Engineering Commons^™

The Implementation Of Photovoltaic Transportation Devices, Florida Solar Energy Center, William Young

FSEC Energy Research Center®

The Florida Solar Energy Center (FSEC) and the Florida Department of Transportation (FDOT) are currently involved in a program to implement solar electric (photovoltaic) powered applications in the transportation sector. The objective of the program is to encourage the widespread use of cost-effective, transportation related, photovoltaic-powered systems in all areas of traffic control.

Transportation departments have generally relied on conventional practices of using generators, primary batteries, and extensions of utility grid to fulfil their power needs. There exist many remote and conventional electric power requirements within the FDOT that may be effectively satisfied by photovoltaic (PV) power. Applications ranging from …

Active Vibration Control Device, Keith E. Rouch, Sanjiv Tewani, Bruce L. Walcott, Ted R. Massa, Robert W. Stephenson, L. Scott Stephens

Mechanical Engineering Faculty Patents

An active vibration control device for controlling vibration in a cantilevered member and a method for the same are disclosed. The device is comprised of a cantilevered member having a longitudinal axis comprising a sensor mounted near the free end of the member to measure motion of the member in a transverse direction and to produce a corresponding signal. A force generating assembly is mounted to the member near the free end to oppose the measured motion with a force thereby minimizing subsequent motion along the transverse axis caused by vibration.

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 …

Laminar/Turbulent Oscillating Flow In Circular Pipes, Kyung H. Ahn, Mounir B. Ibrahim

Mechanical Engineering Faculty Publications

A two-dimensional oscillating flow analysis was conducted simulating the gas flow inside Stirling engine heat exchangers. Both laminar and turbulent oscillating pipe flow were investigated numerically for Re_max = 1,920 (Va = 80), 10,800 (Va = 272), 19,300 (Va = 272), and 60,800 (Va = 126). The results are here compared with experimental results of previous investigators. Predictions of the flow regime on present oscillating flow conditions are also checked by comparing velocity amplitudes and phase difference with those from laminar theory and quasi-steady profile. A high Reynolds number k-ε turbulence model was used for turbulent oscillating pipe flow. …

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 …

Development Of Knowledge-Based Systems For Aluminum Welding, R. J. Napolitano, H. Kulluk, Mark L. Nagurka, R. P. Martukanitz, P. B. Dickerson

Mechanical Engineering Faculty Research and Publications

No abstract provided.

Hurricane Andrew Photovoltaic Traffic Control Relief, Florida Solar Energy Center, William Young

FSEC Energy Research Center®

On August 24, 1992 Hurricane Andrew damaged and destroyed much of south Florida. The storm destroyed buildings, structures, and traffic devices along the highway. Travel was hazardous with debris in the roadway, traffic signals damaged or not working, and signs missing. This disaster offered a unique opportunity to research and evaluate the potential for using photovoltaic power systems in emergency traffic control situations. This report describes the findings of this study completed by the Florida Solar Energy Center sponsored by the Florida Department of Transportation.

Spaceflight Payload Design, Flight Experience G-408, William W. Durgin, Fred J. Looft, Albert Sacco, Jr., Robert Thompson, Anthony G. Dixon, Dino Roberti, Robert Labonte, Larry Moschini

Office of the Provost Scholarship

Worcester Polytechnic Institute's first payload of spaceflight experiments flew aboard Columbia, STS-40, during June of 1991 and culminated eight years of work by students and faculty. The Get Away Special (GAS) payload was installed on the GAS bridge assembly at the aft end of the cargo bay behind the Spacelab Life Sciences (SLS-l) laboratory. The experiments were turned on by astronaut signal after reaching orbit and then functioned for 72 hours. Environmental and experimental measurements were recorded on three cassette tapes which, together with zeolite crystals grown on orbit, formed the basis of subsequent analyses.

The experiments were developed over …

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.

Notice Of Meetings For Museum Committee In 1992, Tractor Museum

Lester F. Larsen Tractor Museum: Planning and Development Documents

No abstract provided.

