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Full-Text Articles in Engineering

Nebraska Summary: S120 Ford Versatile 946, Nebraska Tractor Test Lab Jan 1991

Nebraska Summary: S120 Ford Versatile 946, 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 …

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A Stratified Air Model For Simulation Of Attic Thermal Performance, Florida Solar Energy Center, Danny Parker Jan 1991

A Stratified Air Model For Simulation Of Attic Thermal Performance, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

An improved computer simulation model for attics has been developed. The model accounts for detailed radiation, buoyancy and wind driven air flows and thermal stratification within the attic airspace. Through comparison with measured data, the paper examines the relative importance of the various modeling parameters and assumptions upon simulation accuracy. Stratification of the attic air was found to be a critical modeling characteristic which is typically ignored in building energy simulations. Both model and measurement results shows that air stratification increases significantly when low-emittance surfaces are included.

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Impact On Laminated Composite Materials, Serge Abrate Jan 1991

Impact On Laminated Composite Materials, Serge Abrate

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Laminated composite materials are used extensively in aerospace and other applications. With their high specific modulus, high specific strength, and the capability of being tailored for a specific application, these materials offer definite advantages compared to more traditional materials. However, their behavior under impact is a concern, since impacts do occur during manufacture, normal operations, or maintenance. The situation is critical for impacts which induce significant internal damage, undetectable by visual inspection, that cause large drops in the strength and stability of the structure. Impact dynamics, including the motion of both the impactor and the target and the force developed …

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Matrix Cracking In Laminated Composites: A Review, Serge Abrate Jan 1991

Matrix Cracking In Laminated Composites: A Review, Serge Abrate

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This article presents an overview of the problem of matrix cracking in laminated composite materials. The parameters governing the onset and accumulation of internal damage under several types of loadings are reviewed. The analysis of laminates with matrix cracks can be performed using a shear-lag model, variational, elasticity, finite element or finite difference approaches. Prediction of further cracking is based on either a fracture mechanics approach or a probabilistic failure strength theory. Continuum damage mechanics are used by some investigators to model the behavior of the cracked laminate. Recent developments in this area are summarized here, and suggestions for future …

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Hierarchical Neurocontroller Architecture For Intelligent Robotic Manipulation, Xavier J. R. Avula, Luis C. Rabelo Jan 1991

Hierarchical Neurocontroller Architecture For Intelligent Robotic Manipulation, Xavier J. R. Avula, Luis C. Rabelo

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A hierarchical neurocontroller architecture consisting of two artificial neural network systems for the manipulation of a robotic arm is presented. The higher-level neural system participates in the delineation of the robot arm workspace and coordinates transformation and the motion decision-making process. The lower one provides the correct sequence of control actions. The capabilities, including speed, adaptability, and computational efficiency, of the developed architecture are illustrated by an example.

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Petri Net Modeling Of A Flexible Assembly Station For Printed Circuit Boards, M. Zhou, Ming-Chuan Leu Jan 1991

Petri Net Modeling Of A Flexible Assembly Station For Printed Circuit Boards, M. Zhou, Ming-Chuan Leu

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Petri net modeling approaches are presented for a flexible workstation for automatic assembly of printed circuit boards. In order to improve the productivity of such a system, the building of mathematical models is a crucial step. Concentrating on the operational aspects, the authors construct ordinary and temporal Petri net models for the AT&T FWS-200 physical flexible workstation. Three outcomes follow from such models. First, designers can have a better understanding of concurrency, synchronization, mutual exclusion, and sequential relations involved in the system control from the graphical representations of Petri nets. Second, the performance analysis of system operations under different settings …

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Test 1651: Case International 9250 Diesel And Steiger 9250 Diesel 12-Speeds, Nebraska Tractor Test Lab Jan 1991

Test 1651: Case International 9250 Diesel And Steiger 9250 Diesel 12-Speeds, 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 …

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Test 1643: Ford 3430 (8x2) Diesel 8-Speed, Nebraska Tractor Test Lab Jan 1991

