Engineering Commons^™

Robotic Arm Design For Compressor Handling, Eve Blair

Honors Capstone Projects and Theses

No abstract provided.

Ole Miss Engineer 1996

Ole Miss Engineer

No abstract provided.

Heat Transfer In Microchannels, Xianming Wang

Doctoral Dissertations

The objective of this research was to develop an analytical solution to the heat transfer problem in microchannels with slip-flow--a heat transfer problem for gases at low pressures or in extremely small geometries, and to verify this solution experimentally. In this investigation, an analytical expression for the velocity distribution with slip-flow was obtained which involved the Knudsen (Kn) number in an infinite series form. The result showed that the velocity always increased as the Knudsen number was increased. The Knudsen number for extremely small channels may become large enough to affect significantly the velocity distribution and consequently affect the heat …

The Crash Simulation And Analysis Of The Friendly Mobile Barrier, Bryan Edward Marz

Mechanical & Aerospace Engineering Theses & Dissertations

Mass transportation is an ever increasing alternative being researched and evaluated in today's society. With the increase of demand for such transportation, an increase in safety is also needed. This research entails the analysis of a new idea, The Friendly Mobile Barrier, in railroad crossing barrier design. The design is meant to prevent any approaching vehicle from crossing a railroad track and be survivable for those impacting the barrier.

Research conducted involves the crash simulation and analysis of the Friendly Mobile Barrier. The Friendly Mobile Barrier was analyzed structurally using finite element analysis. An advanced lumped-mass mathematical model software, Crash …

An Experimental Study Of An Advanced Polymeric Material For Use In Total Knee Replacements Including Gait Analysis Of Mobile Knee Bearings, Lisa Ann Scott

Mechanical & Aerospace Engineering Theses & Dissertations

The primary objectives of this research were to clinically examine the New Jersey Low Contact Stress (LCS)™ Rotating Platform and Meniscal knee bearing systems and to investigate the tribological properties of a new polymer for potential application in total joint replacement. Thus, clinical studies were performed on subjects having the LCSTM Rotating Platform knee bearing and subjects having the LCS™ meniscal knee bearing. The results indicated that there was a statistically significant difference in the braking force for both implant groups when compared to a control group. There was also a statistically significant difference noted for the LCS™ Rotating Platform …

Effects Of Initial Geometric Imperfections On The Behavior Of Graphite-Epoxy Cylinders Loaded In Compression, William Allen Waters Jr.

Mechanical & Aerospace Engineering Theses & Dissertations

The results of an experimental and analytical study of selected composite cylinders loaded in axial compression beyond buckling are presented. A comparison is made of buckling loads predicted by a nonlinear finite element code and those obtained from laboratory experiments. The initial geometric imperfections for each specimen were defined mathematically for inclusion in the finite element model. The experimental effort consisted of testing five graphite-epoxy cylindrical specimens. Four of the specimens were 16 plies thick; one of these had quasi-isotropic wall properties, another consisted entirely of angle plies, while the remaining specimens of this wall thickness were of two different …

The Effectiveness Of Film Cooling In A Hypersonic Flowfield With Favorable Pressure Gradients, Julie A. Young

Mechanical & Aerospace Engineering Theses & Dissertations

The impetus of this technical document is to report results of aerothermodynamic cooling of a scramjet nozzle under favorable pressure gradients. The goals of film cooling are to protect the nozzle skin from the high enthalpy combustor flow, reduce regenerative cooling requirements, and decrease nozzle skin friction. A hypersonic nozzle configuration for which experimental data exists was selected as the basis of this numerical study. As a first step, the numerical results of film cooling along a flat plate are compared to previous literature to validate the numerical model. Subsequently, computations are performed to study the effects of varying the …

Parametric Correlations For Generic Scramjet Combustors With Ramp-Type Injectors, Jason Granville Bush

Mechanical & Aerospace Engineering Theses & Dissertations

Development of an efficient scramjet combustor requires the use of computational models due to the cost of full-scale physical testing in the speed regime of Mach 10 through Mach 18. This study focuses upon the database generated by one such computational model, SHIP3D, which describes a generic scramjet combustor using ramp-type file! injectors. Three generalized parametric equations have been developed from this database, which describe the fuel-air mixing efficiency within the scramjet combustor as a function of normalized-axial combustor distance, ramp injector-region lift coefficient, and stoichiometry. It is shown that one of the three equations nearly models the trends as …

A Fluid Flow Analysis Of Aluminum 356.0 In The Vacuum Assisted Countergravity Method, John Launstein

Graduate Research Papers

The purpose of this study is to determine the fluid flow pattern obtained through the use of the countergravitaional process. The physical fluid flow model assists design engineers in their casting design of parts utilizing the LS-Vac technology thereby reducing tooling costs and time losses.