Automatic Recognition Of Tool Wear On A Face Mill Using A Mechanistic Modeling Approach, Daniel Waldorf, Shiv G. Kapoor, Richard E. Devor

Industrial and Manufacturing Engineering

A strategy is developed for identifying cutting tool wear on a face mill by automatically recognizing wear patterns in the cutting force signal. The strategy uses a mechanistic model development to predict forces on a lathe under conditions of wear and extends that model to account for the multiple inserts of a face mill. The extended wear model is then verified through experimentation over the life of the inserts. The predicted force signals are employed to train linear discriminant functions to identify the wear state of the process in a manner suitable for on-line application.

Heterogeneity Of Intergranular Damage In Copper Crept In Plane-Strain Tension, Brent L. Adams, David P. Field

Faculty Publications

The authors wish to acknowledge support of this work by the Office of Basic Energy Sciences of the U. S. Department of Energy. An interface damage function (IDF), which statistically describes the area fraction of interface damage as a function of up to eight parameters defining crystallite interfaces, was determined for commercial purity copper specimens crept in plane strain tension. The IDF was determined from stereological parameters measured on plane sections cut through damaged specimens. The eight-dimensional space of the function was investigated by analyzing two-dimensional projections of the complete domain. Certain special interfaces were observed to damage preferentially. A …

Measured Electricity Savings Of Refrigerator Replacement: Case Study And Analysis, Florida Solar Energy Center, Ted Stedman

FSEC Energy Research Center®

There are approximately seven million refrigerator-freezers in the State of Florida. The average demand of these units is at least 1,000 MW. The average life of a residential refrigerator is approximately 20 years (U.S. DOE, 1989). At least 25% of Florida's existing stock are old inefficient units built before the advent of recent appliance efficiency standards. The least efficient are existing models of which approximately 5% of the stock is replaced each year. This represents a significant opportunity for efficiency improvement since recently established standards will greatly improve refrigerator efficiency by 1993 (NAECA, 1987). A number of studies have identified …

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 …

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.

Measurement Of Thermal-Energy Charge-Transfer Rate Coefficient Of Mo6+ And Argon, Victor H.S. Kwong, Z. Fang, Yingtao Jiang, T. T. Gibbons, L. D. Gardner

Electrical & Computer Engineering Faculty Research

The charge-transfer rate coefficient of Mo6+ and argon has been measured at mean ion energies of 8.8 and 1.4 eV using a laser-ablation ion source and an ion trap. The rate coefficient deduced from these measurements is 1.02(0.10)×10-10 cm3 s-1 and appears to be independent of the mean ion energy at this energy range. However, the measured value is an order of magnitude smaller than the Langevin rate coefficient.

A Virtual-System Concept For Exergy Analysis Of Flow Network Plant; Part I: Principles, Jim Mcgovern, Francis O'Toole

Conference Papers

A new type of virtual system, named a flow constraint system (FCS), is proposed to facilitate, clarify, and simplify exergy analyses of plant that involve material flow networks. The need for the virtual system is outlined and the concept is demonstrated by applying it to a CHP steam cycle. The FCS concept allows the physical constraints on the exergy interactions associated with flow streams to be taken into account fully. It also simplifies the treatment of bifurcations in material flows and considerably reduces the need for absolute exergy evaluations. The new concept follows from the work already published by the …

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.

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 …

Experimental Measurement Of Rov Tether Tension, Tim W. Mclain, S M. Rock

Faculty Publications

In the undersea operation of a tethered ROV system, the pilot's ability to control precisely the ROV is often limited by disturbance forces generated by drag due to currents that act either directly on the ROV or indirectly on the ROV through the tether. The objective of this research, which was conducted at the Monterey Bay Aquarium Research Institute (MBARI), was to characterize the magnitude and dynamics of tether forces by measuring them during operation. To achieve this, a tether tension sensor and data logging system were developed. This system was used to measure the forces in the tether of …

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 …

Thermally Induced Stresses In Micro-Chip Mounting Devices, K. J. Mikulcik

Opportunities for Undergraduate Research Experience Program (OURE)

Microchip thermal stress due to the temperature change related to the mounting of a chip to its lead frame was investigated by moire interferometry. Large scale models were made, and the problems of applying a grating to this model at high temperature were addressed without success. Further possibilities, however, remain to be attempted. Moire interferometry was successfully used at room temperature by examining mechanically relieved residual stresses. The results agreed with an analytical approach to stress analysis and also to a finite element analysis. A practical solution to the problem of peeling was found.

