Mechanical Engineering Commons^™

Nebraska Tractor Test Museum Committee Minutes July 21, 1998, Tractor Museum

Lester F. Larsen Tractor Museum: Planning and Development Documents

State Fair Planning Camp Creek Threshers First Newsletter

Development And Realization Of A Single-Mode Optical Fiber Ferrule Mold Insert With Twelve Channels, Hsiharng William Yang

Doctoral Dissertations

A manufacturing process for an optical fiber ferrule mold insert with twelve channels has been established. This research project presents mask design, mask fabrication, deep X-ray lithography exposure, resist developing, nickel electroforming, as well as surface finishing to attain the final result. Deep X-ray mask fabrication methods are explored, including mechanically machined masks, micro-EDM masks, and E-beam written masks. The exposures to pattern resists and electroforming to fabricate nickel molds up to 500 $\mu$m thickness are reported in this study. Nickel structures for the optical fiber ferrule insert with twelve channels made by electroforming are the final products. A practical …

The Optimized Electrostatic Motor, Christopher Lee Rambin

Doctoral Dissertations

The most common means of electrically activated actuation is the electromagnetic motor. All electromagnetic motors have a low output to weight ratio and low energy efficiency. The motor's weight is due to the coils and magnets used to generate propulsion. The energy loss is mainly the result of Joule heating that is inherent with any current driven device. An electrostatic motor offers the potential of significantly less weight and higher energy efficiency. This lower weight characteristic is due to the epoxide material used to construct the major components of its propulsion unit. Greater efficiency results from the reduced Joule heating …

The Effect Of Peer Tutoring On The Test Scores Of Washington High School 9th Through 12th Grade Students Enrolled In Metals/Small Engines Class, Larry D. Harken

Graduate Research Papers

The purpose of this study was to investigate the effect of peer tutoring on the class-average tests scores of Metals/Small Engines students in grades 9-12 at Washington High School, Vinton, Iowa.

Development And Experimental Validation Of An Underwater Manipulator Hydrodynamic Model, Timothy W. Mclain, Stephen M. Rock

Faculty Publications

Hydrodynamic forces can be large and hence have a significant effect on the dynamic performance of underwater manipulation systems. this paper investigates these forces for a cylindrical single-link arm undergoing motions that are characteristics of a robotic manipulator. Based on flow visualization, theoretical analysis, and experimental measurements, a new model is developed that describes these forces. This model differs from previous models in that the drag and added-mass coefficients are state-dependent functions that depend on the distance traveled by the arm. A factor of four improvement in accuracy is demonstrated over standard constant-coefficient models.

The Solution Of Hypersingular Integral Equations With Applications In Acoustics And Fracture Mechanics, Richard S. St. John

Mathematics & Statistics Theses & Dissertations

The numerical solution of two classes of hypersingular integral equations is addressed. Both classes are integral equations of the first kind, and are hypersingular due to a kernel containing a Hadamard singularity. The convergence of a Galerkin method and a collocation method is discussed and computationally efficient algorithms are developed for each class of hypersingular integral equation.

Interest in these classes of hypersingular integral equations is due to their occurrence in many physical applications. In particular, investigations into the scattering of acoustic waves by moving objects and the study of dynamic Griffith crack problems has necessitated a computationally efficient technique …

Successive Galerkin Approximations To The Nonlinear Optimal Control Of An Underwater Robotic Vehicle, Timothy Mclain, Randal W. Beard

Faculty Publications

The application of a new nonlinear optimal control strategy to the station-keeping control of an underwater robotic vehicle is considered. The control approach described and demonstrated here is based upon the numerical approximation of solutions to the Hamilton-Jacobi-Bellman equation. These solutions are computed by an iterative application of Galerkin's method. Preliminary simulation results demonstrating the application of this approach to the control of an underwater vehicle in the horizontal plane are presented.

Vortex Wake And Exhaust Plume Interaction, Including Ground Effect, Ihab Gaber Adam

Mechanical & Aerospace Engineering Theses & Dissertations

Computational modeling and studies of the near-field wake-vortex turbulent flows, far-field turbulent wake-vortex/exhaust-plume interaction for subsonic and High Speed Civil Transport (HSCT) airplane, and wake-vortex/exhaust-plume interaction with the ground are carried out. The three-dimensional, compressible Reynolds-Averaged Navier-Stokes (RANS) equations are solved using the implicit, upwind, Roe-flux-differencing, finite-volume scheme. The turbulence models of Baldwin and Lomax, one-equation model of Spalart and Allmaras and two-equation shear stress transport model of Menter are implemented with the RANS solver for turbulent-flow modeling.

