Engineering Commons^™

Turbomachine Stability And Forced Response Prediction, Leland Bert Clark

Open Access Theses

A mathematical model is developed and utilized to analyze turbomachine cascade flutter and forced response. The flutter boundary, defined as the largest value of reduced frequency at which flutter occurs for a given cascade, was evaluated for single degree of freedom torsional oscillation as well as coupled bending and torsional oscillations. The maximum amplitude of forced response in bending and torsion was also considered. The unsteady aerodynamic lift and moment coefficients were determined from unsteady aerodynamic flow models for subsonic flow, supersonic flow with a subsonic axial component and supersonic axial flow. The effect of changing the Mach number, stagger …

Selection And Implementation Of A Cad/Software System For Navigator Boats, Brian J. Finzel

Honors Capstone Projects and Theses

No abstract provided.

Laser Doppler Velocimetry Research Of The Blowby Gas Characteristics In An Internal Combustion Engine, Mark Kevin Coffill

Masters Theses

The project was designed to measure a reciprocating engine fluid flow (blowby gases past the piston rings) using a laser doppler velocimeter (LDV). Blowby gases were obtained by introducing compressed air into an engine cylinder (piston held at TDC) to simulate engine combustion pressures. Beginning the proposed research included starting an LDV/reciprocating engine laboratory at Western Michigan University and determining the limits of the measurement devices (LDV system in particular).

The limitations which were found in the LDV system only allowed for limited results of in cylinder optical measurements. The results obtained were for cylinder pressures below 0.6 kPa gauge …

Expert System For The Injection Molding Of Engineering Thermoplastics, Tzy-Cherng Jan

Dissertations

Injection molding of engineering thermoplastics is the most widely used manufacturing method in industry. It is a priority to maintain a deviation-free operating environment to ensure high quality, low cost manufacture. An expert system for the injection molding of engineering thermoplastics has been investigated. The system can be used to attenuate the deviations experienced during the injection molding of engineering thermoplastics. The system is coded in C programming language.

The resolution procedures of this system include two stages such as the definition of declarative knowledge and the procedure of corrective actions. In the definition of declarative knowledge, all of the …

Errors In Constant-Velocity Shaft Couplings, Philip M. Remington

Theses

A Multiloop spatial system of rotations is used to represent a shaft coupling, allowing a transmission plane which may deviate from the plane of symmetry to be specified. The plane of transmission, for intersecting input and output shaft axes, is the locus of intersections of screw axes that compose the system. By prescribing the transmission plane outside of the plane of symmetry (commonly called the "homokinetic plane" or "bisecting plane") to pecified orientations, a phase shift between the input and output shaft rotational displacements will he quantified. The rotational phase shift between the input and output shafts can be evaluated …

The Design And Manufacture Of Institutional Trays Using Simultaneous Engineering, Antonio Schmidt

Theses

This study evaluates thermoformed trays as used in the food service industry. The resin used in fabricating trays is a blend of Acrylonitrile Butadiene Styrene (ABS) and Polycarbonate (PC). The life of the trays is presently between 1 to 3 years. The trays are used in correctional facilities and hospitals. The handling of the tray is not abusive. The trays are pulled out of service once they exhibit stress cracking.

To further understand the unpredictable life of the thermoformed trays an understanding of the behavior of the plastics is required and the method of comparing one resin from another, as …

Modeling, Evaluation, And Control Of A Flexible Manufacturing Cell Using Petri Nets, Glenn Arthur Thorniley

Theses

This thesis describes the usefulness of Petri nets in modeling, evaluating, and controlling a Flexible Manufacturing Cell (FMC). The basics of Petri net theory are explained and a specific FMC is examined. First, the FMC is modeled. The purpose of modeling is to facilitate the evaluation and provide a framework on which the control methodologies can be applied. The objective of the evaluation is to determine how the FMC would benefit most by replacing or adding equipment. Several ideas on control are combined to form a useful framework for the designing of the control net. With this framework the control …

Automatic Motion Analysis Of Colliding Spheres, John Vijayakumar Caesar

Theses

Motion analysis is useful to compute linear and angular velocities and acceleration of an object from a sequence of images. This thesis is part of an investigation to compute the translation and rotation velocities needed to determine the collision parameters of two colliding spheres. This involves the tracking of the spheres and feature points on the spheres over a time interval. An experimental setup releases two spheres such that they collide and a high speed imaging system, i.e., Kodak Ektapro 1000 is utilised to record the motion of the spheres. The imaging system is capable of recording at a speed …

