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1994

Theses/Dissertations

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Articles 1 - 30 of 99

Full-Text Articles in Mechanical Engineering

Development Of An Expert System To Facilitate A Pump Manufacturing/Warehouse Facility, Muhammad Mutahir Ghauri Dec 1994

Development Of An Expert System To Facilitate A Pump Manufacturing/Warehouse Facility, Muhammad Mutahir Ghauri

Theses

The objective of this study is to evaluate the effectiveness of utilizing an expert system technology as it relates to manufacturing. It appears that our industries are still uncertain about this technology. In the first phase of this study, procedure for deployment of this technology is discussed. Secondly a knowledge-based expert system is developed, using a VP-Expert microcomputer shell. The system is made of three modules, inventory module, cost analysis module, and decision making module (for the selection of pumps).

A warehouse was selected for the analysis, which carries the finished product in the form of pumps. The quantities and ...


A Petri-Net Based Methodology For Modeling, Simulation, And Control Of Flexible Manufacturing Systems, Venkatesh Kurapati Dec 1994

A Petri-Net Based Methodology For Modeling, Simulation, And Control Of Flexible Manufacturing Systems, Venkatesh Kurapati

Dissertations

Global competition has made it necessary for manufacturers to introduce such advanced technologies as flexible and agile manufacturing, intelligent automation, and computer-integrated manufacturing. However, the application extent of these technologies varies from industry to industry and has met various degrees of success. One critical barrier leading to successful implementation of advanced manufacturing systems is the ever-increasing complexity in their modeling, analysis, simulation, and control. The purpose of this work is to introduce a set of Petri net-based tools and methods to address a variety of problems associated with the design and implementation of flexible manufacturing systems (FMSs). More specifically, this ...


Robust Approach To Object Recognition Through Fuzzy Clustering And Hough Transform Based Methods, Tianxiong Fu Dec 1994

Robust Approach To Object Recognition Through Fuzzy Clustering And Hough Transform Based Methods, Tianxiong Fu

Dissertations

Object detection from two dimensional intensity images as well as three dimensional range images is considered. The emphasis is on the robust detection of shapes such as cylinders, spheres, cones, and planar surfaces, typically found in mechanical and manufacturing engineering applications. Based on the analyses of different HT methods, a novel method, called the Fast Randomized Hough Transform (FRHT) is proposed. The key idea of FRHT is to divide the original image into multiple regions and apply random sampling method to map data points in the image space into the parameter space or feature space, then obtain the parameters of ...


Simulation Study Of Particle Tracking System, Prashant B. Patel Dec 1994

Simulation Study Of Particle Tracking System, Prashant B. Patel

Theses

A particle tracking system is being developed in the Particle Technology Laboratory of the Mechanical Engineering Department, at NJIT, In this thesis, an attempt is made to understand the effect of various parameters on the errors in the computed position and orientation of the sphere being tracked. Simulation results for a single transmitter assembly as well as a three transmitter assembly with 6, 9 and 17 antennae are presented. The effects of the level of noise in the voltages on the solution for the single transmitter assembly and three transmitter assembly are discussed. The concept of virtual antenna is introduced ...


Use Of Multiple Transmitters For 3-D Non-Intrusive Particle Tracking, Jitesh H. Agrawal Dec 1994

Use Of Multiple Transmitters For 3-D Non-Intrusive Particle Tracking, Jitesh H. Agrawal

Theses

A method for non-intrusive tracking of a particle in 3-dimensional space, based on processing of signals emitted from a transmitter embedded in the particle, is being developed. This method uses a mathematical model, which predicts the induced signal in receivers present in the vicinity of flowing particle, and supporting numerical techniques. Specific application aspects related to improving the accuracy of this method are presented.

The focus here is the development of flexible software capable of processing information coming from multiple transmitters with known distinct spatial orientation. Implementation aspects of modified existing empirical corrections for improving model-reality agreement, and new techniques ...