Test 1643: Ford 3430 (8x2) 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 …

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Test 1650: Case International 9240 Diesel And Steiger 9240 Diesel 12-Speeds, Nebraska Tractor Test Lab Jan 1991

Test 1650: Case International 9240 Diesel And Steiger 9240 Diesel 12-Speeds, 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 …

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Test 1646: Ford 8630 Powershift Diesel 18-Speed, Nebraska Tractor Test Lab Jan 1991

Test 1646: Ford 8630 Powershift 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 …

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Nebraska Summary: S103 Ford 3930 8x8, Nebraska Tractor Test Lab Jan 1991

Nebraska Summary: S103 Ford 3930 8x8, 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 …

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Second Coefficient Of Viscosity In Air, Robert L. Ash, Allan J. Zuckerwar, Zhonquan Zheng Jan 1991

Second Coefficient Of Viscosity In Air, Robert L. Ash, Allan J. Zuckerwar, Zhonquan Zheng

Mechanical & Aerospace Engineering Faculty Publications

Acoustic attenuation measurements in air were analyzed in order to estimate the second coefficient of viscosity. Data over a temperature range of 11 C to 50 C and at relative humidities between 6 percent and 91 percent were used. This analysis showed that the second coefficient of viscosity varied between 1900 and 20,000 times larger than the dynamic or first coefficient of viscosity over the temperature and humidity range of the data. In addition, the data showed that the molecular relaxation effects, which are responsible for the magnitude of the second coefficient of viscosity, place severe limits on the use …

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Test 1338/2: Hurlimann 6135 Vdt Diesel, Nebraska Tractor Test Lab Jan 1991

Test 1338/2: Hurlimann 6135 Vdt Diesel, Nebraska Tractor Test Lab

Nebraska Tractor Tests

No abstract provided.

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Nebraska Summary: S100 John Deere 3055, Nebraska Tractor Test Lab Jan 1991

Nebraska Summary: S100 John Deere 3055, 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 …

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Test 1652: Case International 9260 Diesel And Steiger 9260 Diesel 12-Speeds, Nebraska Tractor Test Lab Jan 1991

Test 1652: Case International 9260 Diesel And Steiger 9260 Diesel 12-Speeds, 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 …

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Test 1654: Caterpiller Challenger 75 And 75c Diesel 10-Speed, Nebraska Tractor Test Lab Jan 1991

Test 1654: Caterpiller Challenger 75 And 75c Diesel 10-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 …

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Test 1644: Ford 3930 (8x2) Diesel 8-Speed, Nebraska Tractor Test Lab Jan 1991

Test 1644: Ford 3930 (8x2) 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 …

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Test 1645: Ford 4630 (8x2) Diesel 8-Speed, Nebraska Tractor Test Lab Jan 1991

Test 1645: Ford 4630 (8x2) 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 …

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Test 1647: Ford 8730 Powershift Diesel 18-Speed, Nebraska Tractor Test Lab Jan 1991

Test 1647: Ford 8730 Powershift 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 …

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Test 1649: Case International 9230 And Steiger 9230 (12-Speeds) Diesels, Nebraska Tractor Test Lab Jan 1991

Test 1649: Case International 9230 And Steiger 9230 (12-Speeds) Diesels, 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 …

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Intelligent Control Of A Robotic Arm Using Hierarchical Neural Network Systems, Xavier J. R. Avula, Luis C. Rabelo Jan 1991

Intelligent Control Of A Robotic Arm Using Hierarchical Neural Network Systems, Xavier J. R. Avula, Luis C. Rabelo

Chemical and Biochemical Engineering Faculty Research & Creative Works

Two artificial neural network systems are considered in a hierarchical fashion to plan the trajectory and control of a robotic arm. At the higher level of the hierarchy the neural system consists of four networks: a restricted Coulomb energy network to delineate the robot arm workspace; two standard backpropagation (BP) networks for coordinates transformation; and a fourth network which also uses BP and participates in the trajectory planning by cooperating with other knowledge sources. The control emulation process which is developed using a second neural system at a lower hierarchical level provides the correct sequence of control actions. An example …