For the near-field study, computations are carried out on a fine grid for a rectangular wing with a NACA-0012 airfoil section and …

Kiln Design And Fuel Wood Consumption In Fish Smoking, E Mushi

Tanzania Journal of Engineering and Technology (TJET)

In this paper. a load flow solution for the Medium Voltage (MY) three-phase radial distribution in delta-delta (A — A) connected network supplying different line topologies such as three phase, phase to phase and single-wire earth return (SWER) networks is presented. The general voltage related network equations are developed using Kirchhoff's voltage and current laws. Development ofa solution to the loadflow analysis applying the developed general voltage related network equations is proposed in order to evaluate the network voltage profile. Various numbers of arrays are developed for the identification of the network under study. The proposed method is a new …

Minutes Of The June 23, 1998 Meeting Of The Friends Of The Tractor Test Museum, Tractor Museum

Lester F. Larsen Tractor Museum: Planning and Development Documents

Updated Membership Listing Foundation Budget Ageless Iron Article

Comparative Summer Attic Thermal Performance Of Six Roof Constructions, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

Florida Solar Energy Center (FSEC) has measured summer attic thermal performance of six roofs at a heavily instrumented test site, the Flexible Roof Facility (FRF). The FRF is a 1,152 square foot (107 m2) building with six roof adjacent test cells which are heavily insulated from each other. Some 233 channels of data were obtained; this includes twenty temperature measurements per cell, extensive meteorological conditions, surface and tower wind speeds and attic humidity and roof surface moisture accumulation. The data were collected over the ASHRAE definition of summer (June - September) to compare cooling season thermal of roofing systems. Six …

Needs Assessment: Photovoltaics In Disasters, Florida Solar Energy Center, William Young

FSEC Energy Research Center®

In recent years, solar energy has been used sporadically for disaster relief. Disaster relief organizations knew very little about photovoltaics; therefore, the technology was not included in their plans or operations. Likewise, the photovoltaic (PV) industry has not been directly involved on disaster teams, and did not aggressively pursue associated markets.

However, the Florida Solar Energy Center (FSEC) and Sandia National Laboratories (SNL) recently completed an energy needs assessment of disaster response, recovery and mitigation activities. The study found that PV is best suited for specialized or dedicated applications that need to operate for long periods of time. This paper …

Frequency Selection Of Wake Flow Behind A Naca 0012 Wing, Han-Wen Lee, Rong-Fung Huang

Journal of Marine Science and Technology–Taiwan

The oscillating flow modes, frequency selection, and response of periodic frequency to change of characteristic flow modes behind a NACA 0012 wing model are studied experimentally. The functional relationships of the dominant mechanisms in limiting ranges of Reynolds number are justified analytically. The oscillating instabilities in wake region possess four characteristic modes: laminar, subcritical, transitional, and supercritical. In viscous effect dominated regime of laminar mode, Strouhal number is inversely proportional to Reynolds number. In inertial effect or pressure gradient dominated regime of supercritical mode, Strouhal remains constant. In regime between limiting cases, Strouhal number increases nonlinearly with Reynolds number and …

Complete Solution Of The Five-Position Synthesis For Spherical Four-Bar Mechanisms, Chen-Chou Lin

Journal of Marine Science and Technology–Taiwan

The objective of this paper is to synthesis spherical four-bar motion and path generators using continuation method (homotopy method). Using continuation method, we may obtain a complete set of the solutions to the problems, and provide mechanism designers with all possible choices which meet the kinematic specifications. In contrast to other local numerical schemes such as Newton method and Powell method which are sensitive to initial guess, continuation method is a global convergence method that guarantee to find all solutions to the equations. In this paper, the problems with four and five precision points will be formulated, solved, and compared …

Measured Energy Savings From Retrofits Installed In Low-Income Housing In A Hot And Humid Climate, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

The Florida Solar Energy Center (FSEC) is metering energy use in a Habitat for Humanity housing development. The objective is to understand the way in which energy is used in low income housing and how it can be effectively reduced.

The ten homes come from a conventional housing project built by in 1993 Habitat for Humanity in Homestead, Florida. The instrumentation was installed in the homes in July of 1994 with over three years of 15-minute data collected on all sites. Data were obtained on seven electrical end-uses (air conditioning, heating, hot water, dryer, range, refrigerator, washer/freezer) as well as …

Monitored Summer Peak Attic Air Temperatures In Florida Residences, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

Florida Solar Energy Center (FSEC) has analyzed measured summer attic air temperature data taken for some 21 houses (three with two different roof configurations) over the last several years. The analysis is in support of the calculation within ASHRAE Special Project 152P which will be used to estimate duct system conductance gains which are exposed to the attic space. Knowledge of prevailing attic thermal conditions are critical to the duct heat transfer calculations for estimation of impacts on residential cooling system sizing.