Cost Deployment Based On Quality Function Deployment, John Goceljak

Theses

A methodology for Cost Deployment based on Quality Function Deployment (QFD) architecture is developed and explained. Following a comprehensive review of Quality Function Deployment terminology and composition, a house-of-quality is developed, and matrix correlation methodologies are discussed. Current applications are presented to illustrate the scope and adaptability of this quality assurance tool. In addition, an exercise in product design and review is conducted to illustrate a unique approach to cost deployment. Quality Function Deployment issues, including software, consulting, and preferred practices are also presented.

Development Of The Interface Between Cad And Waterjet Nc Systems, Sivayasivan Sambandan

Theses

There has been a continuous need in the present to develop softwares that provide interface between cutting machines and computer control. There involves a number of complex stages from the birth of an algorithm, to develop such software, till the end where it successfully gets tested and implemented. Cutting Path Simulation (CPS) is a partially developed software designed to model 2-d and 3-d objects and down load them to water jet cutting machine. Additional menus were created in the software to perform specific functions. Bugs that existed in the previously done work were removed. Investigation was conducted on the feasibility …

Shop Floor Planning And Control In Integrated Manufacturing Systems, Tahir Mahmood

Theses

The implementation of a shop floor planning and control system is a prerequisite in establishing an effective computer integrated manufacturing system. A shop floor control system integrates management production goals with the capabilities and limitations of the manufacturing plant. Shop floor planning begins with a long term rough cut capacity plan and evolves into near term, capacity requirements and input/output plans. Shop floor control provides a status of in-process operations and a measure of the plants success in executing the plan. Effective use of technology on shop floor increases the efficiency of the manufacturing plant. Simulation is an important tools …

Application Of Desktop Manufacturing System (Sla) For The Manufacturing Of A Centrifugal Pump Impeller Using Cad (I-Deas), Wasimuddin Azam Muhammad Syed

Theses

Desktop Manufacturing (DTM) systems which combine personal computer, laser and other technologies are being used to sculpt objects from computer generated models created on computer aided design (CAD) workstations. As a member of DTM systems, StereoLithography Apparatus (SLA) transforms 3-dimensional designs into a 3-D output. This can substantially reduce the time required to produce a prototype through the process of photopolymerization. The process involves the transfer of a liquid plastic monomer into a solid polymer by exposing it to ultraviolet light.

Although the process looks productive, inefficiencies can occur, if incorrect parameters are selected before its application for a particular …

A Study Of Annular Slurry Jet For Abrasive Waterjet Cutting, Thomas Kuriakose

Theses

The objective of this project is to study the performance of an annualr slurry jet nozzle for abrasive waterjet cutting. This nozzle has been invented by Avraham. Harnoy, Department of Mechanical Engineering, NJIT and presented to the patent committee of NJIT in May 1990. This study includes design and development of prototyes and testing of their performance. Moreover, it includes initial theoretical study of the flow behavior.

The idea is based on the merging of a high velocity pure waterjet with an annular jet of a slurry of water and abrasives at low velocity. The two jets merge outside the …

Design For Productivity Using Gd&T, Srihari G. Acharya

Theses

No abstract provided.

Uses And Applications Of Artificial Intelligence In Manufacturing, Manojkumar H. Desai

Theses

The purpose of the THESIS is to provide engineers and personnels with a overview of the concepts that underline Artificial Intelligence and Expert Systems. Artificial Intelligence is concerned with the developments of theories and techniques required to provide a computational engine with the abilities to perceive, think and act, in an intelligent manner in a complex environment.

Expert system is branch of Artificial Intelligence where the methods of reasoning emulate those of human experts. Artificial Intelligence derives it's power from its ability to represent complex forms of knowledge, some of it common sense, heuristic and symbolic, and the ability to …

Design For Manufacturability And Assembly, Srinivas Mullapudi

Theses

This report presents a study of the various concepts of design for manufacturability and assembly with some case studies, and examples.

The goal of DFM is reduction of parts and simplifying assembly process. A simple faucet has been studied and attempts have been made at re-designing the same using the techniques of design for manufaturability as postulated by Boothroyd, Dewhurst and Henry Stoll.

