Engineering Commons^™

Development Of An Advisory System For Indoor Radon Mitigation, Patricia Hiromi Byrne

Dissertations and Theses

A prototype hybrid knowledge-based advisory system for indoor radon mitigation has been developed to assist Pacific Northwest mitigators in the selection and design of mitigation systems for existing homes. The advisory system employs a heuristic inferencing strategy to determine which mitigation techniques are applicable, and applies procedural methods to perform the fan selection and cost estimation for particular techniques. The rule base has been developed employing knowledge in existing publications on radon mitigation. Additional knowledge has been provided by field experts. The benefits of such an advisory system include uniform record-keeping and consistent computations for the user, and verification of …

Design Optimization Of Laminated Fiber Composites, Ramarao G. Prasad

Theses

Laminated Fiber Composites are finding a wide range of applications in structural design especially for light weight structures that have stringent stiffness and strength requirements Finding an efficient composite structural design that meets the requirements of a certain application can be achieved not only by sizing the cross-sectional areas and member thicknesses but also by global or local tailoring of the material properties through selective use of orientation, number and stacking sequence of the laminae that make up the composite laminate.

The work presented here treats the design optimization problem involving minimum weight design of fiber composite laminates subject to …

Automation Of Part Inspection In A Coordinate Measuring Machine, Madhu N. Kanoor

Theses

Some of the drawbacks in inspecting a part using a Direct Computer Controlled Coordinate Measuring Machine are that a programmer has to generate a part program for the inspection process, and such programs have to be generated for each part to be inspected. These programs will be restricted to a kind of CMM, thus preventing the portability of the program t o other kinds of CMM.

If a part program can be generated off line after a part has been designed in a CAD system. an operator can inspect the part without any prior knowledge of the esoteric CMM programming …

Development Of Technology For Glass Shaping By The Use Of Abrasive Water-Jet, Li-Yuan Shih

Theses

This study is to investigate the effects of AWJ properties on the results of glass machining and to develop a practical procedure for prediction of these results of abrasive waterjet (AWJ) machining. The use of glass in engineering and Abrasive Waterjet Cutting Technology are introduced. A practical technique to prevent defects and to improve the quality of the glass surface is suggested. A earlier parameter introduced, Exergy Distribution Density (EDD), is used in order to characterize the cutting conditions.

It was found that besides of EDD the results of machining are affected by the particles' destruction in the course of …

Ole Miss Engineer 1991

Ole Miss Engineer

No abstract provided.

Experimental Study Of Transition In A Supersonic Free Shear Layer, Rudolph A. King

Mechanical & Aerospace Engineering Theses & Dissertations

The transition behavior of a free shear layer above a cavity with high and low levels of freestream acoustic disturbances has been investigated at Mach 3.5 in the Supersonic Low-Disturbance Pilot Tunnel located at NASA Langley Research Center. Schlieren photography, mean pitot pressure data, and hot-wire surveys were used to detect transition locations. The transition Reynolds numbers obtained were between Re_Tr = 3.6 x 10⁵ and 5.3 x 10⁵ in good agreement with conventional ("noisy") wind tunnel results. The study indicated that the effects of a decrease in freestream noise on Re_Tr were minimal but, as …

Finite Element Frequency Domain Solution Of Nonlinear Panel Flutter With Temperature Effects And Fatigue Life Analysis, David Yongxiang Xue

Mechanical & Aerospace Engineering Theses & Dissertations

A frequency domain solution method for nonlinear panel flutter with thermal effects using a consistent finite element formulation has been developed. The von Karman nonlinear strain-displacement relation is used to account for large deflections, the quasi-steady first-order piston theory is employed for aerodynamic loading and the quasi-steady thermal stress theory is applied for the thermal stresses with a given change of the temperature distribution, ΔΤ (x, y, z). The equation of motion under a combined thermal-aerodynamic loading can be mathematically separated into two equations and then solved in sequence: (1) thermal-aerodynamic postbuckling and (2) limit-cycle oscillation. The Newton-Raphson iteration technique …

Nontraditional Machining Techniques With Emphasis On Waterjet Milling, Shiv K. Kunapuli

Theses

The rapid growth of harder and difficult-to-machine materials over the past two decades necessitates the development of compatible nonconventional machining techniques, as detailed in this work, with special emphasis on one of the most recent machining method, the abrasive-waterjet technique(AWJ).