Investigation Of Velocity Distribution Within High Speed Waterjet, Hong Cao Dec 1994

Investigation Of Velocity Distribution Within High Speed Waterjet, Hong Cao

Theses

The aim of this research was to investigate velocity distribution within the water jet at different conditions of jet formation. The water jet (WJ) velocity was measured by the use of Laser Transit Anemometer (LTA) and statistical technique which improved the accuracy of the velocity determination.

The velocities were measured for different diameters of the sapphire nozzle under different water pressures at different axial stand off distances and radial distances across the jet. The experiments performed in this study enabled us to evaluate the effects and conditions of the water jet on the velocity distribution. The acquired results provide information ...


Viscoelastic Effects On Parallel Flow Stability, Transition To Turbulence, And Turbulent Flow, Michael Garofalo Dec 1994

Viscoelastic Effects On Parallel Flow Stability, Transition To Turbulence, And Turbulent Flow, Michael Garofalo

Theses

The classical two dimensional theory of stability of parallel flow is extended to viscoelastic fluids. How the elasticity of the fluid affects the point of stability and determines the point of transition to turbulence is analyzed. In addition the magnification of disturbances is elucidated. This study is based on a viscoelastic constitutive equation which has been successful in predicting the experimental trends of various unsteady high shear rate laminar flows. A viscoelastic stability equation which is an extension to the Orr-Sommerfeld equation for a Newtonian fluid is derived and solved for a flow between parallel plates superimposed by a two-dimensional ...


Case Study Of Assembly Defects In Manufactured Products, Michael J. Withka Dec 1994

Case Study Of Assembly Defects In Manufactured Products, Michael J. Withka

Theses

Design for Quality Manufacturability (DFQM) is a design tool that empowers engineers to create designs that are easily and effectively transformed into manufactured products. The goal of this methodology is to make designers aware of design characteristics that may lead to product defects during the assembly process. Acknowledging the possibility of these defects will enable the designer to institute design modifications early in the design phase. The benefits realized in this approach are a reduction in the number of defects in the finished product, reduced product cycle times, a reduction in monitoring costs and a reduction in time-to-market.

This thesis ...


Statistical And Finite Element Analysis Of The Effects Of Random Input Parameters On The Mechanical Characteristics Of Sheetmetal Forming Processes Using Quadrature Method, Yu Quan Dec 1994

Statistical And Finite Element Analysis Of The Effects Of Random Input Parameters On The Mechanical Characteristics Of Sheetmetal Forming Processes Using Quadrature Method, Yu Quan

Theses

In this thesis, the computer aided finite element analysis is implemented in the analysis of sheetmetal forming process. To rationalize the experimentation and analysis, the statistical method is introduced to study the variability of sheetmetal deformation process and final shape with respect to the variation of different parameters.

In Chapter 2, the basic characteristics and considerations of deep drawing operation is described with emphasis on the study of geometrical and physical variables of the forming process.

Chapter 3 discussed the three phases which are encountered in the computer aided finite element analysis. As a typical representative of professional finite element ...


Design For Quality Manufacturability Analysis Of Missing/Misplaced Parts And Part Interference, Altaf Yusuf Tamboo Dec 1994

Design For Quality Manufacturability Analysis Of Missing/Misplaced Parts And Part Interference, Altaf Yusuf Tamboo

Theses

Design for Quality Manufacturability (DFQM) is an approach that addresses the issue of quality manufacturability (QM) - the likelihood that defects will occur during manufacture of a product in a standard plant. The DFQM methodology is based on the premise that defects found in assembled products are often influenced by some features of the design and/or assembly process (influencing factors). These influencing factors cause defects in the presence of certain error catalysts.

One of the influencing factors is geometrical features such as shape and symmetry. A classification scheme for part shape and symmetry is developed. This scheme is summarized in ...


