Mechanical Engineering Commons^™

University Of Missouri-Rolla Cloud Simulation Facility: Proto Ii Chamber, Daniel R. White, James L. Kassner, John C. Carstens, Donald E. Hagen, John L. Schmitt, Darryl J. Alofs, Alfred R. Hopkins, Max B. Trueblood, Max W. Alcorn, William L. Walker

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The Graduate Center for Cloud Physics Research at UMR Has Developed a Cloud Simulation Facility to Study Phenomena Occurring in Terrestrial Clouds and Fogs. the Facility Consists of a Pair of Precision Cooled-Wall Expansion Chambers Along with Extensive Supporting Equipment. the Smaller of These Chambers, Described in This Article, is Fully Operational, and is Capable of Simulating a Broad Range of In-Cloud Thermodynamic Conditions. It is Currently Being Used to Study Water Drop Growth and Evaporation for Drops Nucleated (Activated) on Well-Characterized Aerosol Particles. Measurements Have Been Made Not Only for Continuous Expansions (Simulated Updraft) But Also for Cyclic Conditions, …

Definition Of An Asymmetric Domain For Intercrystalline Misorientation In Cubic Materials In The Space Of Euler Angles, Brent L. Adams, Junwu Zhao

Faculty Publications

The authors wish to acknowledge the support of the United States Department of Energy, Office of Basic Energy Sciences, under grant No. DE-FG02-85ER45203. Critical review by Professor Dorian Hatch of the Physics Department at Brigham Young University is gratefully acknowledged. A new asymmetric domain for intercrystalline misorientation is defined in the space of Euler angles for materials exhibiting cubic (Oh point-group) lattice symmetry. The invariant measure for this new domain is nearly constant; this is in significant contrast to the previous domain defined by MacKenzie [Biornetrika (1958), 45, 229-240]. Distribution functions in the misorientation can now be represented with greater …

Theoretical Thermodynamic Properties Of Low Temperature Fluids, Zul Azhar Zahid Jamal

Masters Theses

The thermodynamic functions for low temperature fluids are computed using parametric integral equations and perturbation theory. Parametric integral equation N is applied to a low temperature Lennard-Jones gas. It is found that there is no significant improvement over the better known parametric integral equation C. The two parameter integral equation T is applied to a low temperature square-well potential and is found to be unsatisfactory at reduced temperatures of T*= 1.4 and 1.6, but quite accurate at T* = 2.2. The equation T results for T* = 2.2 are used as the reference system in perturbation theory computations. Tables of …

Investigation Of The Excessive Bending Stiffness Of The Four Node Plane Stress/Plane Strain Quadrilateral Finite Element, William Lee Hacker

Mechanical Engineering ETDs

An eigenvalue-eigenvector approach is taken to study the details of the causes of and remedies for the overly stiff behavior exhibited by this element. The exact functional variation of the eigenpairs with element aspect ratio and material properties are derived for rectangular elements. These analytic expressions for the eigenpairs have not previously appeared in the literature. It is then shown that only the eigenvalues of the two flexure modes are decreased by the lower integration rules that are often applied, thereby causing a more flexible response. Knowing the variation in the eigenvalues with the various integrations then allows the element …

Development Of A Parametric Analysis Microcomputer Model For Evaluating The Thermodynamic Performance Of A Reciprocating Brayton Cycle Engine, Thomas Joseph White

Dissertations and Theses

In this thesis, applicable data from research on IC engines have been adapted to PACE engine designs. Data from studies on heat transfer, friction, and pressure losses, in particular, have been used. Certain parameters which define operation and design characteristics appear to influence PACE engine performance very strongly. Some of the more critical parameters, notably friction and heat transfer coefficients, must be determined experimentally if accurate model results are to be expected. Pressure ratio, compressor RPM, and maximum combustor temperature, the independent operating parameters, also have a dramatic effect on engine performance. Other design or operating characteristics and working fluid …

An Update To The Mitre/Wpi Space Shuttle Prgoram: Gascan G-408, Fred J. Looft, William W. Durgin

Office of the Provost Scholarship

The objective of the MITRE/WPI Space Shuttle Program was to develop a set of scientific meaningful experiments that could be flown in a Get Away Special Canister. currently, the first GASCAN is finished (G-408) and ready to be launched. The program has been so successful that the design and development of a second set of experiments has been started (G-533). This paper will describe and summarize both of these programs.