The feasibility of using AWJ for milling on glass is investigated. Due to the large number of parameters involved in the AWJ technique, and the multitude of machining requirements, optimization of performance is the focus. These parameters include waterjet pressure, particle size, abrasive flow rate, traverse rate and number of passes.

Surface topography is found to be a function of …

Implementation Of An Integrated High Energy Beam Workcell, Varadaraj Souda

Theses

This study is an effort to advance the technology of machining by High energy beams. Investigation of the Waterjet, Plasma and the Oxyfuel beams was carried out to explore novel machining techniques. The study was focussed on three major objectives.

One of the major objectives was to set up an Integrated beam workcell consisting of the three beams. A hydroabrasive waterjet workcell was modified to install the three cutting tools to be along the same line of traverse. An integrated beam consisting of the thermal and the waterjet beams was produced because of this arrangement. The feasibility of using the …

A Three-Dimensional Finite Element Stress Analysis Of Interface Conditions In Porous Coated Hip Prosthesis, Siu-For Yau

Theses

A three-dimensional finite element model of a collar-type hip stem and both the cortical and cancellous bones is used to investigate the stress distributions on an implanted femoral stem, adjacent bone, and specifically at the bone/implant interface for various amounts of porous coating and different stem materials. The finite element model consists of 909 nodes comprising 536 linear eight-node solid brick elements and 176 two-node interface elements. The finite element analysis code employed is SUPERTAB from SDRC. The interface elements consist of coincident-node spring elements and gap elements which model the rigidly bonded and loose interfaces respectively. Local coordinate systems …

Computer Aided Process Planning System For Generating Alternative Process Plans, Rao T. Gali

Masters Theses

Computer Aided Process Planning (CAPP) has a key role in Computer Integrated Manufacturing (CIM) as an interface between design and manufacturing. Current CAPP systems treat process planning as a static function, and always generate the same machine and process combinations. Thus, these CAPP systems are inadequate for advanced manufacturing facilities such as Flexible Manufacturing Systems (FMS). This thesis presents research conducted for the design and development of a CAPP system called Alternative Computer Aided Process Planning (A-CAPP) which generates alternative process plans by interacting with production planning and machine loading functions to satisfy system capacity constraints.

A-CAPP is a variant …

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

Lester F. Larsen Tractor Museum: Planning and Development Documents

No abstract provided.

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.

Integrated System Identification And Adaptive State Estimation For Control Of Flexible Space Structures, Chung-Wen Chen

Mechanical & Aerospace Engineering Theses & Dissertations

Accurate state information is crucial for control of flexible space structures in which the state feedback strategy is used. The performance of a state estimator relies on accurate knowledge about both the system and its disturbances, which are represented by system model and noise covariances respectively. For flexible space structures, due to their great flexibility, obtaining good models from ground testing is not possible. In addition, the characteristics of the systems in operation may vary due to temperature gradient, reorientation, and deterioration of material, etc. Moreover, the disturbances during operation are usually not known. Therefore, adaptive methods for system identification …

Simulation And Measurement Of The Radiant Field Produced By Quartz Heating Systems, Travis Lee Turner

Mechanical & Aerospace Engineering Theses & Dissertations

A method is developed for predicting the radiant heat flux distribution produced by tungsten-filament tubular quartz heating systems with reflectors. The method is an application of Monte Carlo simulation, which takes the form of a ray tracing or random walk scheme. The method is applied to four systems of increasing complexity including; a single unreflected lamp, a single lamp with a flat reflector, a single lamp with a parabolic reflector, and up to six lamps in a six-lamp contoured reflector heating unit. The general methodology of the Monte Carlo method is discussed and applied to the simulation of thermal radiation. …

Investigation Of Radiative Interactions In Supersonic Chemically Reacting Channel Flows, Almuttil M. Thomas

Mechanical & Aerospace Engineering Theses & Dissertations

Analyses and numerical procedures are presented to investigate the radiative interactions of absorbing emitting species in chemically reacting supersonic flow in various ducts. The two-dimensional time dependent Navier-Stokes equations in conjunction with radiative flux equation are used to investigate supersonic flows undergoing finite rate chemical reaction in a hydrogen air system. The specific problem considered is the flow of premixed radiating gas between parallel plates. Specific attention is directed in investigating the radiative contribution of H2O, OH and NO under realistic physical and flow conditions. Results are presented for the radiative flux obtained for different gases and for various combination …

Dynamic Test/Analysis Correlation Using Reduced Analytical Models, Paul E. Mcgowan

Mechanical & Aerospace Engineering Theses & Dissertations

Test/analysis correlation is an important aspect of the verification of analysis models which are used to predict on-orbit response characteristics of large space structures. This thesis summarizes the study of using reduced analysis models for performing dynamic test/analysis correlation. The reduced test-analysis model (TAM) has the same number of degrees-of-freedom (DOF) as the number of test measurements. This allows the direct comparison of modal parameters between ground vibration test results and finite element model (FEM) analysis results. The TAM can also be used for pre-test analysis and to aid in the post-test mathematical model updating process.

Herein, four methods for …

Conceptual Design Of Dual Cam Mechanisms Using Graph Theory, Raymond Lee Mcclendon

Mechanical & Aerospace Engineering Theses & Dissertations

This paper presents the theory of graphs and how they can be applied to the conceptual design of dual-cam mechanisms. The graph theory was used to validate the results of previous authors (Hain and Pryor). Several applications of dual cam mechanisms are reviewed.

Algorithms using a process of bit mapping were used to developed all possible non-isomorphic graphs for various classes of mechanisms. A classification method was developed using common occurring substructures found in the graphs. This classification scheme was used for conversion of graphs into schematics. Once the results of Hain were verified, the investigation turned to mechanisms with …

An Experimental And Analytical Investigation Of Wing Flutter On A Trial Rotor V/Stol Aircraft, David L. Soistmann

Mechanical & Aerospace Engineering Theses & Dissertations

A wind tunnel model based on a trail rotor vehicle concept was tested for wing flutter in the subsonic flow regime. The wind tunnel model was flutter tested in the forward flight mode only. From this test it was determined that this conceptual vehicle may be susceptible to wing flutter. However, the flutter encountered was not catastrophic but was of the limited amplitude type. The trailing rotor blades were found to have a positive aerodynamic damping effect on flutter. The flutter mechanism for each flutter point was due to a coupling of the first wing bending and first wing torsion …

On Shock Capturing For Liquid And Gas Media, Tze Jang Chen

Mathematics & Statistics Theses & Dissertations

The numerical investigation of shock phenomena in gas or liquid media where a specifying relation for internal energy is absent poses special problems. Classically, for gas dynamics the usual procedure is to employ a splitting scheme to remove the source terms from the Euler equations, then up-wind biased shock capturing algorithms are built around the Riemann problem for the system which remains. However, in the case where the Euler equations are formulated in the term of total enthalpy, a technical difficulty associated with equation splitting forces a pressure time derivative to be treated as a source term. This makes it …

Tractor Museum Committee Establishment 1991, Tractor Museum

Lester F. Larsen Tractor 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

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 use in …

Energy Use In Attached And Detached Residential Developments: Survey Results, Florida Solar Energy Center, Robin Vieira

FSEC Energy Research Center®

The relationship between land use, density, dwelling types and energy use in Florida has never been comprehensively examined. Few people consider both energy used in housing and energy used for local transportation. Florida state officials and some land planners have called for compact urban growth to reduce traffic congestion and travel distances. However, energy is rarely mentioned in these arguments. Local governments are trying to respond to the state's concern for compact growth. Developers, on the other hand, are concerned with meeting the local regulations. Unfortunately, energy use is seldom considered and there is little data available to guide decision …

Investigation Of Air Distribution System Leakage And Its Impacts In Central Florida Homes, Florida Solar Energy Center, James B. Cummings