An Investigation And Improvement Of Electrorheological (Er) Fluid Technology, Adil F. Dalal Dec 1994

An Investigation And Improvement Of Electrorheological (Er) Fluid Technology, Adil F. Dalal

Master's Theses

The purpose of this research was to investigate and overcome the limitations of Electrorheological (ER) fluids and to introduce this advanced technology at WMU. Electrorheological (ER) Fluids are a special class of fluids, which exhibit a reversible, infinitely variable phase transition from a liquid to a solid/semi-plastic state, in the presence of an electric field.

ER fluids can provide a unique solution to the problems of vibration isolation of systems. The applications are currently limited due to the high voltage requirements, electric power related heating and limited research into wear/abrasive characteristics of ER fluids.

A specially designed and ...


Design Of A Miniature Hydraulic Power Unit, Ryan D. Bruneau Dec 1994

Design Of A Miniature Hydraulic Power Unit, Ryan D. Bruneau

Honors Theses

The need for a newly designed miniature hydraulic power unit has received the attention of Parker-Hannifin Hydraulic Pump/Motor Division. The current power unit is no longer marketable due to the associated costs and its relative size. As a result, a miniature hydraulic power unit has been designed, the culmination to the engineering curriculum at Western Michigan University. In order to increase the overall marketability and to reduce production costs, a transparent plastic reservoir has been incorporated into the design. An appropriate polymer has been chosen to meet the design requirements and finite element analysis has been used to verify ...


The Effects Of Non-Uniform Blade Geometries On Cascade And Turbine Stage Performance, Hiroyuki Maeda Dec 1994

The Effects Of Non-Uniform Blade Geometries On Cascade And Turbine Stage Performance, Hiroyuki Maeda

Master's Theses

It is known that in-service turbomachinery blades do not have uniform shapes. There are small differences due to blade erosion, manufacturing tolerances, or faulty installation. These differences can be in the size, shape, or relative angles of the blade. In an effort to predict losses resulting from changes in blade thickness and/or blade angles, a two-part investigation has been conducted. A two-dimensional unsteady Navier-Stokes flow analysis has been used to perform numerical experiments.

First, simulations were performed for an isolated cascade. One of the two stators was scaled and/or rotated. Results of the numerical simulations show that increasing ...


Improvement Of Waterjet And Abrasive Waterjet Nozzle, Zheng Li Oct 1994

Improvement Of Waterjet And Abrasive Waterjet Nozzle, Zheng Li

Dissertations

This investigation is concerned with the improvement of the nozzle design for water and abrasive water jet machining. The mechanism of formation and characteristics of pure water and abrasive water jets are investigated in order to determine quasi-optimal process conditions.

To improve the pure water jet machining, a pulsed water jet nozzle, which employs the principle of the Helmholtz type resonator, is investigated experimentally and numerically. The experiments show the advantages of this nozzle over the commercial nozzle in cutting and cleaning. A numerical solution of the differential equations of continuity, momentum conservation, turbulent kinetic energy and dissipation for two ...


Local Thermal Stress Factor Of Pipe-Nozzle, David Chihwei Chen Oct 1994

Local Thermal Stress Factor Of Pipe-Nozzle, David Chihwei Chen

Dissertations

A comprehensive study of local thermal stresses at the juncture of pipe-nozzle is presented in this thesis. The thermal loading is assumed to be a linear thermal gradient across the thickness of the pipe and nozzle. Currently, there exists neither experimental nor analytical data that is sufficient for pressure vessel designers to analyze the local thermal stresses at the juncture of pipe-nozzle. In order to provide a comprehensive database to calculate these thermal stresses, the finite element technique is used to provide a series of local thermal stress factor plots as a function of pipe-nozzle geometrical parameters.

For the local ...