Radiant Barriers: A Question And Answer Primer, Florida Solar Energy Center, Philip Fairey

FSEC Energy Research Center®

Attic radiant barriers made of aluminum foil are becoming a popular way for homeowners to save energy and money in Southern states. They are increasing in popularity for two reasons. First, tests by the Florida Solar Energy Center and other groups show that they work. Second, manufacturers are improving the quality of radiant barrier materials.

To most homeowners, attic radiant barriers are a new energy conservation concept; many of them have questions about how radiant barriers work and how to use them. This Energy Note answers some of the most commonly asked questions. It also recommends ways to install radiant …

A Study Of Flow Separation In Transonic Flow Using Inviscid And Viscous Cfd Schemes, James Andrew Rhodes

Mechanical & Aerospace Engineering Theses & Dissertations

A comparison of flow separation in transonic flows is made using various computational schemes which solve the Euler and the Navier-Stokes equations of fluid mechanics. The flows examined are computed using several simple two-dimensional configurations including a backward facing step and a bump in a channel. Comparison of the results obtained using shock fitting and flux vector splitting methods are presented and the results obtained using the Euler codes are compared to results on the same configurations using a code which solves the Navier-Stokes equations.

The Effects Of A Mandatory Early Shutdown Of Maine Yankee, Maine State Planning Office

Maine Collection

The Effects of a Mandatory Early Shutdown of Maine Yankee

Maine State Planning Office - Richard Silkman, Director (September 1987).

Contents: Introduction / Legal Issues / Economic Issues / Health and Environmental Issues / Conclusions / Appendices

A Turbulence Model For The Heat Transfer Near Stagnation Point Of A Circular Cylinder, Mounir B. Ibrahim

Mechanical Engineering Faculty Publications

A one-equation low-Reynolds number turbulence model has been applied successfully to the flow and heat transfer over a circular cylinder in turbulent cross flow. The turbulence length-scale was found to be equal 3.7y up to a distance 0.05δ and then constant equal to 0.185δ up to the edge of the boundary layer (wherey is the distance from the surface and δ is the boundary layer thickness).

The model predictions for heat transfer coefficient, skin friction factor, velocity and kinetic energy profiles were in good agreement with the data. The model was applied for Re ≤250,000 and Tu_{∞ …}

Topology And Grid Adaption For High-Speed Flow Computations, Jamshid Samareh Abolhassani

Mechanical & Aerospace Engineering Theses & Dissertations

This study investigates the effects of grid topology and grid adaption on numerical solutions of the Navier-Stokes equations. In the first part of this study, a general procedure is presented for computation of high-speed flow over complex three-dimensional configurations. This includes the grid generation and solution algorithm for Navier-Stokes equations in a general three-dimensional curvilinear coordinate system. The flow field is simulated on the surface of a Butler wing in a uniform stream. Results are presented for Mach number 3.5 and a Reynolds number of 2,000,000. The O-type and H-type grids have been used for this study, and the results …

Procedures For Calculating Natural Ventilation Airflow Rates In Buildings. 03-87, Florida Solar Energy Center, Subrato Chandra

FSEC Energy Research Center®

This is the final report of ASHRAE research project 448-RP "Building Pressure Distribution for Natural Ventilation" initiated in October 1985. The objective of the research was to review the worldwide data on building pressure coefficient and to assimilate the data for use in hourly calculation of natural ventilation airflow rates in buildings. This report is organized in two parts. Part 1 is written for the user who wants to use the information. Part 2 provides the background and research data analysis which was conducted to come up with the Part 1 information.

Stress Analysis Of A Stepped Shaft With A Keyway, Irfan Hussain Sabir

Theses

A stress concentration case which is encountered in practice more than any other is the shoulder fillet. Shafts, axles, spindles, rotors etc., usually involve, in each case, a number of diameters connected by shoulders with fillet radii and very often it is necessary for a keyway to be near a shoulder. The objective in this study is to analyse the stresses in a shouldered shaft with a keyway subjected to an axial tensile load and to study the dependence of the keyway-end stresses on the distance between the shoulder fillet and the keyway end. This is done by performing a …

Field Data Delivery - Thermal Performance Field Monitoring Of Various Conservation Construction Techniques. Final Report., Florida Solar Energy Center, Charles Cromer

FSEC Energy Research Center®

No abstract provided.

Evaluation And Improvement Of Production Quality Performance Application At Hadisolb, Helmy Nada

Archived Theses and Dissertations

No abstract provided.

Deformation And Fracture Of Zinc-Aluminium Alloys Under Static And Dynamic Compressive Loading, Hanadi A Ghoneim

Archived Theses and Dissertations

No abstract provided.

