Digital Commons Network^™

Rebuilding For Efficiency: Improving The Energy Use Of Reconstructed Residences In South Florida, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

On August 24th, 1992, Hurricane Andrew devastated a large part of South Dade County in Florida. With over 35,000 homes to be rebuilt, there is interest in seeing if these reconstructed residences can be made more energy-efficient.

This report provides a comprehensive assessment of potential energy efficiency improvements for both new and existing homes in South Florida. Over forty energy-efficiency measures were considered in the analysis. Many homes in the effected zone experienced damage to their windows, roofs and the surrounding landscape. As a result, the analysis closely examined options associated with these design aspects. All major end-uses of electricity …

Rewet Performance Of A Rectangular Grooved Heat Pipe Wick After Gravitationally Induced Dryout, Lowell S. Hawthorne

Theses and Dissertations

The effects of increased acceleration forces on the transient dryout and rewet performance of an axial groove heat pipe wick were experimentally studied using inclination to simulate increased acceleration forces. Two durations of increased acceleration were investigated, one being less than the time required for the groove to reach steady-state dryout conditions, the other being sufficient to ensure the groove had reached steady-state dryout conditions. The groove's extent of dryout was found to be greater at increased levels of acceleration. The period of time required for the groove to rewet after an acceleration induced dryout increased as acceleration increased. The …

Passive Damping Of A Solar Array, Mark A. Scharpen

Theses and Dissertations

This study was an attempt to conceptualize, design, build, and test a constrained layer damping device that uses mechanical advantage for the purpose of increasing the damping of transient vibration of a five-bay planar truss. The aluminum truss was clamped to a fixed support and simulated a solar array. A conventional constrained layer treatment was designed, built, and tested to serve as a benchmark for comparison. For the conventional treatment, Plunkett and Lee's segmented constraining layer technique was used. The improved device, two three-layer sandwich beams spanning the two bays nearest the built-in end, were supported several inches away from …

Vibration Suppression In Large Flexible Space Structures Using Active Control Techniques, Chad T. Matheson

Theses and Dissertations

This report investigates the use of active vibration control techniques applied to the PACOSS Dynamic Test Article as an experimental structure. In the course of the research, a mathematical model of the lightly damped experimental structure was created based on experimental data. This model was used in the design of two classes of controllers. The first class is pure rate feedback of the structure's measured states such that global stability is insured. The second type of controller investigated was an optimal controller (LQG) that was created using the truncated mathematical model. The rate feedback controller showed significant improvements in the …

Flow Excited Acoustic Resonance In A Deep Cavity: An Analytical Model, William W. Durgin, Hans R. Graf

Office of the Provost Scholarship

Flow past the opening of a deep cavity can excite and sustain longitudinal acoustic modes resulting in large pressure fluctuations and loud tone generation. An analytic model of the interaction of the free stream with the acoustic flow field using concentrated vortices in the shear layer is proposed. The model includes a computation of the power transferred by the traveling vortices to the acoustic oscillation in the cavity. Experimentally measured values for the vortex convection velocity and phase are used to enable calculation of the ensuing oscillation amplititude and frequency ratio. The radiated acoustic power is calculated using the model …

Expert System For The Injection Molding Of Engineering Thermoplastics, Tzy-Cherng Jan

Dissertations

Injection molding of engineering thermoplastics is the most widely used manufacturing method in industry. It is a priority to maintain a deviation-free operating environment to ensure high quality, low cost manufacture. An expert system for the injection molding of engineering thermoplastics has been investigated. The system can be used to attenuate the deviations experienced during the injection molding of engineering thermoplastics. The system is coded in C programming language.

The resolution procedures of this system include two stages such as the definition of declarative knowledge and the procedure of corrective actions. In the definition of declarative knowledge, all of the …

Errors In Constant-Velocity Shaft Couplings, Philip M. Remington

Theses

A Multiloop spatial system of rotations is used to represent a shaft coupling, allowing a transmission plane which may deviate from the plane of symmetry to be specified. The plane of transmission, for intersecting input and output shaft axes, is the locus of intersections of screw axes that compose the system. By prescribing the transmission plane outside of the plane of symmetry (commonly called the "homokinetic plane" or "bisecting plane") to pecified orientations, a phase shift between the input and output shaft rotational displacements will he quantified. The rotational phase shift between the input and output shafts can be evaluated …

Automatic Motion Analysis Of Colliding Spheres, John Vijayakumar Caesar

Theses

Motion analysis is useful to compute linear and angular velocities and acceleration of an object from a sequence of images. This thesis is part of an investigation to compute the translation and rotation velocities needed to determine the collision parameters of two colliding spheres. This involves the tracking of the spheres and feature points on the spheres over a time interval. An experimental setup releases two spheres such that they collide and a high speed imaging system, i.e., Kodak Ektapro 1000 is utilised to record the motion of the spheres. The imaging system is capable of recording at a speed …

Uses And Applications Of Artificial Intelligence In Manufacturing, Manojkumar H. Desai

Theses

The purpose of the THESIS is to provide engineers and personnels with a overview of the concepts that underline Artificial Intelligence and Expert Systems. Artificial Intelligence is concerned with the developments of theories and techniques required to provide a computational engine with the abilities to perceive, think and act, in an intelligent manner in a complex environment.