Local Stress Factors Of Pipe-Nozzle Under Internal Pressure, Jih-Lian Jack Ha Oct 1994

Local Stress Factors Of Pipe-Nozzle Under Internal Pressure, Jih-Lian Jack Ha

Dissertations

This thesis presents a comprehensive study of local stresses around a pipe-nozzle due to internal pressure. The finite element method (FEM) was employed to provide a numerical solution which will furnish a database for stress analysts to compute local stresses of pipe-nozzle due to internal pressure. The local pressure stresses for both the pipe and the nozzle around the pipe-nozzle juncture are first normalized into pressure stress factors which are then plotted as functions of geometrical parameters, beta, β, (nozzle mean radius / pipe mean radius) and gamma γ, (pipe mean radius / pipe thickness). These local pressure stresses at each point ...


Simulation Of Active Control Of Asymmetric Flows Around Slender Pointed Forebodies, Hazem Sharaf El-Din Oct 1994

Simulation Of Active Control Of Asymmetric Flows Around Slender Pointed Forebodies, Hazem Sharaf El-Din

Mechanical & Aerospace Engineering Theses & Dissertations

At high angles of attack, the flowfield over slender forebodies becomes asymmetric with substantial side force, which may exceed the available control capability. The unsteady compressible Navier-Stokes equations are used to investigate the effectiveness of different active control methods to alleviate and possibly eliminate the flow asymmetry and the subsequent side force. Although the research work focuses on active control methods, a passive control method has been investigated. The implicit, Roe flux-difference splitting, finite volume scheme is used for the numerical computations. Both locally-conical and three-dimensional solutions of the Navier-Stokes equations are obtained.

The asymmetric flow over five-degree semi-apex angle ...


Mechanical Impedance Methods For Vibration Simulation, Jeffrey Allen Gatscher Aug 1994

Mechanical Impedance Methods For Vibration Simulation, Jeffrey Allen Gatscher

Masters Theses

Realistic laboratory simulation of a system's field vibration environment has been of major concern to design and test engineers for many years. The usual practice of basing vibration design and test specifications on an envelope of the equipment base acceleration levels experienced in the field environment has often resulted in excessive levels of overtesting. This results from the large differences between the mechanical impedance of the vehicle structure and that of a fully equalized vibration shaker. Mechanical impedance effects occur naturally in a field environment. Including such effects in a laboratory vibration environment achieves more realistic conditions of similitude ...


Development Of Vibration And Sensitivity Analysis Capability Using The Theory Of Structural Variations, Ting-Yu Rong Jul 1994

Development Of Vibration And Sensitivity Analysis Capability Using The Theory Of Structural Variations, Ting-Yu Rong

Mechanical & Aerospace Engineering Theses & Dissertations

In the author's previous work entitled "General Theorems of Topological Variations of Elastic Structures and the Method of Topological Variation," 1985, some interesting properties of skeletal structures have been discovered. These properties have been described as five theorems and synthesized as a theory, called the theory of structural variations (TSV). Based upon this theory, an innovative analysis tool, called the structural variation method (SVM), has been derived for static analysis of skeletal structures (one-dimensional finite element systems).

The objective of this dissertation research is to extend TSV and SVM from one-dimensional finite element systems to multi-dimensional ones and from ...


Radiative Interactions In Multi-Dimensional Chemically Reacting Flows Using Monte Carlo Simulations, Jiwen Liu Jul 1994

Radiative Interactions In Multi-Dimensional Chemically Reacting Flows Using Monte Carlo Simulations, Jiwen Liu

Mechanical & Aerospace Engineering Theses & Dissertations

The Monte Carlo method (MCM) is applied to analyze radiative heat transfer in nongray gases. The nongray model employed is based on the statistical narrow band model with an exponential-tailed inverse intensity distribution. The amount and transfer of the emitted radiative energy in a finite volume element within a medium are considered in an exact manner. The spectral correlation between transmittances of two different segments of the same path in a medium makes the statistical relationship different from the conventional relationship, which only provides the noncorrelated results for nongray analysis. Two features of the MCM that are different from other ...


