Engineering Commons^™

A Survey Of Material, Process, And Operator Requirements Of Midwestern United States Laser Job Shops, Eric Jaeckel

Graduate Research Papers

Managers of seven (7) midwestern United States laser job shops were interviewed to assess the material, process, and operator requirements of each particular shop. The seven shops were located in a six (6) state area including Illinois, Indiana, Iowa, Minnesota, Ohio, and Wisconsin,

It was found that mild steel and ceramic were the most common materials processed. Cutting, marking/scribing/etching, and drilling were the most common types of processing and gas lasers were six times more popular than solid state lasers. Operator training should include materials science, electronics, optics, and computer programming.

Computation Of 2-D And 3-D Natural Convection Heat Transfer In Closed And Vented Cavities, T. O. Mohieldin

Mechanical & Aerospace Engineering Theses & Dissertations

The natural convective heat transfer in closed and vented cavities has been studied numerically, using the primitive variables formulation. A two-and three-dimensional enclosure, and a two-dimensional Trombe Wall channel geometries are considered. The flow has been assumed to remain Laminar, and Boussinesq approximation is invoked for solving the governing equations, The finite-difference method used in this study, is based on the SIMPLER algorithm which uses a combination of central and upwind differencing scheme to obtain stable numerical results.

For both geometries, namely the closed and vented cavities, the fundamental nature of the fluid dynamic and heat transfer characteristics is revealed …

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.

Wear And Development Of Wear Testing Methodology, Tirumalai S. Suresh

Theses

The existing wear and friction theories, and wear testing methods have been analysed to meet the objective of this study. One of the key factors in the analysis of a wear problem is the computation of wear and friction coefficient for a material, under real operating conditions. A new wear testing methodology has been developed and a wear tester has been designed and assembled. The tests have been performed at constant sliding speed and different applied loads for a Cast-Iron - hardened Steel pair.

Robotic Simulation Package For Personal Computers, Amitava Jana

Theses

A software package for three dimensional wire frame modeling of an educational robot is developed for personal computers. This package can be used by students as well as robot technicians to study basic principles of robot kinematics. The interactive simulation software supports both the joint-level and world-level motion control, enabling user to understand teach-pendant programming as well as robot level off-line programming. The desired orientation and position of the robot hand can also be specified through a homogeneous transformation matrix, allowing an advanced student to learn the concept of world modeling in the design of robot work cells. To help …

On Longitudinal And Transverse Shear Spring Constants At The Juncture Of Piping-Nozzle, Chihwei David Chen

Theses

This thesis investigates the longitudinal and transverse shear spring constants at the juncture of a radial nozzle and a cylindrical shell.

Due to the difficulty of arriving an analytical solution to these constants, the " ANSYS" program has been employed to calculate them numerically. These results are reported in tabulated forms. Plots for these spring constants K_x, K_z in terms of parameters Beta ( nozzle radius / pipe radius ), Gamma ( pipe radius / shell thickness ) and shell thickness are also presented in this thesis. A numerical example is given to facilitate the design analysis.

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 …

Finite Element Stress Analysis Of The Femoral Hip Stem Prosthesis - Bone Interface, Mark C. Buechel

Theses

A three-dimensional finite element model is used to examine the stresses of the femoral hip stem prosthesis and surrounding bone, specifically at the interface between the stem and the bone. Using General Electric's GEOMOD modelling program, 3-dimensional models of the hip stem prosthesis, and both the cortical and cancellous bone, are generated. Due to the complexity of the individual models, General Electric's SUPERTAB modelling program is required to merge the three separate models into one complete model. The model is then broken down into finite elements for analysis. The model assumes isotropic properties to cortical bone and cancellous bone. Several …

Energy Analysis Of A Multistory Office Building Using Bin Method Computer Program, Mohammed Nasim Ghauri

Theses

The consumption of energy by an HVAC system in a high rise office building was investigated by comparing results obtained from ASEAM and Trakload (two microcomputer programs) with the manual calculations and DOE-2 (Department of Energy Program) results obtained by Tishman Research Corporation. The study was performed on the Public Service Building of Newark, New Jersey. It is a 26 story office building, designed to be energy efficient.

