Mechanical Engineering Commons^™

Mechanical Design And Analysis Of A Discrete Variable Transmission System For Transmission-Based Actuators, Sriram Sridharan

Masters Theses

Over the past few years, replacing the hydraulic servo actuators with their electrical counter parts for robotics and remote handling systems has been an active field of research. These systems are of particular interest for tasks involved with the US Department of Energy, where the level of radiation exposure is high and the tasks are highly repetitive. With the hydraulic servo actuators, one is concerned with the issues like the high complexity, cost of the system and the difficulty of maintenance of the system. For high payload operations, the hydraulic systems provide an order of magnitude increase in the power …

Developing A Feedback Control System Using Electromagnets To Increase The Stiffness Of A Circular Saw Blade, Nicholas M. Sullivan

Masters Theses

This document covers the research performed in developing a feedback control system using electromagnets to increase the stiffness of a circular saw blade. A finite element analysis was performed in a model of a saw blade to determine there the electromagnets should be placed relative to the new saw blade. Experimental tests were performed with each component of the system to determine their characteristics. A mathematical model of the complete feedback control system was developed in Simulink. Various tests were performed to determine what parameters could be changed in order to get the desired response out of the system. A …

Instrumentation Development For Assessing The Environment Inside Shipping Containers Of Pancreatic Islets During Air Transportation, Jeffrey Scott Rogers

Masters Theses

This study was conducted to obtain information on the effect of altitude on the internal environment of shipping containers for pancreatic islet cells being transported by commercial aircraft. Previous experience has shown that islet cell counts decrease after the islet cells have been transported by air and received at their point of destination.

A data acquisition system was designed to gather fundamental data for use in the analysis of the effects of the environment inside the containers holding the pancreatic islet cell samples being shipped by either ground or air transport, or both. A test apparatus, which fits the existing …

Investigation Of Compound Micro Cantilever For Imaging And Identifying Micro/Nano Particulates, Ramanathan Narayanan

Masters Theses

Atomic Force Microscopes (AFM) are typically used to image surfaces along with small particulates that may be deposited on the surface. Surface imaging can be made down to the atomic level but usually it is conducted at the nano and micro scales. It is highly desirable to identify the constituency of particulates on the surface and if possible determine the chemical and physical identity of particulates. The objective of the research presented in this thesis is to establish the feasibility of using dual micro cantilevers to determine the physical constituency of nano particles deposited to the micro surface. The goal …

Analysis And Design Of A Gear Shifting Mechanism For Transmission Based Actuators, Kalyana Bhargava Ganti

Masters Theses

The fundamental idea of Transmission Based Actuators (TBA) is to incorporate a multi-speed transmission to spread a servomotor’s torque speed characteristics across a wider output speed range. TBA uses multi-speed transmissions such that heavy, high-torque motors can be traded for high-speed, reduced mass motor-transmission combinations. TBA design consists of a D.C. Brushless motor, discrete gear transmission and a fixed reduction. Of these, the fundamental to the proof of principle of TBA is the design of the discrete gear transmission.

Basically the DVT is a three-speed gearbox consisting of 3 sets of epicyclic gears. Every planetary gear set is a two-degree …

Parameter Study On Topology Optimization Of Constrained Layer Damping Treatments, Rohan Vinay Pai

Masters Theses

This study investigates the optimal topology of a constrained layer damping treatment involving viscoelastic materials under a static load for different boundary conditions in order to maximize the damping loss factor for the first vibrating mode of the base structure. Different parameter studies are carried out for the two boundary conditions and conclusions are drawn based on the loss factor results and the novel topologies that emerge from these optimization results. The novel topologies are then used to interpret shapes that are more reasonable to manufacture. Tremendous improvement in the loss factor (up to 1250%) is obtained by topology optimization …

Modeling Of Corrugated Graphite Foam Heat Exchangers, Timothy Henry Norton Jr.

Masters Theses

A new manufacturing process was recently developed by the Oak Ridge National Laboratory for the production of graphite foam. The high thermal conductivity and heat transfer area of the foam make it desirable for thermal management applications such as compact heat exchangers. The heat transfer capabilities of the foam are especially useful in internal forced convection applications. However, due to the very low permeability of graphite foam, pressure-drop is very high compared to other porous media, and pressuredrop reduction schemes are necessary to ensure its practical application. Pressure-drop reduction can be achieved through the strategic machining of graphite foam into …

Sensor Based Plc Programming For A Discrete Event Control System, Siva Kali Prasad Dasari

Masters Theses

In the manufacturing industry, automation in material handling has increased the overall profitability of the product with an improvement in the quality and productivity of the system. This is primarily due to two reasons. First, automation reduces the total production cycle time, and second, it helps smooth flow of raw materials and finished products to their desired location with little or no human interference. But, such an implementation involves several problems. One significant problem is the location of sensors that perceive the system environment. A correct choice of sensors at precise locations enables the controller to collect the required information …

A Design Study Of A Proposed Four-Seat, Amateur-Built Airplane, D. Andrew Moore

Masters Theses

An airplane configuration suitable for construction by an amateur builder without the need for complex factory fixtures and tooling has been developed. The proposed high-wing configuration is intended to carry a 600 LB payload of up to 4 passengers arranged in 2 rows of side-by-side accommodations at a design cruise speed of 145 kts. It has been shown that the cantilevered wing components of the low-wing, 2-seat Mustang II kit airplane are ideally suited for the proposed airplane when properly matched with strut braced inboard wing panels. The structural implications of optimally sized ailerons on the baseline Mustang II wing …

Design Of An Automobile Passenger Weighing System, Travis Mark Kimmins

Masters Theses

The purpose of this project was to design a low-cost alternative to the current design of a device that weighs the passengers of an automobile in order to determine if the passenger weight is sufficient to deploy an airbag. In addition to designing a system to weigh a passenger, the capability of determining the position of the occupant was also desirable.