The Development Of A Method To Extract High Purity Oxygen From The Martian Atmosphere, Dongchuan Wu Jul 1994

The Development Of A Method To Extract High Purity Oxygen From The Martian Atmosphere, Dongchuan Wu

Mechanical & Aerospace Engineering Theses & Dissertations

A glow-discharge in an ambient Mars atmosphere (total pressure of 5 torr, composed of 95% carbon dioxide) results in the dissociation of carbon dioxide molecules into carbon monoxide and oxygen. If the glow-discharge zone is maintained adjacent and close to a silver membrane, operated at temperatures above 400°C, atomic and molecular oxygen, produced by the glow-discharge, can be separated from the other species by atomic diffusion through the membrane to an ultrahigh vacuum region where the desorbed O2 is then collected. Experiments have been conducted to study the behavior of the glow discharge in both molecular oxygen and ...


Investigation Of Wall Injectors For Supersonic Mixing Enhancement, Yaacov Haimovitch Jul 1994

Investigation Of Wall Injectors For Supersonic Mixing Enhancement, Yaacov Haimovitch

Mechanical & Aerospace Engineering Theses & Dissertations

A comparative study of the interaction between wall mounted swept-ramp injectors and injector nozzle shape has been conducted in a constant area duct to explore techniques to enhance mixing in scramjet combustors. The scramjet combustors are currently being developed for propulsion systems applications on the envisioned hypersonic vehicles. Short combustor residence time, a requirement for fuel injection parallel to the main flow in the combustor, and an overall strong sensitivity of the vehicle performance to the propulsion system motivated the investigation. The swept-ramp injector investigated in this study produces vortex shedding and local separation downstream of the injector's nozzle ...


An Empirical Study Of Just-In-Time And Total Quality Management Principles Implementation In Manufacturing Firms In The U.S., Loknath Sriparavastu Jun 1994

An Empirical Study Of Just-In-Time And Total Quality Management Principles Implementation In Manufacturing Firms In The U.S., Loknath Sriparavastu

Master's Theses

Literature in vogue points out that, in the last decade, American manufacturing companies came a long way in their renewed emphasis on the quality process. Justin- Time (JIT) and Total Quality Management (TQM) are the two magical phrases that are being frequently used in almost all the articles published on quality and productivity. Nevertheless, the literature does not provide any satisfactory explanation as to how JIT and TQM principles are implemented in the manufacturing industries.

This research, through a nationwide empirical survey, analyzed the effects of JIT and TQM strategies implementation. Survey results showed that implementing both JIT and TQM ...


Recent Advances In Engineering Design: Theory And Practice, Andrew J. Moskalik Jun 1994

Recent Advances In Engineering Design: Theory And Practice, Andrew J. Moskalik

Master's Theses

In the last few years, industry and academia have focused greater attention on the area o f engineering design. Manufacturers have implemented new design methods such as concurrent engineering and design for manufacture, and academia has increased research in design-related issues. This paper will attempt to summarize the recent advances, both scholarly and industrial, relating to the field of design. I will examine new methodologies and supporting tools for the design process, both in use and under research. This paper will cover concurrent engineering, design for manufacture, quality methods, design theory research, computer-aided design, expert systems, analysis programs, manufacturing, and ...


An Integrated Approach To Implement Iso 9000 Series Standards To United States Manufacturing Industry, Jatin N. Amin May 1994

An Integrated Approach To Implement Iso 9000 Series Standards To United States Manufacturing Industry, Jatin N. Amin

Theses

Implementation of ISO 9000 series quality system standards to the U.S. manufacturing industry is discussed by developing a generic model for implementation. In recent past, quality became a prime performance issue to formulate strategy to improve market share and profit for U.S. manufacturing industry. Many companies seeks for ISO 9000 registration. Manufacturing industry and other industries as well, are facing numerous problems in implementing ISO 9000 quality system standards. At present, about 400 U.S. companies have gained certification under this standard.

In this work an attempt has been made, to highlight problems which are most likely to ...