Computer Modeling Of A Liquid Fuel Spray, Clement R. Goodin Jr.

Opportunities for Undergraduate Research Experience Program (OURE)

This project was designed to find an accurate and convenient method of computing fuel spray parameters. The project centers around an experimental setup which basically fires a laser beam through a fuel spray mist. A concentric ring detector then measures energy from the scattered light.

A computer code was written which solves a governing equation to give computed values of the energy from scattered light. Comparison of the experimental energy and the computed energy tells how well the fuel parameters of the computer model matches those of the real spray of the experiment. An iteration technique then manipulates the computer …

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.

Behavior Of Composites For The Nasp Project, Robert B. Stone

Opportunities for Undergraduate Research Experience Program (OURE)

It is well known that ceramics are strong, highly heat resistant, refractory materials. Unfortunately, they are brittle and fail catastrophically. However, the strength as well as fracture toughness of ceramics can be greatly improved with the addition of continuous fibers, thus obtaining ceramic matrix composites (CMC). Normally the addition of aligned continuous fibers to a matrix degrades the transverse (the direction 90° to the fiber axes) properties while greatly improving the longitudinal properties. It has been shown that the addition of whiskers to a continuous fiber CMC will improve moduli and strength properties in both the transverse and longitudinal directions. …

Static And Dynamic Testing Of Serpentine Belt Drive Tensioners, John W. Minor

Opportunities for Undergraduate Research Experience Program (OURE)

Serpentine belt drive tensioners are used in virtually every model of automobile produced today. Limited testing has been done to see how the tensioner performs under certain situations. In each case outside influences were either not accounted for or considered not to influence the way the tensioner performed in a given situation. By developing new ways of testing tensioners for static and dynamic characteristics separately, the influence each trait has on the performance of the tensioner can be exactly gauged.

Thermal Buckling Of Composite Tubes, S. Fulkerson

Opportunities for Undergraduate Research Experience Program (OURE)

The object was to design and initiate the use of a fixture capable of testing for pre-buckling deflections in a composite tube under thermal loading. The fixture is to be used on a continuing basis to test three types of composites: (1) glass/epoxy, (2) Kevlar/epoxy, and (3) graphite/epoxy. The course of action chosen was to adapt a fixture designed by Tim Streb and Steve Fulkerson in the spring of 1991. The fixture was completed, and one test was performed. An added responsibility was to initiate a course of action such that the volumetric percentage of fiber in the composite may …

Member Stiffness And Contact Pressure Distribution Of Bolted Joints, Matthew L. Mckay

Opportunities for Undergraduate Research Experience Program (OURE)

Member stiffness and the stress distributions in the bolts and members of bolted joints have been calculated for various bolt sizes, as well as thicknesses and materials of the members. The finite element method has been used to calculate the displacements and the stress distributions in the components of the bolted joint Using axisymmetric elements, the bolted joint could be analyzed as a two dimensional problem. Member stiffness ratios were calculated from the finite element results and compared with those calculated by an existing commonly used theory. The values were comparable for conditions where the theory could be applied. In …

The Simulation Of Tool Path Generation In Milling For Machining Processes, Rickey W. Jennings

Opportunities for Undergraduate Research Experience Program (OURE)

This paper is a report on the progress of this project to create a complete CAD/CAM system. The paper describes the introduction to the simulation package called Vericut. It also discusses the integration of the three packages: AutoCad version 11, PCAPT with APTGEN, and Vericut. The progress of the project to this point is only to the integration of the three packages. The paper also indicates the work which still needs to be completed. The key point of which is the menu system which is the final step in the project.

Instant Centers Of Velocity In A Kinematically Intelligent Blackboard Environment, R. Jeff Fensterman

Opportunities for Undergraduate Research Experience Program (OURE)

This project was part of a continuing expansion of a graphical software environment called "Skimp”, originally developed by Dr. J. K. Nisbett.[l] The final version of this software package will allow the kinematic concepts of an introductory machine dynamics class to be taught exclusively on a blackboard sized projected computer screen. This software package will be used as a teaching aid in the classroom as well as a tutorial for students outside the classroom.

The scope of this project was limited to the concept of instant centers of velocity. This portion is a subroutine accessible during the regular execution of …