Computation Of Collision Parameters Of Spheres By Computer Vision, Sumit Sen

Theses

Collision parameter evaluation of rigid spherical particles requires estimation of pre- and post-impact position, velocity and angular velocity vectors of colliding particles. A three dimensional experimental technique is devised where the instantaneous position and orientation of the particles are determined by analyzing frames obtained through high speed video imaging system. Since the image obtained is two dimensional, a mirror setting is designed to capture two orthogonal views of collision in order to estimate motion in depth. The translational velocity vector is determined from the position information extracted through application of available image analysis techniques over two time frames of digitized …

Design Of Nozzle Contours For The Pwt 16-Ft Transonic Wind Tunnel, William Everett Milam

Masters Theses

The nozzle contours of the Tunnel 16T nozzle were designed in the early 1950's and, for the most part, were calculated by hand. In addition, corrections have been made to the contours through the use of an influence coefficient correction technique in an attempt to remove small flow irregularities. This correction technique is not based on aerodynamic theory, and, as a result the corrected contours are not necessarily aerodynamically correct. A second problem stems from the fact that the application of the nozzle corrections results in nozzle contours that do not change in a monotonic manner. There are some jacks …

Laminar And Turbulent Natural Convection Heat Transfer In Trombe Wall Channels, Tony D. T. Chen

Mechanical & Aerospace Engineering Theses & Dissertations

The natural convective heat transfer and air movement in a Trombe wall solar passive system has been studied analytically and numerically. Three Trombe wall channel geometries including the parallel channel with axial inlet and exit, parallel channel with side vents and Trombe wall channel coupled to the room have been considered. Several models representing these Trombe wall geometries have been formulated. For the parallel channel with axial inlet and exit geometry, a momentum-integral method has been used to solve parabolic governing equations for two-dimensional laminar flow. This formulation leads to a second order ordinary differential equation for pressure defect in …

Runge-Kutta Upwind Multigrid Multi-Block Three-Dimensional Thin Layer Navier-Stokes Solver, Frank E. Cannizzaro

Mechanical & Aerospace Engineering Theses & Dissertations

A state-of-the-art computer code has been developed that incorporates a modified Runge-Kutta time integration scheme, Upwind numerical techniques, Multigrid acceleration, and Multi-block capabilities (RUMM). A three-dimensional thin-layer formulation of the Navier-Stokes equations is employed. For turbulent flow cases, the Baldwin-Lomax algebraic turbulence model is used. Two different upwind techniques are available, van Leer's flux-vector splitting and Roe's flux-difference splitting. Full approximation multigrid plus implicit residual and corrector smoothing were implemented to enhance the rate of convergence. Multi-block capabilities were developed to provide geometric flexibility. This feature allows the developed computer code to accommodate any grid topology or grid configuration with …

Investigation Of Waterjet-Workpiece Interaction, Hung-Yuan Li

Dissertations

The objective of this research is to develop new knowledge related to the fundamental physical phenomena of waterjet machining of ductile materials, and to use this knowledge to construct a numerical analysis model. The resulting knowledge will enable enhancement of waterjet cutting efficiency.

Experimental study of fundamental mechanisms and the acquisition of the data detailing micro and macro scale phenomena which occur during the machining process is carried out. It is shown that the material damage mechanism associated with waterjet machining is erosion cavitation which initiates ultrasonic stress wave propagation in the workpiece. Fatigue, an important element in producing material …

Development Of Prediction Technique For The Geometry Of The Abrasive Waterjet Generated Kerf, Yichung Chung

Dissertations

This study is concerned with the development of a practical and accurate technique for off-line determination of the variables characterizing the macro-geometry of the kerf generated in the course of abrasive waterjet (AWJ) machining of ductile materials. The study involved generation and processing of a database relating operational conditions with kerf dimensions. The total number of generated samples exceeded 1500.

A physical model relating the process results with operational conditions was constructed and used for the selection of a statistical technique for analysis of the acquired experimental information. The semiempirical model developed here is based on a simple theoretical model …

Particle Dynamics Modeling Of Boundary Effects In Granular Couette Flow, Hyeong-Jin Kim

Dissertations

This study provides insights in understanding boundary effects on the flow of dry granular materials composed of identical, smooth, inelastic spheres between parallel, bumpy walls in the absence of gravity. The results of this study are useful in providing a basis upon which developing theories can be modified as well as substantiating previous and current experiments. This in turn has a major importance in many industries which are concerned with handling of particulates, such as coal, mineral processing, powder metallurgy, and agriculture.