The Effects Of Nonlinear Damping On The Large Deflection Response Of Structures Subjected To Random Excitation, Chunchu Bhavani Prasad

Mechanical & Aerospace Engineering Theses & Dissertations

Effects of both nonlinear damping and large deflection stiffness are included in the theoretical analysis in an attempt to explain the experimental phenomena of aircraft panels excited at high sound pressure levels; that is the broadening of the strain response peak and the increase in modal frequency. Beams and symmetrically laminated plates subjected to acoustic excitation are considered in the analyses. The excitations are ergodic and Gaussian with zero mean. A polynomial containing both linear and nonlinear damping terms is considered as a damping model. Galerkin's method is used to derive modal equations. Direct equivalent linearization is used to solve …

A Numerical Study Of Three-Dimensional Vortex Breakdown, Robert Edward Spall

Mechanical & Aerospace Engineering Theses & Dissertations

A numerical simulation of vortex breakdown using the time-dependent Navier-Stokes equations was performed. Unlike previous studies, the numerical algorithm, formulated in terms of the velocity and vorticity, was not restricted to axisymmetric flows. Prototype vortices were parameterized in terms of their Reynolds number and Rossby number. Two cases were studied extensively. In one case, a vortex was imbedded in a uniform free stream. In the other case, the axial velocity of the free stream was decelerated in the streamwise direction. For both cases breakdown occurred when the Rossby number was below a critical value. Vortex lines, particle traces and velocity …

Experimental Study Of Shock Wave Interference Heating On A Cylindrical Leading Edge, Allan R. Wieting

Mechanical & Aerospace Engineering Theses & Dissertations

An experimental study of shock wave interference heating on a cylindrical leading edge representative of the cowl of a rectangular hypersonic engine inlet at Mach numbers of 6.3, 6.5, and 8.0 is presented. Stream Reynolds numbers ranged from 0.5 x 10⁶ to 4.9 x 10⁶ per foot and stream total temperature ranged from 2100 °R to 3400 °R. The model consisted of a 3-inch-diameter cylinder and a shock generation wedge articulated to angles of 10, 12.5, and 15 degrees. The primary goal of this study was to obtain a fundamental understanding of the fluid mechanics of shock wave …

Finite Element Methodology For Nonlinear Free And Harmonic Forced Vibrations Of Beam And Plate Structures, Kamolphan Decha-Umphai

Mechanical & Aerospace Engineering Theses & Dissertations

The literature and experiments have shown that nonlinear vibrations produce significant effects in structural analysis, especially the frequency-amplitude-force relation and the analysis of strain. An analysis was developed to predict both the frequency-amplitude-force relation and strains of beam and plate structures. Two finite element methods were developed, namely, the iterative single-mode method (method I) and the multiple-mode method (method II). The harmonic force matrix was developed to analyze nonlinear forced vibrations. Nonlinear free vibration was a special case of the general forced vibration by setting the harmonic force matrix equal to zero. The harmonic force matrix represents the external applied …

The Use Of Ultrasound Imaging In The In-Vivo Determination Of Normal Human Arterial Compliance, Lauren I. Stratouly, Paul A. Cardullo, Frederick A. Anderson Jr., William W. Durgin, H. Brownell Wheeler

Office of the Provost Scholarship

Elastic properties of major arteries were measured in vivo in ten normal volunteers, age 26 to 44 years (mean = 32 years). A B-mode ultrasound imager was used to noninvasively measure mean diameter and pulsatile diameter change at five locations along the main arteries in the abdomen and the lower extremities. Together with pulsatile pressure (measured by the auscultatory method), strain (ε), compliance (C) and the pressure-strain elastic modulus (Ep l/C) were calculated. Ep increased significantly along the arterial tree; mean values (x10⁵ N/m^-2 ) were: 0.99 aorta, 1.21 common iliac artery (CIA), 1.43 common femoral artery (CFA), …

Heat Pipe Application Program, Florida Solar Energy Center, Mukesh Khattar

FSEC Energy Research Center®

The Florida Solar Energy Center has begun a project to develop a high efficiency air conditioner/dehumidifier using heat pipes between the warm return and cold supply air streams. Such systems will save energy in hot, humid climates.

