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Mechanical Engineering Commons

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1991

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Articles 1 - 30 of 38

Full-Text Articles in Mechanical Engineering

Unsteady Flow In Vertical, Converging Tubes, Hamid Johari, William W. Durgin Dec 1991

Unsteady Flow In Vertical, Converging Tubes, Hamid Johari, William W. Durgin

Office of the Provost and Vice President of Academic Affairs Scholarship

The discharge of liquids from vertical tubes with various contraction geometries was studied via the unsteady Bernoulli equation. The temporal variations of the exit velocity and fluid level in the tube were found from the numerical integration of nonlinear differential equations. Sudden, quadratic, and exponential contraction geometries were considered. For inlet to exit area ratios greater than two, the flow initially accelerates to a maximum speed and then it decelerates for the geometries studied. The exponential contraction has the shortest discharge time. The solutions also reveal that the largest possible velocity and the shortest discharge time are achieved in a ...


Ultrasonic Nde Of Thick Composites, R. Bruce Thompson, Donald O. Thompson, David K. Holger, David K. Hsu, M. S. Hughes, Emmanuel P. Papadakis, Yu-Min Tsai, Loren W. Zachary Dec 1991

Ultrasonic Nde Of Thick Composites, R. Bruce Thompson, Donald O. Thompson, David K. Holger, David K. Hsu, M. S. Hughes, Emmanuel P. Papadakis, Yu-Min Tsai, Loren W. Zachary

Aerospace Engineering Conference Papers, Presentations and Posters

A series of ultrasonic techniques being developed for the characterization of thick composites are described. Techniques for the in-situ measurements of elastic constants on thick-walled cylinders based on the times of a variety of ultrasonic modes of propagation are first presented, followed by discussion of the determination of the porosity from measurements of the frequency dependence of the attenuation. Two techniques for imaging delamination are then discussed. The first involves inferring size from plots of reflected signal amplitude versus lateral position of the transducer with a model for beam propagation in anisotropic media used to deconvolve the effects of the ...


Test 1656: Ford 5640 (16x4) Diesel 16-Speed, Tractor Museum Nov 1991

Test 1656: Ford 5640 (16x4) Diesel 16-Speed, Tractor Museum

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 ...


An Approach To Simultaneous Control Of Trajectory And Interaction Forces In Dual-Arm Configurations, Xiaoping Yun, Vijay R. Kumar Oct 1991

An Approach To Simultaneous Control Of Trajectory And Interaction Forces In Dual-Arm Configurations, Xiaoping Yun, Vijay R. Kumar

Departmental Papers (MEAM)

Multiple arm systems, multifingered grippers, and walking vehicles all have two common features. In each case, more than one actively coordinated articulation interacts with a passive object, thus forming one or more closed chains. For example, when two arms grasp an object simultaneously, the arms together with the object and the ground (base) form a closed chain. This induces kinematic and dynamic constraints and the resulting equations of motion are extremely nonlinear and coupled. Furthermore, the number of actuators exceeds the kinematic mobility of the chain in a typical case, which results in an underdetermined system of equations. An approach ...


Chemical And Evaporative Behaviors Of Synthetic Liquid Nuclear Waste, Donna Macgrath Cline Aug 1991

Chemical And Evaporative Behaviors Of Synthetic Liquid Nuclear Waste, Donna Macgrath Cline

FIU Electronic Theses and Dissertations

In the 1960's the Department of Energy at Oak Ridge National Laboratory designed eight 50,000 gallon storage tanks for the liquid nuclear waste. Each tank was designed with its own ventilation system to purge radiolytic hydrogen and oxygen from the tank. This design induced water removal and necessitated the additional requirement of entraining radioactivity from the exiting system by the use of demisters and HEPA filters.

Up until the 1980's this was a sufficient method, via the hydrofracture process, of disposing the liquid nuclear waste. However since then, this method has been terminated and the tanks are ...


Active Control Of Convection, Jonathan Singer, Haim H. Bau Aug 1991

Active Control Of Convection, Jonathan Singer, Haim H. Bau

Departmental Papers (MEAM)

It is demonstrated theoretically that active (feedback) control can be used to alter the characteristics of thermal convection in a toroidal, vertical loop heated from below and cooled from above. As the temperature difference between the heated and cooled sections of the loop increases,t he flow in the uncontrolled loop changes from no motion to steady; time independent motion to temporally oscillatory, chaotic motion. With the use of a feedback controller effecting small perturbations in the boundary conditions, one can maintain the no-motion state at significantly higher temperature differences than the critical one corresponding to the onset of convection ...