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Analysis Of Shear Banding In Plane Strain Compression Of A Bimetallic Thermally Softening Viscoplastic Body Containing An Elliptical Void, Z. G. Zhu, R. C. Batra Jan 1991

Analysis Of Shear Banding In Plane Strain Compression Of A Bimetallic Thermally Softening Viscoplastic Body Containing An Elliptical Void, Z. G. Zhu, R. C. Batra

Mechanical and Aerospace Engineering Faculty Research & Creative Works

We study plane strain thermomechanical deformations of a prismatic viscoplastic body of square cross-section and deformed at a nominal strain-rate of 5000 s-1. The body has two thin layers placed symmetrically about the horizontal centroidal axis and an elliptical void at the center. The major axis of the void coincides with the vertical centroidal axis and also with the direction of loading. The layer material differs from that of the body in only the value of the yield stress in a quasistatic simple compression test. The yield stress for the layer material is taken to be either one-fifth or five …

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Dynamic Adiabatic Shear Band Development In A Bimetallic Body Containing A Void, R. C. Batra, Z. G. Zhu Jan 1991

Dynamic Adiabatic Shear Band Development In A Bimetallic Body Containing A Void, R. C. Batra, Z. G. Zhu

Mechanical and Aerospace Engineering Faculty Research & Creative Works

We study the problem of the initiation and subsequent growth of a shear band in a thermally softening viscoplaslic prismatic body of square cross-section and containing two symmetrically placed thin layers of a different viscoplastic material and an elliptical void at the center. The yield stress of the material of the thin layer in a quasistatic simple compression test is taken to be either five times or one-fifth that of the matrix material. The body is deformed in plane strain compression at a nominal strain rate of 5.000 s '. These deformations are assumed to be symmetrical about the centroidal …

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Narrow-Winged Seeder Points Reduce Water Erosion And Maintain Crop Yields, Kevin Bligh Jan 1991

Narrow-Winged Seeder Points Reduce Water Erosion And Maintain Crop Yields, Kevin Bligh

Journal of the Department of Agriculture, Western Australia, Series 4

Sowing crops without loosening the topsoil by tillage reduces water erosion. It can increase infiltration of rainfall into loamy soils, thereby reducing runoff and increasing potential crop yields. Crop yields were maintained after I1 seasons of seeding an Avon Valley loam near Beverley with minimum and no-tillage seeding operations. Infiltration increased significantly from 80 per cent of the 1983 growing-season rainfall under the traditional three tillage operations, to 87per cent under a single tillage operation using a combine seed drill. Infiltration increased further to 96 per cent under a no-tillage system using a triple^lisc drill. At Gnowangerup, 80 per cent …

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Methods Of Measuring The Solubility And Viscosity Of Lubricating Oil/Refrigerant Mixtures At High Discharge Pressures And Temperatures, Nolan Van Gaalen Jan 1991

Methods Of Measuring The Solubility And Viscosity Of Lubricating Oil/Refrigerant Mixtures At High Discharge Pressures And Temperatures, Nolan Van Gaalen

Faculty Work Comprehensive List

The design and construction of a test facility and methodology for measuring the solubility and viscosity of lubricating oil/refrigerant mixtures at high pressures and temperatures are described. An auxiliary charging system, developed to provide precisely measured quantities of oil and refrigerant to the test facility, is also presented. The test facility was developed under the sponsorship and supervision of ASHRAE which funded this research project (RP-580);The solubility, viscosity and density of mixtures of R-22 and of R-502 with commonly used 150 SUS lubricants have been measured by using this facility. Specifically, results for liquid mixtures of 10% to 40% refrigerant …

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A Computer Simulation Model Of Waterhyacinth And Weevil Interactions, Kunter S. Akbay, F. G. Howell, J. W. Wooten Jan 1991

A Computer Simulation Model Of Waterhyacinth And Weevil Interactions, Kunter S. Akbay, F. G. Howell, J. W. Wooten