Expert system is branch of Artificial Intelligence where the methods of reasoning emulate those of human experts. Artificial Intelligence derives it's power from its ability to represent complex forms of knowledge, some of it common sense, heuristic and symbolic, and the ability to …

Development Of The Interface Between Cad And Waterjet Nc Systems, Sivayasivan Sambandan

Theses

There has been a continuous need in the present to develop softwares that provide interface between cutting machines and computer control. There involves a number of complex stages from the birth of an algorithm, to develop such software, till the end where it successfully gets tested and implemented. Cutting Path Simulation (CPS) is a partially developed software designed to model 2-d and 3-d objects and down load them to water jet cutting machine. Additional menus were created in the software to perform specific functions. Bugs that existed in the previously done work were removed. Investigation was conducted on the feasibility …

Computation Of Collision Parameters Of Spheres By Computer Vision, Sumit Sen

Theses

Collision parameter evaluation of rigid spherical particles requires estimation of pre- and post-impact position, velocity and angular velocity vectors of colliding particles. A three dimensional experimental technique is devised where the instantaneous position and orientation of the particles are determined by analyzing frames obtained through high speed video imaging system. Since the image obtained is two dimensional, a mirror setting is designed to capture two orthogonal views of collision in order to estimate motion in depth. The translational velocity vector is determined from the position information extracted through application of available image analysis techniques over two time frames of digitized …

Application Of Desktop Manufacturing System (Sla) For The Manufacturing Of A Centrifugal Pump Impeller Using Cad (I-Deas), Wasimuddin Azam Muhammad Syed

Theses

Desktop Manufacturing (DTM) systems which combine personal computer, laser and other technologies are being used to sculpt objects from computer generated models created on computer aided design (CAD) workstations. As a member of DTM systems, StereoLithography Apparatus (SLA) transforms 3-dimensional designs into a 3-D output. This can substantially reduce the time required to produce a prototype through the process of photopolymerization. The process involves the transfer of a liquid plastic monomer into a solid polymer by exposing it to ultraviolet light.

Although the process looks productive, inefficiencies can occur, if incorrect parameters are selected before its application for a particular …

Modeling, Evaluation, And Control Of A Flexible Manufacturing Cell Using Petri Nets, Glenn Arthur Thorniley

Theses

This thesis describes the usefulness of Petri nets in modeling, evaluating, and controlling a Flexible Manufacturing Cell (FMC). The basics of Petri net theory are explained and a specific FMC is examined. First, the FMC is modeled. The purpose of modeling is to facilitate the evaluation and provide a framework on which the control methodologies can be applied. The objective of the evaluation is to determine how the FMC would benefit most by replacing or adding equipment. Several ideas on control are combined to form a useful framework for the designing of the control net. With this framework the control …

Artificial Neural Networks For Robotics Coordinate Transformation, Stephen Aylor, Luis Rabelo, Sema E. Alptekin

Industrial and Manufacturing Engineering

Artificial neural networks with such characteristics as learning, graceful degradation, and speed inherent to parallel distributed architectures might provide a flexible and cost solution to the real time control of robotics systems. In this investigation artificial neural networks are presented for the coordinate transformation mapping of a two-axis robot modeled with Fischertechnik physical modeling components. The results indicate that artificial neural systems could be utilized for practical situations and that extended research in these neural structures could provide adaptive architectures for dynamic robotics control.

Analysis Of Heat Pump Cycles Using Thermodynamic Equations Of State, Stephen C. Ericson

Mechanical & Aerospace Engineering Theses & Dissertations

In this study, thermal performance of heat pump cycles is analyzed by employing several equations of state. The analysis presented here is particularly useful for applications where refrigerant properties need to be calculated from a thermodynamic equation of state. Such a situation, for example, would arise during a long-term numerical simulation of a solar-assisted heat pump system. In these cases, the direct use of thermodynamic property tables of refrigerants would not be possible in a computational procedure. The approach of using equations of state to predict thermodynamic properties is also useful for applications where new refrigerants or blends of refrigerants …

Transient Simulation Of A Trombe Wall Passive Heating System Coupled To A Thermally Stratified Room, Ali Saleh Kheireddine

Mechanical & Aerospace Engineering Theses & Dissertations

Thermal performance of a Trombe-wall space heating system has been studied numerically for one-day and multiple-day periods. This study analyzes the system performance by simultaneously considering the coupled nature of the channel convection, wall heat conduction and transient room energy balance. A computer program has been written and implemented to assess the effects of system parameters, weather conditions and peak temperature control strategies on the system performance.