Breakdown Of A Wire-To-Plane Discharge: Transient Effects, Milind A. Jog, Ira M. Cohen, Portonovo S. Ayyaswamy Aug 1991

Breakdown Of A Wire-To-Plane Discharge: Transient Effects, Milind A. Jog, Ira M. Cohen, Portonovo S. Ayyaswamy

Departmental Papers (MEAM)

A wire-to-plane discharge during the early phases of breakdown has been studied. The discharge has been modeled in a prolate spheroidal coordinate system with the wire shape taken as a hyperboloid of revolution. Four simultaneous coupled, time-dependent, nonlinear partial differential equations describe the electrical discharge. These are the conservation equations for ion and electron densities, the energy equation for electron temperature, and Poisson’s equation for the self-consistent electric field. By solving this formulation subject to appropriate initial and boundary conditions, charged particle densities and temperature variations have been obtained as the ionization progresses in the discharge. The results show ...


Antique Farm Machinery And Equipment Commission July, 1991, Tractor Museum Jul 1991

Antique Farm Machinery And Equipment Commission July, 1991, Tractor Museum

Museum Planning and Development Documents

No abstract provided.


Tardiness Heuristic For Scheduling Flexible Manufacturing Systems, Ali S. Kiran, Sema E. Alptekin, A. Celal Kaplan Jul 1991

Tardiness Heuristic For Scheduling Flexible Manufacturing Systems, Ali S. Kiran, Sema E. Alptekin, A. Celal Kaplan

Industrial and Manufacturing Engineering

This paper evaluates the tardiness performance of a sampling-based adaptive heuristic in a dynamic manufacturing environment. A test bed, following a real world manufacturing system, has been developed. The proposed algorithm has been implemented in this simulated environment. After fine tuning the algorithm, it has been tested in various shop conditions. The results of these simulation studies are summarized.


Tractor Museum Committee Establishment 1991, Tractor Museum Jun 1991

Tractor Museum Committee Establishment 1991, Tractor Museum

Museum Planning and Development Documents

No abstract provided.


The Use Of A High Level Cfd Code In Engineering Education, J.E.S. Venart, P. Lemieux, A.C.M. Sousa, D. Tatchell Jun 1991

The Use Of A High Level Cfd Code In Engineering Education, J.E.S. Venart, P. Lemieux, A.C.M. Sousa, D. Tatchell

Mechanical Engineering

An advanced multipurpose Computational Fluid Dynamics (CFD) code, FloSYS, developed for use in a CAD/CAE environment has been utilized in undergraduate and graduate courses in heat transfer. Problems are introduced at an introductory level in: -steady 2- and 3-dimensional conduction, -transient 1-, 2-, and 3-dimensional conduction, -free convective cavity flow with conjugate heat transfer, and -turbulent flows with heat transfer. More sophisticated problems, related to the use of porous media concepts for modelling heat exchangers, and compartment fire modelling are introduced at a more senior level. After one year's experimental use, the CFD code is being recommended for ...


Controlling A Chaotic System, Jonathan Singer, Y-Z Wang, Haim H. Bau Mar 1991

Controlling A Chaotic System, Jonathan Singer, Y-Z Wang, Haim H. Bau

Departmental Papers (MEAM)

Using both experimental and theoretical results, this Letter describes how low-energy, feedback control signals can be successfully utilized to suppress (laminarize) chaotic flow in a thermal convection loop.


The Effect Of An Adjacent Viscous Fluid On The Transmission Of Torsional Stress Waves In A Submerged Waveguide, Jin O. Kim, Yuzhou Wang, Haim H. Bau Mar 1991

The Effect Of An Adjacent Viscous Fluid On The Transmission Of Torsional Stress Waves In A Submerged Waveguide, Jin O. Kim, Yuzhou Wang, Haim H. Bau

Departmental Papers (MEAM)

The effects of an adjacent fluid's viscosity and density on the characteristics of torsional stress waves transmitted in a waveguide with a circular cross section are studied theoretically and experimentally. Expressions for the torsional waves speed, dispersion relations, and attenuation are obtained as functions of the adjacent fluid's viscosity and density. The theoretical results are compared with experimental observations. It is demonstrated that a devices similar to the one described herein can be used as a rugged, real-time, on-lines sensor for measuring the viscosity of a fluid with a known density. Such a sensor can measure the viscosity ...