The results obtained show that, the energy consumed by the HVAC system is a substantial amount of the total energy used but the controlling factors are electrical lighting and equipment. Both of …

Finite Element Analysis Of The Temperature Field In The Course Of Laser Heating, Moududur Rahman

Theses

This study is aimed at the developement of a computational procedure for the prediction of temperature and the concentration fields in the course of surface processing by high energy beams. The finite element technique is used for the solution of two dimensional problem of heat conduction in a solid subjected to the laser radiation. The preprocessing, solution and the postprocessing were carried out by the use of ANSYS software package. The laser energy was simulated by heat generation at the shallow subsurface or by the temperature of the impingement zone. Equal square elements were used for computations. It was found …

Simulation Of Hvac Systems And Library Building Of New Jersey Institute Of Technology Newark, N.J., Muhammad A. Syed

Theses

The HVCASIM⁺ Building Systems and Equipment simulation program package developed at National Bureau of Standards has been used to simulate the building load and HVAC systems of N.J.I.T. library building, This report describes the procedure and strategy adopted to simulate the library building and the HVAC systems.

The library building has been simulated with two different sets of parameters, first with original design data and then with modifications for energy conservation, which ware suggested by the energy management consultants M/s Engineers Incorporated, as a part of the New Jersey Department of Energy School Grant program.

The results of tho …

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.

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

Archived Theses and Dissertations

No abstract provided.

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

Archived Theses and Dissertations

No abstract provided.

The Cost Effectiveness Of System Response Between Mainframe And Micro Cadam, Dan Rae Teel

Graduate Research Papers

The purpose of this study is to show the cost effectiveness of system response between Mainframe and Micro CADAM.

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 …

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 …

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 …

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 …

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.

Evaluation Of Numerical Inversion Of Laplace Transformed Solutions, Yu-Chwin Lin

Theses

Here, some linear physical systems are analyzed by using the standard Numerical Laplace Transformation and Inversion method, including undamped and damped systems:

1. Undamped system: A bar clamped at one end and at one end free.

2. Damped system: Viscously damped linear discrete system.

The advantage of the Numerical Laplace Transformation method is that it reduces the inversion of the Laplace transformed solution to numerical integration; it makes the problem much easier to solve. In the present work, we also studied a new Numerical Laplace Transformation Inversion method by Wilcox (App.0 and Ref.l). The merit of this new method is …

The Feasibility And Economics Of Resource Recovery Using Municipal Solid Waste, Joachim Aloysius Pinto

Theses

This thesis gives an overview of the feasibility and economics of a resource recovery project. The feasibility study of a resource recovery project is done by analyzing its markets, economics, and environmental aspects. The use of market development, accurate capital and operating cost estimation procedures and environmental impact analysis help in predicting fairly accurately the feasibility of a resource recovery facility and also gives a good estimate of the economics of the project.

The thesis also discusses the different system design that are or were used in waste-to-energy conservation. It is quite evident from the discussion that the only two …

Another Aspect Of Duty Cycling: Effects On Indoor Humidity. 01/18-21/87. 10 P., Florida Solar Energy Center, Mukesh Khattar

FSEC Energy Research Center®

The effects of two readily available air-conditioner control strategies on dehumidification performance are discussed: fan "auto," in which the indoor air circulation fan cycles on and off along with the compressor, and fan "on," in which the fan operates continuously regardless of the on or off status of the compressor. Measured performance data are presented on two air-conditioning systems - a packaged terminal direct expansion, constant volume air conditioner without capacity modulation and a unitary direct expansion air conditioner with dual-speed compressor and indoor air fan motors. Measurements of the condensate removal from the air conditioner as well as its …

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 …

Nebraska Summary: S028 John Deere 2555, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

Nebraska Summary: S032 Massey Ferguson 375, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

Nebraska Summary: S013-S014 Massey Ferguson 3090, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

Nebraska Summary: S035-S036 Massey Ferguson 398, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …