Mechanical Engineering Commons^™

Modeling Of Purge Valve Closure, William W. Durgin, Benito Zannini

Office of the Provost Scholarship

In some nuclear reactor containment isolation applications, butterfly valves with pneumatic actuators are used to close pipelines in the event of containment pressure transients resulting from postulated accidents. A model is developed which predicts the closure time history of such valve/actuator systems under prescribed transients. Examples are presented which show the importance of the valve and actuator characteristics. It was found that actuation delays of sufficient magnitude could allow the dynamic torque to exceed the available actuator torque, thus preventing valve closure.

Sun Position In Florida, Florida Solar Energy Center, Ross Mccluney

FSEC Energy Research Center®

Described herein is a procedure for determining the path of the sun through the Florida sky relative to a solar collector array, a window, a skylight or an entire building - information needed by architects, engineers and others for shading and orientation calculations involved in active and passive building design. It can be used for positioning exterior shading devices for maximum benefit. This information can also be used to pinpoint solar collector shading problems.

Open-Cycle Ocean Thermal Energy Conversion, Florida Solar Energy Center, Magdy Girgis

FSEC Energy Research Center®

In May 1983 the Florida Solar Energy Center(FSEC) received $ 328,000 from the federal Solar Energy Research Institute in Colorado to determine the feasibility of an Open-Cycle Ocean Thermal Energy Conversion (OTEC) concept. The objective of the project is to assess the economic and technological viability of the conceptual design of an Open Cycle OTEC power plant. FSEC and Create R&D Inc., Hanover, New Hampshire, bring together complementary skills and experience in resource assessment, component design, system engineering and project management. FSEC also will study possible sites for an OTEC plant in Florida as part of a complementary project funded …

Augmentation Of Free Surface Heat And Mass Transfer Due To Electrostatic Fields, Alan F. Smelewicz, Mark P. Majcher, James B. Nystrom, William W. Durgin

Office of the Provost Scholarship

Experiments were conducted to measure heat transfer rates and mass transfer rates from a water surface in the presence of electrostatic fields of various strengths generated between the water surface and a wire grid above the surface.

Heat transfer rates were determined by the temperature decay after heating the test and control basins. Mass transfer rates were determined by measuring the water loss while holding the basins at fixed temperatures.

It was found that very little increase in transfer coefficients took place for voltages below an onset voltage which depended on atmospheric conditions and test geometry. The heat transfer coefficient …

Photovoltaics: A Question And Answer Primer, Florida Solar Energy Center, Ingrid Melody

FSEC Energy Research Center®

Of all the solar energy technologies, photovoltaics (PV) show the greatest promise for worldwide acceptance and application. Their universal appeal lies in the fact that they generate electricity from the sun. Working photovoltaics have no moving parts, are relatively simple in design, need very little maintenance and are environmentally benign. They simply and silently produce electricity whenever they are exposed to light.

Passive Cooling Ideas For The Southeast, Florida Solar Energy Center, Chris Beck

FSEC Energy Research Center®

A passively cooled home is one which is kept relatively comfortable through natural means. Homeowners in the Southeast have been using passive building techniques in order to live more comfortably during hot, humid seasons since the early 1900's. The concept of designing for minimum use of artificial cooling and heating systems is not new, but with the advent of sophisticated mechanical air-conditioning and heating systems and the availability of inexpensive fossil fuels in the '40s and '50s, builders began bypassing passive techniques. Too many of today's homes are designed with more concern about accomodating a mechanical conditioning system than with …

Saint-Venant's Principle In Linear Elasticity With Microstructure, R. C. Batra

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Toupin's version of the Saint-Venant principle in linear elasticity is generalized to the case of linear elasticity with microstructure. That is, it is shown that, for a straight prismatic bar made of an isotropic linear elastic material with microstructure and loaded by a self-equilibrated force system at one end only, the strain energy stored in the portion of the bar which is beyond a distance s from the loaded end decreases exponentially with the distance s. © 1983 Martinus Nijhoff Publishers.

Designing And Installing Commercial Solar Pool Heating Systems, Florida Solar Energy Center, Douglass E. Root

FSEC Energy Research Center®

Solar heating of swimming pools is an economically attractive utilization of Florida's abundant solar resource. The temperature requirement is lower than that of domestic or service water heating, lower than that for building heating and far lower than that for solar powered air conditioning. Florida's year-round mild and sunny climate allows swimming during much of the winter, so a properly heated pool is economically attractive.