The system performance is influenced by such system parameters as the storage wall thickness, channel width and the temperature stratification in the room. Increasing the wall thickness decreases the temperature swings considerably, but …

A Fracture Mechanics Analysis Of A 38 Inch Diameter Hot Pressed Beryllium Telescope Mirror, Phillip L. Brown

Mechanical & Aerospace Engineering Theses & Dissertations

A 38 inch diameter hot pressed beryllium telescope mirror was analyzed for structural integrity using finite-element modeling and a fracture mechanics analysis program, ZIP3D, developed for three-dimensional (3-0) solid and cracked bodies. The calculation of stress and mixed-mode fracture mechanics parameters for the mirror critical stress area was the objective of the mirror analysis.

Finite-element modeling for ZIP3D solution was performed in two stages. The first stage modeling modeled the mirror configuration on a global basis for calculation of accurate nodal displacements. The second stage modeling reduced the modeled mirror configuration to a set of localized models for calculation of …

Solutions Of The Heat Conduction Equation In Multilayers For Photothermal Deflection Experiments, William A. Mcgahan, Kevin D. Cole

Department of Mechanical and Materials Engineering: Faculty Publications

Exact expressions are presented for the deflection of a laser beam passing parallel to and above the surface of a sample heated by a periodically modulated axisymmetric laser beam. The sample may consist of any number of planar films on a thick substrate. These exact expressions are derived from a local Green’s function treatment of the heat conduction equation, and contain an exact analytical treatment of the absorption of energy in the multilayered system from the heating laser. The method is based on calculation of the normal component of the heat fluxes across the layer boundaries, from which either the …

Experimental Investigation Of Crossflow Instability Waves In Rotating Disk Flow, Alan E. Blanchard

Mechanical & Aerospace Engineering Theses & Dissertations

For the past 40 years, the crossflow (or inflectional) instability associated with rotating disk flow has been generally assumed to be a pure vortex that is fixed with respect to the disk; however, the terms "wave" and "vortex" have also been used interchangeably throughout the computational and experimental literature to describe this instability. Through the use of both hot-wire surveys and smoke-wire flow visualizations in the present investigation, the existence of crossflow instability waves prior to vortex formation has been shown. The results of the hot-wire surveys and smoke-wire flow visualizations for both a "clean" disk case and a disk …

Neural Modeling And Control Of A Distillation Column, James Edward Steck, K. Krishnamurthy, Bruce M. Mcmillin, Gary G. Leininger

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Control of a nine-stage three-component distillation column is considered. The control objective is achieved using a neural estimator and a neural controller. The neural estimator is trained to represent the chemical process accurately, and the neural controller is trained to give an input to the chemical process which will yield the desired output. Training of both the neural networks is accomplished using a recursive least squares training algorithm implemented on an Intel iPSC/2 multicomputer (hypercube). Simulated results are presented for a numerical example.

Fsec 3.0: Florida Software For Enervironment Computation: V3.0 Draft User's Manual. 01-92, Florida Solar Energy Center, Alp Kerestecioglu

FSEC Energy Research Center®

FSEC 3.0 was developed to support research. It is a general-purpose software package especially designed to simulate complex building science problems. The program offers several unique features.

The major feature is its ability to solve user-defined systems of governing equations. Up to 250 coupled differential equations and their corresponding boundary conditions may be either selected from libraries or defined by the user. The equations may be linear or nonlinear; spatially-lumped or spatially-distributed; steady-state or transient; ordinary or partial. The structure of the software also allows users to incorporate their own routines or programs. Thus, researchers may define their specific problem …

A Virtual-System Concept For Exergy Analysis Of Flow Network Plant; Part Ii: Exergetic And Exergonomic Analysis Illustration, Jim Mcgovern, Francis O'Toole

Conference Papers

This paper is a continuation of Part I — Principles, to which it refers extensively. The virtual system concept and the methodology introduced in Part I are illustrated by means of a numerical example. This is an exergetic and exergoeconomic analysis of the CHP steam plant that was described in Part I without operating values and parameters. Matrix methods developed by Valero et al. (1986) are adapted to the new concept. It is shown that these methods are made simpler and less subjective. Bond-graph-type diagrams for exergetic and economic costs are presented.

