins

Mechanical & Aerospace Engineering Theses & Dissertations

The diffusion of moisture through fiber reinforced polymeric-matrix composite materials has been studied analytically. The diffusion in the orthotropic, nonhomogeneous material was modeled, in detail, with a two-dimensional transient diffusion analysis. An effective diffusivity for the composite was determined in terms of the fiber volume fraction and the resin diffusivity. This effective diffusivity is in better agreement with recent data than those previously determined using less complex models.

The influence of both material and environmental parameters on the moisture content of the composite was determined analytically. Predicted moisture contents were compared over a wide range of values for emittance, solar …

Test 1270: Allis-Chalmers 5020 Dsl, Nebraska Tractor Test Lab

Nebraska Tractor Tests

EXPLANATION OF THE TEST PROCEDURE General Tractors are tested at the University of Nebraska according to the Agricultural Tractor Test Code approved by the American Society of Agricultural Engineers and the Society of Automotive Engineers or official Nebraska test procedure. The manufacturer selects the tractor to be tested and certifies that it is a stock model. Each tractor is equipped with the common power consuming accessories such as power steering, power lift pump, generator, etc., if available. Power consuming accessories may be disconnected only when the means for disconnecting can be reached from the operating station. An official representative of …

Test 1286: Kubota L185 Dt Diesel, Nebraska Tractor Test Lab

Nebraska Tractor Tests

EXPLANATION OF THE TEST PROCEDURE General Tractors are tested at the University of Nebraska according to the Agricultural Tractor Test Code approved by the American Society of Agricultural Engineers and the Society of Automotive Engineers or official Nebraska test procedure. The manufacturer selects the tractor to be tested and certifies that it is a stock model. Each tractor is equipped with the common power consuming accessories such as power steering, power lift pump, generator, etc., if available. Power consuming accessories may be disconnected only when the means for disconnecting can be reached from the operating station. An official representative of …

Test 1295: Case 2090 Powershift Diesel, Nebraska Tractor Test Lab

Nebraska Tractor Tests

EXPLANATION OF THE TEST PROCEDURE General Tractors are tested at the University of Nebraska according to the Agricultural Tractor Test Code approved by the American Society of Agricultural Engineers and the Society of Automotive Engineers or official Nebraska test procedure. The manufacturer selects the tractor to be tested and certifies that it is a stock model. Each tractor is equipped with the common power consuming accessories such as power steering, power lift pump, generator, etc., if available. Power consuming accessories may be disconnected only when the means for disconnecting can be reached from the operating station. An official representative of …

Test 1268: Same Tiger 100 Dsl, Nebraska Tractor Test Lab

Nebraska Tractor Tests

EXPLANATION OF THE TEST PROCEDURE General Tractors are tested at the University of Nebraska according to the Agricultural Tractor Test Code approved by the American Society of Agricultural Engineers and the Society of Automotive Engineers or official Nebraska test procedure. The manufacturer selects the tractor to be tested and certifies that it is a stock model. Each tractor is equipped with the common power consuming accessories such as power steering, power lift pump, generator, etc., if available. Power consuming accessories may be disconnected only when the means for disconnecting can be reached from the operating station. An official representative of …

Test 1282: Steiger Tiger Iii St-450 And St-470 6-Speed (Diesel), Nebraska Tractor Test Lab

Nebraska Tractor Tests

EXPLANATION OF THE TEST PROCEDURE General Tractors are tested at the University of Nebraska according to the Agricultural Tractor Test Code approved by the American Society of Agricultural Engineers and the Society of Automotive Engineers or official Nebraska test procedure. The manufacturer selects the tractor to be tested and certifies that it is a stock model. Each tractor is equipped with the common power consuming accessories such as power steering, power lift pump, generator, etc., if available. Power consuming accessories may be disconnected only when the means for disconnecting can be reached from the operating station. An official representative of …

Thrust-Impact Rock-Splitter, George Bromley Clark, T. F. Lehnhoff

Mining Engineering Faculty Research & Creative Works

A rock splitting tool having elongate laterally expanding metal pressure bars or feathers and an axial sliding wedge or spreader for radially separating the feathers, the wedge being driven by the combined and superimposed forces of a hydraulic thrust servomotor and an impact hammer. The driving paths for transmitting forces to the wedge are coaxial and partially in series and partially in parallel.

Two-Step Photoionization Of Potassium Atoms, Kaare J. Nygaard, Robert J. Corbin, James A. Jones

Physics Faculty Research & Creative Works

The cross section for photoionization of potassium atoms in the 4P2 states has been measured in a triple-crossed-beam experiment. © 1978 The American Physical Society.

Comparison Of Theoretical And Experimental Results Pertaining To R-Curves In Low And High Ductility Solids, Rabindra Nath Dash

Electronic Theses and Dissertations

Existing linear elastic fracture mechanics and J-integral analyses are well suited for safety assessments of high-strength, low-toughness materials. These analyses apply only to the onset of crack growth, which is usually tantamount to crack instability and structural failure in that class of materials. However, this is not the case for the low-strength, high-toughness materials in which crack instability may be preceeded [sic] by extensive stable crack growth under rising loads. Here, a substantial margin of safety may exist even when the onset of crack growth is imminent. This thesis describes research leading to a ductile fracture-mechanics methodology designed to treat …