Finite Element Analysis Of The Femoral Head, Ghandikota Ramamurthy

Theses

Femoral component loosening and Prosthetic stem fractures have renewed interest in conservative alternatives to conventional total hip replacements. One such alternative is the concept of surface replacement. The objective in this study is a finite element analysis of a femoral surface replacement cup with Particular attention given to the interfacial stresses. An axisymmetric model with a grid of two-dimensional isoparametric elements is generated. This study utilizes an adaptive model so as to include the effect of bone remodeling in response to stress. The stiffness is considered to be linearly proportional to the stress in the femoral head and neck. Isotropic …

One-Dimensional Compressible Flow Analysis : Isentropic And Normal Shock, Su-Bo Wong

Theses

A computer program to compute and analyse one-dimensional isentropic compressible flow through variable cross-sectional area with or without a normal shock is developed. The program is written in the "FORTRAN LANGUAGE".

In this work, the area change is the predominant cause of change of flow condition. One of the advantage of this program is set on general uses for isentropic flow. In common practice, the values of the isentropic flow property ratios were tabulated or graphically presented as function of the Mach number with a specified specific heat ratio, K (normally K=1.40 was presented). With todays technology, the most versatile …

Computer Simulation Of Cavity Filling During Injection Molding Process, Sumit Banerjee

Theses

A numerical technique is proposed for the simulation of cavity filling process during injection molding of glass-bead filled polypropylene. The mold cavity is of cylindrical shape. Marker And Cell (MAC) method is utilized for solving the transient flow phenomena, after a mathematical simulation of the flow model is carried out by using the relevant continuity and-momentum equations governing the system. The complexity of the equations involved, results in the simplifying assumption of incompressible and isothermal flow process. A computer program is written on the basis of finite-difference equations developed during the application of MAC method under the prevailing conditions.

The …

A Heat Pump Assisted Shower, Jim Mcgovern

Articles

An energy-efficient water-heating system for a shower is proposed consisting of a low-powered heat pump, a storage tank and an instantaneous heater which, it is felt, may yield a favourable overall cost, in addition to reducing the primary energy consumption. Some preliminary work has been carried out in exploring this concept. It was considered at the outset that an overall coefficient of performance (COP) of 2 should be readily achieved. Values close to this have been realised with the first experimental prototype.

On The Space Shuttle Wing Thermal-Structural Analysis, Kumar Krishna Tamma

Mechanical & Aerospace Engineering Theses & Dissertations

A finite element approach for efficient thermal-structural analysis of structures with thermal protection systems (TPS) is described. The approach is applied to Space Shuttle wing structure configurations subjected to reentry heating. New two and three-dimensional finite elements are developed to model heat transfer in the TPS and supporting structure. A typical TPS/Structural element predicts transient nonlinear temperature variations through the TPS thickness and detailed structural temperatures at the TPS/Structure interface. The accuracy of the TPS/Structure approach in two and three-dimensions is evaluated by comparisons with the conventional approach for various configurations of the wing structure. The results indicate that the …

Bevolute Gear System, Willis M. Carter

Mechanical Engineering Faculty Patents

The present invention relates to a bevolute gearing system which transmits torque between non-intersecting shafts at right angles to each other. The bevolute gear system includes a pinion gear which is flat and in one plane. The pinion gear is designed to include teeth which are shaped in the form of an involute spiral. The bevolute gear system includes a second gear which is also designed to include teeth which are shaped in the form of an involute spiral. The second gear is mounted on a non-intersecting axis at a right angle to the axis of the pinion gear. The …

Test 1470: John Deere 2350 Diesel 16-Speed, Nebraska Tractor Test Lab

Nebraska Tractor Tests

EXPLANATION OF THE TEST PROCEDURE General Tractors are tested at the University of Nebraska according to the Agricultural Tractor Test Code approved by the American Society of Agricultural Engineers and the Society of Automotive Engineers or official Nebraska test procedure. The manufacturer selects the tractor to be tested and certifies that it is a stock model. Each tractor is equipped with the common power consuming accessories such as power steering, power lift pump, generator, etc., if available. Power consuming accessories may be disconnected only when the means for disconnecting can be reached from the operating station. An official representative of …

Test 1477: John Deere 4650 Quadrange Diesel 16-Speed, Nebraska Tractor Test Lab

Nebraska Tractor Tests

EXPLANATION OF THE TEST PROCEDURE General Tractors are tested at the University of Nebraska according to the Agricultural Tractor Test Code approved by the American Society of Agricultural Engineers and the Society of Automotive Engineers or official Nebraska test procedure. The manufacturer selects the tractor to be tested and certifies that it is a stock model. Each tractor is equipped with the common power consuming accessories such as power steering, power lift pump, generator, etc., if available. Power consuming accessories may be disconnected only when the means for disconnecting can be reached from the operating station. An official representative of …