The Evolution Of The Wpi Advanced Space Design Program - An Evolving Program Of Technical And Social Analysis Using The Nasa Space Shuttle For Engineering Education, Fred J. Looft, Robert C. Labonte, William W. Durgin Feb 1991

The Evolution Of The Wpi Advanced Space Design Program - An Evolving Program Of Technical And Social Analysis Using The Nasa Space Shuttle For Engineering Education, Fred J. Looft, Robert C. Labonte, William W. Durgin

Office of the Provost and Vice President of Academic Affairs Scholarship

In December of 1982, Worcester Polytechnic Institute, with the cooperation and support of the MITRE Corporation, initiated a primarily undergraduate educational program to develop experiments to be flown onboard a NASA Space Shuttle. Christened the MITRE WPI Space Shuttle Program, it sponsored the development of five educationally meritorious experiments over a period of four years. Although the experiments were ready to fly in early 1986, the Challenger disaster delayed their flight until the Spring of 1991. The delay notwithstanding, the benefits of the first program were sufficient to justify the development of a second set of experiments. More comprehensive in ...


Knowledge-Based Support For Management Of Concurrent, Multidisciplinary Design, Raymond E. Levitt, Yan Jin, Clive L. Dym Jan 1991

Knowledge-Based Support For Management Of Concurrent, Multidisciplinary Design, Raymond E. Levitt, Yan Jin, Clive L. Dym

All HMC Faculty Publications and Research

Artificial intelligence (AI) applications to design have tended to focus on modeling and automating aspects of single discipline design tasks. Relatively little attention has thus far been devoted to representing the kinds of design 'metaknowledge' needed to manage the important interface issues that arise in concurrent design, that is, multidisciplinary design decision-making. This paper provides a view of the process and management of concurrent design and evaluates the potential of two AI approaches—blackboard architectures and co-operative distributed problem-solving (CDPS)—to model and support the concurrent design of complex artifacts. A discussion of the process of multidisciplinary design highlights elements ...


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

Test 1643: Ford 3430 (8x2) Diesel 8-Speed, Tractor Museum

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 1642: Ford 3230 (8x2) Diesel 8-Speed, Tractor Museum Jan 1991

Test 1642: Ford 3230 (8x2) Diesel 8-Speed, Tractor Museum

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 1644: Ford 3930 (8x2) Diesel 8-Speed, Tractor Museum Jan 1991

Test 1644: Ford 3930 (8x2) Diesel 8-Speed, Tractor Museum

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 1646: Ford 8630 Powershift Diesel 18-Speed, Tractor Museum Jan 1991

Test 1646: Ford 8630 Powershift Diesel 18-Speed, Tractor Museum

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 1645: Ford 4630 (8x2) Diesel 8-Speed, Tractor Museum Jan 1991

Test 1645: Ford 4630 (8x2) Diesel 8-Speed, Tractor Museum

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 1647: Ford 8730 Powershift Diesel 18-Speed, Tractor Museum Jan 1991

Test 1647: Ford 8730 Powershift Diesel 18-Speed, Tractor Museum

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 1648: Ford 8830 Powershift Diesel 18-Speed, Tractor Museum Jan 1991

Test 1648: Ford 8830 Powershift Diesel 18-Speed, Tractor Museum

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

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

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 1650: Case International 9240 Diesel And Steiger 9240 Diesel 12-Speeds, Tractor Museum Jan 1991

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

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 1651: Case International 9250 Diesel And Steiger 9250 Diesel 12-Speeds, Tractor Museum Jan 1991

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

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 1652: Case International 9260 Diesel And Steiger 9260 Diesel 12-Speeds, Tractor Museum Jan 1991

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

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 1654: Caterpiller Challenger 75 And 75c Diesel 10-Speed, Tractor Museum Jan 1991

Test 1654: Caterpiller Challenger 75 And 75c Diesel 10-Speed, Tractor Museum

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 1553: Caterpiller Challenger 65b And 65c Diesel 10-Speed, Tractor Museum Jan 1991

Test 1553: Caterpiller Challenger 65b And 65c Diesel 10-Speed, Tractor Museum

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 1655: Belarus 572, 505, 525 And 570 Diesel 18-Speeds, Tractor Museum Jan 1991

Test 1655: Belarus 572, 505, 525 And 570 Diesel 18-Speeds, Tractor Museum

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 1338/2: Hurlimann 6135 Vdt Diesel Jan 1991

Test 1338/2: Hurlimann 6135 Vdt Diesel

Nebraska Tractor Tests

No abstract provided.