Tone Generation By Flow Past Deep Wall Cavities, D. D. Erickson, William W. Durgin

Office of the Provost Scholarship

Flow past deep wall cavities exhibits strong interaction with the standing wave system in the cavity. The shear layer separating the exterior flow from the cavity flow supports instabilities which excite the normal cavity modes. In turn, the cavity wave system reinforces the instabilities. Experimental studies have shown that two distinct instability modes are encountered as the external velocity is increased. The pressure coefficient versus Strouha1 number behavior reveals two maxima which correspond to different instability modes of the shear layer. Flow visualization studies have shown that these modes correspond to distinct shear 1ayer vortex structures. At high velocities, single …

Thermomechanical Design Criteria For Zr02-Y203 Coated Surfaces, J. Padovan, Benjamin T.F. Chung, Glen E. Mcdonald, Robert C. Hendricks

Mechanical Engineering Faculty Research

Thermocycling of ceramic-coated turbomachine components produces high thermomechanical stresses that are mitigated by plasticity and creep but aggravated by oxidation, with residual stresses exacerbated by all three. These residual stresses, coupled with the thermocyclic loading, lead to high compressive stresses that cause the coating to spall. In the paper a ceramic-coated gas path seal is modeled with consideration given to creep, plasticity, and oxidation. The resulting stresses and possible failure modes are discussed.

Experimental And Theoretical Studies On Design Calculations For Latent Heat Storage, Dieter Lindemann

Open Access Theses

Research was conducted to obtain design data of latent heat-of-fusion thermal energy storage (LHTES) devices. The devices studied utilize a porous medium (PM) to increase the effective conductivity of the storage system. Therefore the melting and freezing process is accelerated. Metal shavings and metal spheres were used as porous media and water as the phase change medium (PCM). A simple experimental method to measure the conductivity of a water-metal mixture or ice-metal mixture was applied to obtain conductivity data. These measurements can be considered fairly accurate because measured conductivity of pure water and of pure ice agreed very well with …

Energy Transmission Into The Human Hand From Vibrating Tools, Douglas D. Reynolds

Mechanical Engineering Faculty Research

A method for calculating power transmitted to the hands of operators who use vibrating hand tools is presented. Results that relate to a comprehensive multidiscipline NIOSH field study of several hundred chipper and grinder workers who used pneumatic hand tools are discussed. These results indicated that the total power in the frequency range of 6.3 to 1000 Hz transmitted to the hand ranged from 1080 to 7230 J/s for the chisel and from 0.852 to 157 J/s the handle of chipping hammers. For pneumatic grinders the power transmitted to the hands of the tool operators was in the range of …

Effect Of Material Parameters On The Initiation And Growth Of Adiabatic Shear Bands, R. C. Batra

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The thermomechanical problem involving simple shearing of a finite slab made of an isotropic and viscoplastic material is studied with the objective of finding the effect of the strain hardening parameter, strain-rate hardening parameters, thermal softening coefficient and thermal conductivity on the initiation and growth of adiabatic shear bands. The body is placed in a hard loading device, i.e., the velocity is prescribed at its top and bottom surfaces. A shear band is presumed to have formed if the addition of a perturbation in the temperature at the onset of plastic flow results in a localization of the shear strain. …

The Force On A Lattice Defect In An Elastic Body, R. C. Batra

Mechanical and Aerospace Engineering Faculty Research & Creative Works

It is shown that the force on a lattice defect in an elastic body is, like the force on a disclination in a nematic liquid crystal, a real force which, for equilibrium, must be balanced by an external force applied to the closed surface enclosing the defect. © 1987 Martinus Nijhoff Publishers.

Fluidized-Bed Gasifier Engine System Using Rice Hulls, Luis Cruz Baja

Masters Theses

"The operation of a fluidized-bed gasifier using rice hulls and a spark-ignition, internal combustion (IC) engine on product gas at the optimum reactor conditions and on gasoline produced generator loads of 6.7 KWe and 10.5 KWe at average speeds of 1740 RPM and 1785 RPM and thermal efficiencies of 12.7% and 13.8%, respectively. The diesel engine operation on dual diesel fuel oil (DFO) product gas and 100% DFO generated 8.0 KWe and 8.3 KWe at 1416 RPM and 1552 RPM and thermal efficiencies of 10.2% and 20.2% respectively. The gasoline engine could be run on 100% product gas while the …

Issues In The Design And Implementation Of Expert Systems, Clive L. Dym

All HMC Faculty Publications and Research

This article discusses the issues that arise in the design and implementation of expert systems. These issues include: task selection; the stages of development of expert system projects; knowledge acquisition; languages and tools; development and run-time environments; and organizational and institutional issues. The article closes with some speculation about the future development of expert systems.