The particle dynamics or discrete element method is used to model this flow, thereby providing a means of …

Structural Reliability Using Finite Element Method, Che-Chen Liou

Dissertations

During the last decade, structural reliability theory has been treated in a large number of research papers; therefore, from being a subject only well known by a relatively small number of researchers, it has become an important engineering discipline. From the application point of view, many practical applications have been made successfully.

In this dissertation some important fundamental concepts in statistics and in reliability theory are presented. The concept of failure mode can be defined as: A set of failed elements turn a structure into a mechanism. Usually, a structure has many possible failure modes; therefore, it will be necessary …

Local Stress Due To A Radial Loading At Nozzle-Pipe Connection With Different Thickness, Guosheng Lu

Theses

This thesis presents an analysis using the finite element method of the local stress at the nozzle and pipe connection subjected to a radial loading.

In this study, the local stress factor (for membrane and bending stresses) is presented in a series of plots with beta (nozzle radius/pipe radius) values ranging from 0.1 to 1.0 and gamma (pipe radius/wall thickness) values ranging from 10 to 100. The membrane and bending stresses in longitudinal and circumferential directions of the run pipe are computed as a function of the dimensionless parameters, beta and gamma.

For a given external radial loading with different …

Computational Aspects Of A Three Dimensional Non-Intrusive Particle Motion Tracking System, Avadhani S. Ashok

Theses

Development of a technique for non-intrusive particle motion tracking in three dimensions is considered. This technique is based on the principle of magnetic induction. In particular, the determination of the position and onentation of the particle from the information gathered is the pnncipal focus of this thesis. The development of such a system is motivated by the need to understand the flow patterns of granular material. This is of cntical importance in dealing with problems associated with bulk solids flows which occur in almost all industries and in natural geological events. A study of the current diagnostic techniques reveals the …

Design Of A Material Handling System For The Automatic Assembly Of A Shower Head, Irshad Meherally

Theses

The design of a Material Handling System for the Shower Head assembly is proposed. The working principle of complete automation and individual workstation is presented using "I-DEAS" software. Alternative equipments and their usage in the automation of the assembly is also proposed. Custom made fixtures, workcarriers, orienters, magazines, part feeders are designed for the assembly. Analysis of design for assembly in terms of cost and efficiency is performed by generating a Coding System Technique.

Effectiveness Of Additive Correction Multigrid In Numerical Heat Transfer Analysis When Implemented On An Intel Ipsc2, James D. Padgett

Dissertations and Theses

The effectiveness of the Additive Correction Multigrid (ACM) algorithm, a line-byline Tri-diagonal Matrix Algorithm (TDMA), and simple Gauss-Seidel (GS) iteration in numerical heat transfer analysis is investigated on a conventional single processor computer and on a distributed memory parallel computer. The performance of these methods is studied by solving a two-dimensional, steady heat conduction problem. The execution time of ACM on a single processor is proportional to the number of unknowns to the 1.5 power. This is in contrast to the execution time of the TDMA for which the execution time is proportional to the number of unknowns to the …

The Indentation Of Foam Pattern Surfaces By Coordinate Measuring Machine Probes, Sanjay Nenawati

Masters Theses

When coordinate measuring machines are used to measure the complex shapes of foam patterns, the spherical probe tips indent into the soft surface of the pattern. Such indentation represents a measurement error since the indicated dimension will not be the same as the actual dimension. To determine the magnitude of error, the depth of probe tip indentation into PMMA and EPS foam surface (i.e., elastic indentation) was measured as a function of time, applied load, and foam density. The residual indentation after the removal of the load (i.e., plastic indentation) was also studied.

The depth of elastic indentation increased with …

Computational Simulation Of Flow Through Elbows In The Approach Piping Systems To A Headbox, Kasinathan Ramanathan

Masters Theses

The successful operation of the wet end in a paper machine is highly dependent on the approach piping system. Sheet basis weight stability and ease of making wet end adjustments are greatly impaired by improperly designed approach piping systems. Most problems in headbox approach piping occur when the flow splits, combines, and passes through elbows.

Elbows create cross flows, flow separation, and eddies, and play an important role in the uniform and stable delivery of the pulp into the headbox. The effect due to an elbow lasts for a considerable distance downstream of the elbow and is severe when two …