The field data was from a variety of residential monitoring projects which were classified according to intrinsic differences …

Ventilation, Humidity, And Energy Impacts Of Uncontrolled Airflow In A Light Commercial Building, Florida Solar Energy Center, Charles Withers, Jr.

FSEC Energy Research Center®

A small commercial building was monitored before and after energy saving retrofits to study the impact of retrofits upon ventilation rates, humidity, building pressure and air conditioning energy use. Duct airtightness testing identified severe duct leakage as a significant source of uncontrolled airflow. Differential pressure and infiltration measurements using tracer gas indicated an attic exhaust fan as another significant source of uncontrolled airflow. Duct repair resulted in a 31% drop (30.5 kWh/day) in cooling energy, and an increase in relative humidity from 72% to 76%. Turning off the attic exhaust resulted in an additional 36% energy savings (14.3 kWh/day), including …

Redesigning Engineering Education, William W. Durgin, Edward A. Parrish

Office of the Provost Scholarship

In developing the PLAN, WPI sought to address concerns inherent to its then traditional curriculum that was rigid, unresponsive to differences among students, and was compartmentalized by independent departments so that intellectual growth was fragmented.

The PLAN was an entirely new and different educational program responsive to the needs of students and society while nurturing sensitivity to the ideas and values of our society. It included fundamental departures from the traditional elements of technical education including:
A. The achievement of competence rather than the accumulation of credits.
B. Individual freedom and responsibility in planning the program of study.
C. A …

Evaluation Of The Pv Systems At Martin Power Plant. 07-14-98 (Rev. 07-23-98), Florida Solar Energy Center, Jennifer Skislak

FSEC Energy Research Center®

On June 3, 1998, researchers from the Florida Solar Energy Center (FSEC) conducted a field test of six, independent photovoltaic (PV) systems at the Florida Power and Light (FPL) Martin Power Plant. The weather conditions during test were hazy with a few clouds. This test was performed at the request of FPL to determine the operational status of the PV systems and to provide recommendations for upgrading or repairing these systems. Of the six systems, three were fully operational and were providing power to the grid.

Energy-Efficient Florida Educational Facilities: Improvements To A Portable Classroom At A Volusia County School. Final Report. 06-98, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

An ambitious project by the Florida Solar Energy Center (FSEC) and sponsored by the Florida Department of Education (FDOE) is monitoring the energy use of two adjacent portable classrooms to see how they might be made more energy efficient in a hot-­humid climate. These classrooms have been monitored for one year to collect baseline data before the energy efficient measures are installed. These measures include an efficient lighting system, a new air conditioner, and a reflective white metal roof.

Solar Weatherization Assistance Program, Program Final Report, Volume 1: Main Report. 08-25-98, Florida Solar Energy Center, John Harrison

FSEC Energy Research Center®

The Solar Weatherization Assistance Program (SWAP) was a joint effort of the U.S. Department of Energy (DOE), the Florida Department of Community Affairs (DCA) and the Florida Solar Energy Center (FSEC) to provide solar water heating systems for low-income residents in Florida.

Raising families, incurring everyday bills and purchasing common necessities are all part of daily life that can rapidly drain a family's budget. This is especially burdensome for low-income and elderly residents on a fixed income. A major part of the budgetary concerns are the recurrent and unavoidable electric bills.

In northern colder climates, weatherization programs assist low-income clients …

A Practical Algorithm For Designing H∞ Control Laws, Timothy Mclain, Randal W. Beard

Faculty Publications

We describe an approximation method for the Hamilton-Jacobi-Isaacs (HJI) equation that results in feedback control. The approximation is accomplished via a two-step successive Galerkin approximation scheme. An application of the technique to the control of the forward motion of an underwater vehicle is described.