Mechanical Engineering Faculty Research and Publications

A personal computer simulation model termed "INSECT" has been developed to evaluate biological control of waterhyacinth (Eichhornia crassipes (Mart.) Solms.) by two species of weevil (Neochetina eichhorniae Warner, and N. bruchi Hustache). The model results were compared with the data from three different locations. For each data set, the simulated plant biomass, adult and larva populations were plotted against the 95% confidence intervals of the actual field observations. In many cases, the simulation results were within the 95% confidence intervals, and especially during the growing season, they indicated trends similar to those seen in the field data. However, there were …

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Using Optimization And Simulation Techniques To Estimate Initial Weevil Populations, Kunter S. Akbay Jan 1991

Using Optimization And Simulation Techniques To Estimate Initial Weevil Populations, Kunter S. Akbay

Mechanical Engineering Faculty Research and Publications

In this paper, a mathematical programming and simulation method is used to estimate the number of weevils (Neochetina bruchi Hustache, and N. eichhorniae Warner) necessary to initialize the INSECT model which simulates the biological control of waterhyacinth by the weevils. The objective is to estimate the initial input values for the adult population so that the sum of the absolute differences between the observed and the simulated numbers of weevils is minimized. In general, the simulated values using the initial values obtained from the mathematical programming problem were within the 95% confidence intervals of the actual field observations. Also, in …

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Toward The Optimization Of Cell Operator Productivity In Computer Integrated Manufacturing, David Leonard Gobeski Jan 1991

Toward The Optimization Of Cell Operator Productivity In Computer Integrated Manufacturing, David Leonard Gobeski

Dissertations and Theses @ UNI

Computer integrated manufacturing (CIM) has been seen as the answer to maintaining the lead in American productivity. The cell operator was seen as being critical to the success of CIM. The design of the operator's job was seen as very important. As manufacturing engineers design cell jobs, including the roles and tasks, with the operators, it was believed important for the engineer to know what motivated the cell operator. However, past studies of supervisors and their subordinates have shown that supervisors are unable to predict the importance of the elements of job enrichment of the subordinates. It was questioned whether …

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Micromechanics Of Granular Materials And Its Relation To Wave Velocity, Tarun K. Agarwal Jan 1991

Micromechanics Of Granular Materials And Its Relation To Wave Velocity, Tarun K. Agarwal

Civil & Environmental Engineering Theses & Dissertations

The macro characters of the granular materials depend upon micromechanical parameters such as the void ratio, particle shape, contact force distribution, and initial state of the fabric of the assembly. Since it is difficult to evaluate these internal parameters from laboratory experiments, a macro measure is desired which depends directly on these internal parameters. One such measure has been shown to be dynamic shear modulus but it was incomplete in predicting directional changes in the internal parameters. Therefore, it is hypothesized here that the complete elastic moduli matrix will have more direct information about the internal parameters, especially the dynamic …

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Numerical Modeling Of Flame Lift-Off Phenomenon And Calculation Of Thermal Loads On A Methane Fuel Injector With Complex Geometry, Taj O. Mohieldin Jan 1991

Numerical Modeling Of Flame Lift-Off Phenomenon And Calculation Of Thermal Loads On A Methane Fuel Injector With Complex Geometry, Taj O. Mohieldin

Mechanical & Aerospace Engineering Theses & Dissertations

A numerical study has been conducted to analyze a fuel injector with three in-line cylinder geometry that has been adopted as a model for investigating the combustion phenomenon in the 8-Foot High Temperature Tunnel (HTT) combustor at the NASA Langley Research Center. The primary objective here is to analyze the flame lift-off phenomenon in the three cylinder fuel injector geometry in two-dimensions. The fluid mechanics model used in the analysis includes time-averaged Navier-Stokes equations that are employed in conjunction with a two-equation k-$\epsilon$ model for predicting the effects of turbulence. Calculations were performed with three chemistry models, namely fast chemistry, …

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