Interface Cavitation Damage In Polycrystalline Copper, Brent L. Adams, David P. Field

Faculty Publications

The authors acknowledge the support of the Office of Basic Energy Sciences of the United States Department of Energy. Determination of an interface damage function (IDF) from a stereological procedure similar to that presented by Hilliard is described. The mathematical and experimental simplicity of the method is utilized in measuring an IDF for polycrystalline copper crept at 0.6T sub m under uniaxial tension. Whereas previous work focused on a five parameter description of the local state of a grain boundary, the domain of the IDF is increased to eight degrees of freedom in the present study to include the complete …

Investigation Of Waterjet-Workpiece Interaction, Hung-Yuan Li

Dissertations

The objective of this research is to develop new knowledge related to the fundamental physical phenomena of waterjet machining of ductile materials, and to use this knowledge to construct a numerical analysis model. The resulting knowledge will enable enhancement of waterjet cutting efficiency.

Experimental study of fundamental mechanisms and the acquisition of the data detailing micro and macro scale phenomena which occur during the machining process is carried out. It is shown that the material damage mechanism associated with waterjet machining is erosion cavitation which initiates ultrasonic stress wave propagation in the workpiece. Fatigue, an important element in producing material …

Development Of Prediction Technique For The Geometry Of The Abrasive Waterjet Generated Kerf, Yichung Chung

Dissertations

This study is concerned with the development of a practical and accurate technique for off-line determination of the variables characterizing the macro-geometry of the kerf generated in the course of abrasive waterjet (AWJ) machining of ductile materials. The study involved generation and processing of a database relating operational conditions with kerf dimensions. The total number of generated samples exceeded 1500.

A physical model relating the process results with operational conditions was constructed and used for the selection of a statistical technique for analysis of the acquired experimental information. The semiempirical model developed here is based on a simple theoretical model …

Structural Reliability Using Finite Element Method, Che-Chen Liou

Dissertations

During the last decade, structural reliability theory has been treated in a large number of research papers; therefore, from being a subject only well known by a relatively small number of researchers, it has become an important engineering discipline. From the application point of view, many practical applications have been made successfully.

In this dissertation some important fundamental concepts in statistics and in reliability theory are presented. The concept of failure mode can be defined as: A set of failed elements turn a structure into a mechanism. Usually, a structure has many possible failure modes; therefore, it will be necessary …

Computational Aspects Of A Three Dimensional Non-Intrusive Particle Motion Tracking System, Avadhani S. Ashok

Theses

Development of a technique for non-intrusive particle motion tracking in three dimensions is considered. This technique is based on the principle of magnetic induction. In particular, the determination of the position and onentation of the particle from the information gathered is the pnncipal focus of this thesis. The development of such a system is motivated by the need to understand the flow patterns of granular material. This is of cntical importance in dealing with problems associated with bulk solids flows which occur in almost all industries and in natural geological events. A study of the current diagnostic techniques reveals the …

Local Stress Due To A Radial Loading At Nozzle-Pipe Connection With Different Thickness, Guosheng Lu

Theses

This thesis presents an analysis using the finite element method of the local stress at the nozzle and pipe connection subjected to a radial loading.

In this study, the local stress factor (for membrane and bending stresses) is presented in a series of plots with beta (nozzle radius/pipe radius) values ranging from 0.1 to 1.0 and gamma (pipe radius/wall thickness) values ranging from 10 to 100. The membrane and bending stresses in longitudinal and circumferential directions of the run pipe are computed as a function of the dimensionless parameters, beta and gamma.

For a given external radial loading with different …

Head-Spine Finite Element Computer Model On A Work-Station, Kay F. Schilli

Opportunities for Undergraduate Research Experience Program (OURE)

In this project, the head-cervical spine finite element computer model has been modified and made portable on the Apollo work-station. The program was developed to aid the researcher in analyzing the simulated behavior of the human spine. The modifications in the computer program have been made in order to utilize the finite element code for continuation of further research.

Unsteady Euler And Navier-Stokes Computations Around Oscillating Delta Wing Including Dynamics, Ahmed Abd-El-Bar Ahmed Salman

Mechanical & Aerospace Engineering Theses & Dissertations

Unsteady flows around rigid or flexible delta wings with and without oscillating leading-edge flaps are considered. These unsteady flow problems are categorized under two classes of problems. In the first class, the wing motion is prescribed a priori and in the second class, the wing motion is obtained as a part of the solution. The formulation of the first class includes either the unsteady Euler or unsteady Navier-Stokes equations for the fluid dynamics and the unsteady linearized Navier-displacement (ND) equations for the grid deformation.

The problem of unsteady transonic flow past a bicircular-arc airfoil undergoing prescribed thickening-thinning oscillation is studied …