Microwave Telemetry For Sensing Conditions In Enclosed Rotating And/Or Reciprocating Machinery, Richard L. Campbell, Douglas B. Brumm, Carl L. Anderson, Glen L. Barna

Michigan Tech Patents

An apparatus for measuring the pressure within the torque converter of an automatic transmission. The apparatus includes a sensor to sense the interior pressure of the torque converter and generate an electrical signal representative of that pressure. That signal is converted to microwave energy which is radiated into the interior of the torque converter housing from a microwave transmitter located within the torque converter. Receiving microwave antennae exposed to the housing interior receive the microwaves and transmit an electrical signal corresponding to the microwave energy to a remote readout external of the torque converter. The receiving antenna are preferably in …

History Of Applying Photovoltaics To Disaster Relief, Florida Solar Energy Center, William Young

FSEC Energy Research Center®

Hurricanes, floods, tornadoes, earthquakes, and other disasters can happen any place, any time. Major disasters destroy homes and businesses, and leave many people without adequate medical services, portable water, electrical service and communications. In response to the need for electrical service, solar energy offers a source of quite, safe, pollution-free power. Over the last few years, photovoltaic (solar electricity) power systems have provided energy for various disaster all over the country. Photovoltaics (PV) have been used to power vaccine refrigerators, medical equipment, lighting, radios, fans, communications, traffic devices and other electrical equipment. Previously, photovoltaics have supplied emergency power for Hurricane …

Chemcial Vapor Deposition Precursor Chemistry. 5. The Photolytic Laser Deposition Of Aluminum Thin Films By Chemical Vapor Deposition, John A. Glass, Seong-Don Hwang, Saswati Datta, Brian W. Robertson, James T. Spencer

Department of Mechanical and Materials Engineering: Faculty Publications

Thin films of very high purity aluminum were formed from the laser photolysis of trimethylamine alane (TMAA) using both ultraviolet (pulsed nitrogen) and visible (argon ion) laser irradiation on a variety of substrates including gold. Si (111), GaAs (110) and Teflon (PTFE). At thicknesses of up to 1 μm, nearly linear growth rates of 377 Ås^-1 and 112 Ås^-1 were observed. The formation of volatile species formed during the deposition of aluminum from TMAA was investigated by quadrupole mass spectrometry (QMS) of the reactant gas stream. The highest intensity post-deposition mass fragments were observed at m/z 58, …

Numerical Analysis Of Two And Three Dimensional Recessed Flame Holders For Scramjet Applications, Douglas L. Davis

Theses and Dissertations

This study investigated the flame holding properties of recessed cavities in supersonic flow using numerical analysis techniques. A simplified analytical model indicated that an important property for flame holding was the lower residence time. Several chemical kinetic rate models for hydrogen and hydrocarbon combustion were compared. The perfectly stirred reactor model also indicated that trace species diffusion should increase flame spreading rate, and that heat loss reduces flame holding limits. After nonreacting calibration, two-dimensional simulations confirmed the perfectly stirred reactor results for blowout limits. Also, the effect of trace species diffusion on flame spreading was shown to be negligible, and …

Bounding Elastic Constants Of An Orthotropic Polycrystal Using Measurements Of The Microstructure, Brent L. Adams, M. J. Beran, T. A. Mason, Ted Olsen

Faculty Publications

We show how information about the elastic stiffness and compliance of an orthotropic polycrystal may be obtained from measurements of the statistical properties of the microstructure. We begin by discussing the statistical properties of the governing equations and the hierarchy that results when the equations are averaged. Perturbation solutions are obtained in terms of low-order statistical information. Using methods previously developed, we derive bounds for the elastic stiffnesses and compliances. A heirarchy of bounds is derived using the statistical information obtained from measurements of the microstructure. We discuss the methods used to obtain the correlation functions of the microstructure and …

How Contractors Really Size Air Conditioning Systems, Florida Solar Energy Center, Robin Vieira

FSEC Energy Research Center®

This paper presents results from 489 of the 5559 Florida air conditioning contractors surveyed (an 8.5% response rate) regarding equipment sizing methods in new residences. Air conditioning sizing is accomplished by using ACCA's Manual-J procedure by 33% of the respondents, software by 34.4% of the respondents, square-footage by 24.2% and other estimate procedures by about 8.4%. Those using square-footage estimates varied from 350 square-feet- per-ton to 700 square-feet-per-ton. Over a third of respondents indicated oversizing intentionally on some jobs, in order to avoid complaints, accommodate future expansions, enable quicker cooling down of homes, and to allow for lower cooling set …

Are Energy Savings Due To Ceiling Fans Just Hot Air?, Florida Solar Energy Center, Patrick James

FSEC Energy Research Center®

Human comfort studies have shown that people prefer higher temperatures when they are subjected to a breeze. Ceiling fans are often used to create air motion in residences. Simulation studies (including one given in this paper) have demonstrated that in Florida, using ceiling fans combined with raising a home's temperature 2° F will generate about a 14% net savings in annual cooling energy use (subtracting out the ceiling fan energy and accounting for internally released heat). This savings drops to 2.6% with a 1° F increase in set point and to a negative 3.7% savings with only a 0.5° F …

Recent Developments In Extrusion Freeform Fabrication (Eff) Utilizing Non-Aqueous Gel Casting Formulations, Greg Hilmas, John L. Lombardi, Robert A. Hoffman, Kevin Stuffle

Materials Science and Engineering Faculty Research & Creative Works

Extrusion Freeform Fabrication (EFF) was shown to be an extremely versatile method for fabricating Functionally Graded Materials (FGMs) The approach is inexpensive and potentially feasible for grading between any thermodynamically compatible ceramic-metal, ceramic-ceramic, or metal-metal material combination. Several material systems were investigated in this study including alumina-304 stainless steel, zirconia-304 stainless steel, alumina-Inconel 625, zirconiaInconel625, alumina-nickel aluminide, zirconia-nickel aluminide, titanium carbide-InconeI625, titanium diboride-nickel aluminide, and tungsten carbide-nickel aluminide. A controlled gradient was demonstrated between the end members for all of the above compositions. The FGMs were hot pressed to achieve near theoretical densities, providing flexural strengths as high as 1000 …

Proposal For Renovation Of 1920 Tractor Test Lab Into Museum, Tractor Museum

Lester F. Larsen Tractor Museum: Planning and Development Documents

Bids for Renovating Roof State Fair Display Further Funding for Renovation

Daylight Dimming Systems: Studies In Energy Savings And Efficiency, Florida Solar Energy Center, Lynn Schrum

FSEC Energy Research Center®

Three studies were conducted at Florida Solar Energy Center (FSEC) to study the lighting energy savings of daylight dimming systems. The Daylighting Test Facility (DTF) was used to study daylight dimming systems and how aperture orientation and blinds affect performance. The energy consumption was compared in two pairs of offices for all four window orientations: north, south, east and west. One office in each pair had blinds in a fixed position (down and open) and the other office had no blinds. The study showed that the energy savings ranged from 24% to 51% depending on the orientation and blinds.

The …

Measured Field Performance And Energy Savings Of Occupancy Sensors: Three Case Studies, Florida Solar Energy Center, David Floyd

FSEC Energy Research Center®

Occupancy sensors have the potential to significantly reduce energy use by switching off electrical loads when a normally occupied area is vacated. While occupancy sensors can be used to control a variety of load types, their most popular use has been to control lighting in commercial buildings. Manufacturers claim savings of 15% to 85%, although there is little published research to support the magnitude or timing of reductions. Energy savings and performance are directly related to the total wattage of the load being controlled, effectiveness of the previous control method, occupancy patterns within the space and proper sensor commissioning. In …

Finite Element Study Of The Effect Of The Blank Holder Force And Drawbead On The Sheet Metal's Drawability In The Deep Drawing Process, Shada Philip Halim

Archived Theses and Dissertations

No abstract provided.

The Development And Evaluation Of The Knife Finite Element, Brett W. Clark

Theses and Dissertations

This thesis presents the development and evaluation of the knife finite element which is a degenerate case of a hexahedral element. The knife connectivity is an artifact of automatic all-hexahedral mesh generators. Currently, knives are propagated to the surface of the mesh for removal. However since this disturbs the surface mesh, other alternatives are needed. This thesis investigates the option of leaving the knife connectivity in the mesh and treating it as a valid finite element. The shape functions and stiffness matrix for the knife element are derived and evaluated using theoretical and practical evaluations. It is concluded that the …

Solute Nucleation And Growth In Supercritical Fluid Mixtures, Gregory T. Smedley, Gerald Wilemski, W. Terry Rawlins, David B. Oakes, Prakash Joshi, William W. Durgin

Office of the Provost Scholarship

This research effort is directed toward two primary scientific objectives: (1) to determine the gravitational effect on the measurement of nucleation and growth rates near a critical point and (2) to investigate the nucleation process in supercritical fluids to aid in the evaluation and development of existing theoretical models and practical applications. A nucleation pulse method will be employed for this investigation using a rapid expansion to a supersaturated state that is maintained for ≈ 1 ms followed by a rapid recompression to a less supersaturated state that effectively terminates nucleation while permitting growth to continue. Nucleation, which occurs during …

Characterization Of The Si/Sio2 Interface Formed By Remote Plasma Enhanced Chemical Vapor Deposition From Sih4/N2O With Or Without Chlorine Addition, Young-Bae Park, Xiaodong Li, Shi-Woo Rhee