Test 1486: White Farm Equipment-Iseki 2-75 Diesel 16-Speed, Nebraska Tractor Test Lab

Nebraska Tractor Tests

EXPLANATION OF THE TEST PROCEDURE General Tractors are tested at the University of Nebraska according to the Agricultural Tractor Test Code approved by the American Society of Agricultural Engineers and the Society of Automotive Engineers or official Nebraska test procedure. The manufacturer selects the tractor to be tested and certifies that it is a stock model. Each tractor is equipped with the common power consuming accessories such as power steering, power lift pump, generator, etc., if available. Power consuming accessories may be disconnected only when the means for disconnecting can be reached from the operating station. An official representative of …

Test 1494: Ford 3910 (8x4) Diesel 8-Speed, Nebraska Tractor Test Lab

Nebraska Tractor Tests

EXPLANATION OF THE TEST PROCEDURE General Tractors are tested at the University of Nebraska according to the Agricultural Tractor Test Code approved by the American Society of Agricultural Engineers and the Society of Automotive Engineers or official Nebraska test procedure. The manufacturer selects the tractor to be tested and certifies that it is a stock model. Each tractor is equipped with the common power consuming accessories such as power steering, power lift pump, generator, etc., if available. Power consuming accessories may be disconnected only when the means for disconnecting can be reached from the operating station. An official representative of …

Test 1502: Ford 1710 (12x4) Manual Diesel 12-Speed, Nebraska Tractor Test Lab

Nebraska Tractor Tests

EXPLANATION OF THE TEST PROCEDURE General Tractors are tested at the University of Nebraska according to the Agricultural Tractor Test Code approved by the American Society of Agricultural Engineers and the Society of Automotive Engineers or official Nebraska test procedure. The manufacturer selects the tractor to be tested and certifies that it is a stock model. Each tractor is equipped with the common power consuming accessories such as power steering, power lift pump, generator, etc., if available. Power consuming accessories may be disconnected only when the means for disconnecting can be reached from the operating station. An official representative of …

Equation Of State Of Fluid Nh3 From P-V-T And Ultrasound Measurements To 12 Kbar, R. L. Mills, D. H. Lienbenberg, Richard Alan Lesar, Ph. Pruzan

Richard Alan Lesar

A piston-cylinder apparatus was used to measure the pressure, volume, temperature, and ultrasonic velocity (P,V,T,u) of fluid NH3 from 195 to 320 K at pressures up to 12 kbar. Over 1200 sets of P-V-T-u and P-V-T data were fitted to a Tait-type equation of state (EOS) by non-linear least-squares minimization. With quadratic terms in T for the two fitted parameters, the rms deviation is ± 0.2% in V and ± 0.9% in u, which is comparable to the experimental error. The simple Tait EOS is useful over the entire fluid range between the vaporization and melting curves up to T …

An Improved Rotary Singulator, Burford J. Furman, J. M. Henderson

Burford J. Furman

A new operating approach for a previously existing rotary singulator was developed which improves the versatility of the device. This was accomplished by the implementation of a modular mechanism that performed the basic functions of agitation, gating, pocket formation, and exit, all inherent in this type of singulation device.

An Improved Rotary Singulator, Burford J. Furman, J. M. Henderson

Faculty Publications, Mechanical Engineering

A new operating approach for a previously existing rotary singulator was developed which improves the versatility of the device. This was accomplished by the implementation of a modular mechanism that performed the basic functions of agitation, gating, pocket formation, and exit, all inherent in this type of singulation device.

On The Thermodynamics Of Solar Energy Use, Edward A. Fletcher

Journal of the Minnesota Academy of Science

Solar energy, coming from a 5800K heat reservoir, has thermodynamic advantages over fossil fuel combustion which are rarely recognized. This essay discusses the pertinent thermodynamics of chemical conversion processes. It points out the advantage of conducting endothermic processing at high temperatures and the unique character of sunlight as a source of process heat for high-temperature processing.