Fuel Equalized Retargeting For Separated Spacecraft Interferometry, Timothy Mclain, Randal W. Beard, Fred Y. Hadaegh

Faculty Publications

Motivated by NASA's proposed Deep Space 3 interferometer mission, the paper considers the problem of reorienting a constellation of spacecraft such that the total fuel distributed across the constellation is both conserved and expended uniformly. The spacecraft constellation is controlled to reorient as if it were a rigid body. Two approaches to fuel equalization are investigated. The first approach picks a point of rotation a priori that optimizes an objective function that trades off minimum-fuel maneuvers and maneuvers that equalize the fuel. Since the point of rotation is selected a priori and is fixed during the rotation, this approach is …

Analytical And Experimental Study Of Investment Casting With Laser Stereolithography Models, Wen-Long Yao

Dissertations

This dissertation presents an analytical and experimental investigation of ceramic shell cracking during the burnout process in investment casting with internally webbed laser stereolithography (SLA) patterns. Included in the consideration are the cracking temperature of the ceramic shell, the web link buckling temperature, and the glass transition temperature of the epoxy resin. The hypothesis is that shell cracking will occur when the cracking temperature is lower than the glass transition temperature and the web buckling temperature.

An analytical and experimental study has been conducted, with the cross-sectional area, the span length of the web structure, and the shell thickness being …

Automobile Air Bag Inflation System Using Pressurized Carbon Dioxide, Bart Adams

Dissertations

A novel air bag inflator based on the evaporation ofliquefied carbon dioxide was developed. A detailed qualitative model wasestablished on the basis of an extensive experimental study. An integratedquantitative model of this inflator was constructed.

The system was studied by discharging the inflatorinto a tank and measuring pressure and temperature evolution (0-50 ms). Thedispersion of the two-phase spray duringinflation was investigated by high-speed cinematography.

The optimal storage pressure of the liquid CO₂was found to be 2000 psig (at 22 °C). Two distinct inflator behaviors wereidentified. First, at conditions corresponding to an initial entropy below the critical point, atwo-phase …

Robust Fuzzyclustering For Object Recognition And Classification Of Relational Data, Sumit Sen

Dissertations

Prototype based fuzzy clustering algorithms have unique ability to partition the data while detecting multiple clusters simultaneously. However since real data is often contaminated with noise, the clustering methods need to be made robust to be useful in practice. This dissertation focuses on robust detection of multiple clusters from noisy range images for object recognition. Dave's noise clustering (NC) method has been shown to make prototype-based fuzzy clustering techniques robust. In this work, NC is generalized and the new NC membership is shown to be a product of fuzzy c-means (FCM) membership and robust M-estimator weight (or possibilistic membership). Thus …

Design Of An Effective And Timely Product Development Process For Medical Devices, Jean Benoit Almonor

Theses

Effective product development process is one of the most critical issues facing medical devices manufacturing today. There is a need to search for ways to improve or solve the cross organization and company boundaries to enhance the faster release of new medical products to the market. This thesis presents an integrated set of perspectives on the process of new product development of medical devices with dual goals of achieving marketing speed and meet customer satisfaction.

The Attribute Driven Specifications approach described in this thesis, is one of the most valuable tools in the approach to effective product development in medical …

Demanufacturing Metrics For Industrial Fasteners And Disassembly Process, Narendra P. Raj

Theses

As the society progresses towards ecological maturity, the issue of reducing the environmental burden imposed by used products becomes increasingly important Environmental issues are becoming increasingly relevant for product designers and manufacturers. Public awareness of the value and fragility of an intact ecology is constantly growing, and the traditional assumption that the cost of ecological burdens to be shared by a society, as a whole is no longer accepted. Environmental protection legislation requiring manufacturers to "take back" and recycle used products will be a commonplace throughout Europe and the U.S. in the near future.

Demanufacturing involves separating and disassembling a …

Advanced Fenestration And Daylighting Systems, Florida Solar Energy Center, Ross Mccluney

FSEC Energy Research Center®

Advanced fenestration and daylighting systems form an interesting new class of devices and products for introducing natural lighting (daylight illumination) into buildings. They are split into two distinct classes. Advanced fenestration systems are new high-performance glazing and reflecting systems for otherwise conventional windows which offer specialized spectral and/or angular selectivity, intended for improved illumination quantity and quality while managing solar radiant heat gain to meet both human comfort and energy conservation objectives. These spectral and/or angular selectivities can be built into the glazings, incorporated into new objects placed between the panes, or they can be part of objects attached to …

Standards And Verification Protocols For Commissioning Air Flows In Buildings, Florida Solar Energy Center, James Cummings

FSEC Energy Research Center®

Commissioning involves three major elements - 1) process, 2) standards, and 3) protocols to verify compliance with the standards. Process is the step-by-step oversight of and involvement in the design, build, and start-up of the facility, to make sure that the design matches the customer's needs, that the design is consistent with good building science practice, that construction matches the construction documents, and that systems and system interactions are properly tested at start-up. This paper does not address process, rather it focuses on the second and third elements -- standards and compliance protocols. It presents standards related to airtightness, air …