Faculty Publications

The Si/SiO₂interface formed by remote plasma enhanced chemical vapor deposition (RPECVD) at low temperature with SiH₄/N₂O or SiH₄/N₂O/Cl₂ was studied and compared with thermal oxidation. The interface of the CVD SiO₂ without chlorine addition is rougher than that with chlorine addition. But the surface roughness of CVD SiO₂ films increases with chlorine addition. The thermal oxidation induces strong interface strains, and the strains generated by the CVD SiO₂ without chlorine addition are stronger and are distributed more nonuniformly than those by the chlorinated SiO₂. …

Numerical Prediction Of Turbulent Diffusion Flames Formed By Cylindrical Tube Injector, Ali S. Kheireddine

Mechanical & Aerospace Engineering Theses & Dissertations

This work summarizes numerical results for a diffusion flame formed from a cylindrical tube fuel injector, issuing gaseous fuel jet vertically in a quiescent atmosphere. Both pure fuels as well as fuel mixtures are examined. The primary objective is to predict the flame base height as a function of the jet velocity. A finite volume scheme is used to discretize the time-averaged Navier-Stokes equations for the reacting flow, resulting from the turbulent fuel jet motion. The turbulent stresses, and heat and mass fluxes are computed from the Reynolds stress turbulence model. A chemical kinetics model involving a two-step chemical reaction …

A Progressive Damage Methodology For Residual Strength Predictions Of Center-Crack Tension Composite Panels, Timothy William Coats

Mechanical & Aerospace Engineering Theses & Dissertations

An investigation of translaminate fracture and a progressive damage methodology was conducted to evaluate and develop residual strength prediction capability for laminated composites with through penetration notches. This is relevant to the damage tolerance of an aircraft fuselage that might suffer an in-flight accident such as an uncontained engine failure. An experimental characterization of several composite materials systems revealed an R-curve type of behavior. Fractographic examinations led to the postulate that this crack growth resistance could be due to fiber bridging, defined here as fractured fibers of one ply bridged by intact fibers of an adjacent ply.

The progressive damage …

Rectified Synthesis Of Coupler Driven Four Bar Mechanisms For Two And Three Position Motion Generation, Ramanujam Thiruvenkatachari

Mechanical & Aerospace Engineering Theses & Dissertations

Four-bar mechanisms are widely used in the industry to solve a variety of motion problems. Till recently, their design was based on fundamental kinematics and brute force techniques, resulting in impractical designs and spurious linkages that failed to perform their desired functions effectively.

Procedures have been developed and implemented to guide the rigid body of crank driven four-bar linkages, through a set of design positions with techniques to avoid their defects. However, the practical applications of linkages used in the industry are coupler driven, with primitive synthesis procedures based on trial and error. The opening and closing of the hood …

Lattice Truss Structural Response Using Energy Methods, Winfred Scottson Kenner

Mechanical & Aerospace Engineering Theses & Dissertations

A deterministic methodology is presented for developing closed-form deflection equations for two-dimensional and three-dimensional lattice structures. Four types of lattice structures are studied: beams, plates, shells and soft lattices. Castigliano's second theorem, which entails the total strain energy of a structure, is utilized to generate highly accurate results. Derived deflection equations provide new insight into the bending and shear behavior of the four types of lattices, in contrast to classic solutions of similar structures. Lattice derivations utilizing kinetic energy are also presented, and used to examine the free vibration response of simple lattice structures. Derivations utilizing finite element theory for …

Energy Use Analysis Of A Multi-Unit Housing Facility A Parametric Study, Brian David Cooper

Mechanical & Aerospace Engineering Theses & Dissertations

In the continuing effort to reduce the energy use of buildings, design engineers and architects are called upon to design facilities which are more efficient and use less energy. The prediction of the energy used by a building's systems and occupants, for different design options and combinations, is an important part of the design of an energy efficient building.

An energy use analysis was conducted to determine the accuracy of a computerized building energy analysis simulation when only preliminary design information is available. Additional studies were made to determine the accuracy of the simulation as more detailed design, construction and …

An Investigation Of The Influence Of Tightening Torque And Sea Water On Pultruded Gfrp Composite Bolted Joints, Satish Devara

Mechanical & Aerospace Engineering Theses & Dissertations

Pultruded glass fiber-reinforced polymeric matrix composites are candidate materials for ever-increasing structural applications due to their continuous production capability, light weight and excellent properties. In this investigation an extensive experimental study has been carried out to understand their structure, basic mechanical properties, and influence of fiber orientation on the unnotched, notched and pin-loaded tensile strength. Furthermore, the effects of sea water and tightening torque separately and together on the failure loads and failure modes of the bolted joints are also studied. It is shown that blockshear failure mode is also a principal mode of failure in the bolted joints of …