Utilization And Examination Of A Mass Consistent Wind Flow Model, Joanne M. Carrol

Wind Energy Center Masters Theses Collection

MATHEW, a mass consistent wind flow model is applied to given areas in Princeton and Windsor, Massachusetts for the purpose of determining wind flow fields in those areas and examining the HATIIEW program itself. The MATHEW model which was originated by Sherman at Lawrence Livermore Laboratories to give a three-component time-independent nondivergent wind velocity field. The model has been verified by its creators and is accepted as a valid method for calculating wind fields. A description of the model is given. The analytic foundation of the model is elucidated, the numerical technique is described and the architecture of the MATHEW …

Saving Energy In Rural Maine : Or Who's Doing What On The Farm, Mane Department Of Agriculture

Maine Collection

Saving Energy In Rural Maine : Or Who's Doing What on the Farm

Compiled by Bettina M. Blanchard and Edited by Bill Seekins.

Maine Department of Agriculture, Food and Rural Resources, Division of Resources Development, Augusta, Maine, 1983.

Contents: List of Photographs and Diagrams / Introduction / Projects / 1. Wind / 2. Wood Heat Applications On the Farm / 3. Solar Applications / 4. Manure Handling and Waste Utilization / 5. Energy Efficient Cooling Methods / 6. Energy Saving In Field Operations / 7. Production and Use of Alternative Fuels / 8. Multi-Project Sites / Summary and Conclusions / …

Test 1466: White Farm Equipment-Iseki 2-55 Diesel 16-Speed, Nebraska Tractor Test Lab

Nebraska Tractor Tests

EXPLANATION OF THE TEST PROCEDURE General Tractors are tested at the University of Nebraska according to the Agricultural Tractor Test Code approved by the American Society of Agricultural Engineers and the Society of Automotive Engineers or official Nebraska test procedure. The manufacturer selects the tractor to be tested and certifies that it is a stock model. Each tractor is equipped with the common power consuming accessories such as power steering, power lift pump, generator, etc., if available. Power consuming accessories may be disconnected only when the means for disconnecting can be reached from the operating station. An official representative of …

Test 1467: White Farm Equipment-Iseki 2-65 Diesel 16-Speed, Nebraska Tractor Test Lab

Nebraska Tractor Tests

EXPLANATION OF THE TEST PROCEDURE General Tractors are tested at the University of Nebraska according to the Agricultural Tractor Test Code approved by the American Society of Agricultural Engineers and the Society of Automotive Engineers or official Nebraska test procedure. The manufacturer selects the tractor to be tested and certifies that it is a stock model. Each tractor is equipped with the common power consuming accessories such as power steering, power lift pump, generator, etc., if available. Power consuming accessories may be disconnected only when the means for disconnecting can be reached from the operating station. An official representative of …

Test 1469: John Deere 2150 Diesel 16-Speed, Nebraska Tractor Test Lab

Nebraska Tractor Tests

EXPLANATION OF THE TEST PROCEDURE General Tractors are tested at the University of Nebraska according to the Agricultural Tractor Test Code approved by the American Society of Agricultural Engineers and the Society of Automotive Engineers or official Nebraska test procedure. The manufacturer selects the tractor to be tested and certifies that it is a stock model. Each tractor is equipped with the common power consuming accessories such as power steering, power lift pump, generator, etc., if available. Power consuming accessories may be disconnected only when the means for disconnecting can be reached from the operating station. An official representative of …

Test 1468: White Farm Equipment 2-110 Diesel 18-Speed, Nebraska Tractor Test Lab

Nebraska Tractor Tests

EXPLANATION OF THE TEST PROCEDURE General Tractors are tested at the University of Nebraska according to the Agricultural Tractor Test Code approved by the American Society of Agricultural Engineers and the Society of Automotive Engineers or official Nebraska test procedure. The manufacturer selects the tractor to be tested and certifies that it is a stock model. Each tractor is equipped with the common power consuming accessories such as power steering, power lift pump, generator, etc., if available. Power consuming accessories may be disconnected only when the means for disconnecting can be reached from the operating station. An official representative of …

Test 1471: John Deere 2550 Diesel 16-Speed, Nebraska Tractor Test Lab

Nebraska Tractor Tests

EXPLANATION OF THE TEST PROCEDURE General Tractors are tested at the University of Nebraska according to the Agricultural Tractor Test Code approved by the American Society of Agricultural Engineers and the Society of Automotive Engineers or official Nebraska test procedure. The manufacturer selects the tractor to be tested and certifies that it is a stock model. Each tractor is equipped with the common power consuming accessories such as power steering, power lift pump, generator, etc., if available. Power consuming accessories may be disconnected only when the means for disconnecting can be reached from the operating station. An official representative of …