FSEC Energy Research Center®

Testing for air leakage in air distribution systems was done in 160 central Florida homes. Tracer gas tests found that infiltration rates were three times greater when the air handler was operating that when it was off, indicating that there are large leaks in the air distribution system. Infiltration averaged 0.91 air changes per hour (ach) with the air handler (AH) operating continuously and 0.28 ach with the AH off. Return leaks were measured by tracer gas and found to average 10.7% of AH total flow. House airtightness, in 99 of these homes, determined by blower door testing, averaged 12.7 …

Investigation Of Stagnation Flow Heat Transfer For A Heated Horizontal Round Plate, Ching-Hua Wei

Dissertations

The heat transfer characteristics in stagnation flow are investigated through three cases in this study. The first is forced convection by an array of air jets; the second is free convection of a downward-facing heated round plate; the third is free convection of an upward-facing heated round plate.

The first case is investigated by systematic experiments which examine the heat transfer characteristics mainly by five air jets impinging normally to a flat plate, with varying nozzle diameters, and Reynolds numbers, at different distances between the nozzles and the plate. The empirical formulas of heat transfer around the stagnation point and …

Interfacing Plasticating Extruders With Personal Computers For Data Acquisition, Information Analysis And Retrieval Purposes, Gautamkumar Y. Shah

Theses

The current manufacturing industries are influenced more and more by computers and automation. Two of the major areas of computer uses are data acquisition and interfacing, both lead towards automation.

The intent of this thesis is to focus on the area of interfacing personal computers with plasticating extruders for information retrieval and storage. The requirements for software and hardware are discussed. Analysis of the stored information can be used to improve the quality of the final product. Implications of the stored parameters on the final product are also discussed. A sample program to store and retrieve the important parameters is …

Design For Assembly : Re-Design Of An Electrical Switch For The Ease Of Automatic Assembly, Achyuta Reddy Pannala

Theses

A design for assembly (DFA) method is used to analyze the existing design of parts of an electrical switch, and to reduce and re-design them, for the ease of automatic assembly. The procedure for the selection of suitable and economical assembly method is presented based on the Boothroyd & Dewhurst methods. Analysis of the initial design for manual assembly and the re-design for automatic assembly are presented. An algorithmic approach for simplified generation of all mechanical assembly sequences and selecting the good assembly sequences is presented with graphical representations. A work station needed for the automatic assembly is developed, which …

Effect Of Shrinkage On The Design And Manufacture Of Plastic Parts In Injection Molding Using Cad/Cam Techniques, Deepak M. Shastri

Theses

Computer aided design software in injection molding has revolutionized injection molding in the design and manufacturing processes. Computer Aided Engineering can be applied to injection molding to increase the process efficiency, reduce part costs, and produce accurate parts in less time. The mold designer has many software programs to choose from to produce satisfactory mold designs from part geometries, and a correct selection can produce profitable results. A study of the need for and the scope of computers in injection molding is performed to evaluate the suitability of a CAE package by considering the value added to the parts using …

A Process For Implementing Cim In A Small Manufacturing Facility, Tushar R. Desai

Theses

This work is dedicated to small manufacturing enterprises seeking to explore Computer Integrated Manufacturing (CIM) technology, which is the recent trend in the manufacturing world. The main theme of this thesis is to improve productivity, product quality and reliability, and to reduce costs by integrating various discipline in small manufacturing environment, using computer technology.

To achieve this goal, a hypothetical small manufacturing company was chosen as a subject. The typical functional and organizational structures were analyzed and possible problem areas were highlighted. The problems relating to manufacturing process were studied in detail, and possible solutions were proposed to computerize the …

Automated Computer Drafting Of Precision Tooling For Drawing Operation, Basani Venkateswarlu

Theses

Based on customer requirements of components, design engineers create the necessary tooling using CAD to produce the exact part desired by the customer. A software package using CARL is developed to help the design engineer to create the drawings of Pinch off Punch and Pinch off for both rectangular/square and round punches. A variety of hole patterns for the punches are automatically created through the software, along with a possibility of selecting one of the standard patterns automatically for a drawing. The drawings are created such that the dimensions and the notes are automatically generated with the input of the …