Remediation Of Contaminated Sites Using Hot Gas Injection, Sanjay Jayabal May 1994

Remediation Of Contaminated Sites Using Hot Gas Injection, Sanjay Jayabal

Theses

Remediation of contaminated subsurface sites at lower cost and time than currently used technologies are being demonstrated for a systems concept using new technology developed at the Hazardous Substance Management Research Center at New Jersey Institute of Technology. A technique for pneumatic fracture is employed to "open" subsurface passages to enhance vacuum extraction of contaminants. Economical and environmentally sound destruction of these contaminants is then accomplished using catalytic oxidation followed by scrubbing to remove air pollutants. The hot gas from this phase of the process is then injected into the subsurface formation after being used to preheat the fuel/air ...


Kinematic And Kinetic Analysis Of Geneva Mechanisms And Their Applications To Synchronization Of Motion, Bijan Sepahpour May 1994

Kinematic And Kinetic Analysis Of Geneva Mechanisms And Their Applications To Synchronization Of Motion, Bijan Sepahpour

Theses

Geneva mechanisms have been used for generating intermittent motion for use in indexing and packaging operations. Due to their popularity, cost effectiveness and diversified applications in industry, it is desirable to optimize their design.

Optimization techniques and modifications have been developed to provide long life, trouble-free high-speed indexing and intermittent motion while minimizing the undesirable inherent dynamic characteristics of this class of mechanisms.

A general information base of the motion characteristics and types of geneva mechanisms available has been established. Development of the full spectrum of the required equations, generation of the normalized values of critical design parameters along with ...


Particle Dynamics Modeling Of Vibrating Granular Beds, Yidan Lan May 1994

Particle Dynamics Modeling Of Vibrating Granular Beds, Yidan Lan

Dissertations

Particle dynamics modeling is done to study the behavior of granular beds subjected to vibrations imposed by a plane boundary which oscillates sinusoidally about a zero mean speed. Significant differences between the lower and higher shaking acceleration regions are found for the granular temperature and solids fraction depth profiles, which characterize the effectiveness of the boundary in fluidizing the beds. When higher accelerations are applied, the temperature is maximum at the vibrating floor and attenuates through the depth, while the solids fraction profiles exhibit a maximum at some intermediate depth. At lower acceleration values, most of the mass is located ...


Adaptive Nonlinear Control Using Fuzzy Logic And Neural Networks, Shu-Chieh Chang May 1994

Adaptive Nonlinear Control Using Fuzzy Logic And Neural Networks, Shu-Chieh Chang

Dissertations

The problem of adaptive nonlinear control, i.e. the control of nonlinear dynamic systems with unknown parameters, is considered. Current techniques usually assume that either the control system is linearizable or the type of nonlinearity is known. This results in poor control quality for many practical problems. Moreover, the control system design becomes too complex for a practicing engineer. The objective of this thesis is to provide a practical, systematic approach for solving the problem of identification and control of nonlinear systems with unknown parameters, when the explicit linear parametrization is either unknown or impossible.

Fuzzy logic (FL) and neural ...


Automatic Feature Extraction From Conventional Cad Model To Support Feature-Based Design Approach For The Sheet Metal Stamping Industries, Dipak P. Thakar May 1994

Automatic Feature Extraction From Conventional Cad Model To Support Feature-Based Design Approach For The Sheet Metal Stamping Industries, Dipak P. Thakar

Theses

Despite the continuing improvement in computer aided design (CAD) systems and improvements in computer aided manufacturing (CAM), the process planning activity has still not been completely integrated into the CAD/CAM cycle. Particularly in sheet metal stamping industries human interpretation of CAD data is required to extract the geometry and technological information of a component. As a result most CAD systems are used as advanced drafting and drawing management tools by designers. Thus the responsibility for interpreting the design data required for extracting the manufacturing part features still resides with the process planner. Which has increase possibilities of entering errors ...