Taking into account that seat deflection is a function of weight, linear potentiometers were used to measure deflection. Seven potentiometers were attached to a wire mesh located beneath the foam of the seat. Various weights were applied to locations …

Discrete Event Simulation In Manufacturing Environments: The Waste Isolation Pilot Plant, Benjamin Thomas Burnette

Masters Theses

The purpose of this thesis was to construct a discrete event model of the waste handling activities inside of the Waste Isolation Pilot Plant (WIPP) in order to examine "what-if" scenarios designed to increase the rate at which waste is disposed.

The discrete event modeling software EXTEND was chosen by Sandia National Laboratories (Sandia) because of its ease of use, flexibility, ability to customize, and low cost. Historical and observed data were used to construct, verify, and validate the resulting model. Verification ensures that the model works as programmed, and validation ensures the real world system is truly being modeled …

Scale Model Investigations Of The Effects Of Flow Conditioning Devices, Grady P. Saunders

Masters Theses

A scale model was constructed of a portion of a supersonic wind tunnel to perform experiments on various flow conditioning devices. The various devices researched were: swirl vanes, screens, honeycombs, and various combinations thereof. Each flow conditioning device was analyzed to show its effect on total pressure profiles, static pressure profiles, test section flow angularity, test section turbulence, and acoustic noise. Of most concern are the effects flow conditioning devices have on temporal fluctuation of previously mentioned parameters.

The data from these experiments were used as the basis for selecting a screen-honeycomb combination to be installed in the full-scale tunnel. …

Determination Of The Performance Of A Prototype Turbx Engine, Kurt Erickson

Masters Theses

The purpose of this study was to develop a testing procedure to measure the performance of a prototype TurbX. engine. Dr. Michael A. Wilson invented a new concept internal combustion engine called TurbX. and it is said to have higher efficiency and fuel economy compared to other engines. Theoretically, the TurbX. engine cycle can be ideally represented by the Atkinson thermodynamic cycle with a continuous combustion process.

Oak Ridge National Laboratory and The University of Tennessee, Knoxville joined together to conduct tests to determine the performance of the TurbX. engine. A total of 26 fired test runs were conducted to …

Heat Release Analysis And Modeling For A Common-Rail Diesel Engine, M. Rajkumar

Masters Theses

The main purpose of this study was to perform a heat release analysis in order to formulate a heat-release model for a common-rail diesel engine. The fundamental idea of the model is to describe the observed physical processes with empirical formulas based on the experimental data.

A Fiat 2.4Liter common rail engine was used in the tests. A rotary incremental encoder with 0.1° resolution was coupled to the crankshaft pulley with a special adapter. The engine was operated at a number of different speeds and load conditions. Cylinder pressure data was recorded using a high-speed data acquisition system. The data …

An Experimental Study Of Low Speed Open Cavity Flows, Abraham J. Meganathan

Masters Theses

The experimental work is part of an ongoing study aimed at understanding and controlling of cavity instabilities by passive or active steady or unsteady fluid injection. An experimental setup has been designed to quantitatively visualize the flow-field inside the cavity for varying relative dimensions (L/D ratios of 2.0, 2.67, 3.5 and 4.5, W/D of 3.33) at low subsonic speeds ranging from 55 ft/sec to 214 ft/sec using Particle Image Velocimetry (PIV).

The results showed that PIV could provide instantaneous velocity and other flow field data inside and above the cavity. The quality of data is good and may be used …

One-Dimensional Mean Line Code Technique To Calculate Stage-By-Stage Compressor Characteristics, Sherri Lynette Smith

Masters Theses

Because modem turbine engines have such complex flow fields, extensive testing is required to ensure stability. The testing of these engines and their components is very expensive. To offset testing costs, computer simulations are often used. Several computer simulations have been developed at Arnold Engineering Development Center for this purpose. These codes require stage-by-stage compressor characteristics in order to simulate flow through a compressor.

A technique to calculate compressor characteristics was developed using a mean line code (MLC). This MLC was modified to include loss and deviation correlations from open literature and to account for the conservation of angular momentum …

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. A …

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 …

Modeling Of A Combined Cycle Mhd/Steam Power Plant, Edward H. Kiessling Iii

Masters Theses

The objective of this effort was to develop an improved process model of a prototype MHD/steam central station power plant. This model was designed to perform a first law thermodynamic analysis for steady state plant operation. An existing MHD topping cycle model was modified to provide predictions of mass flows and energy requirements associated with topping cycle equipment for coal processing and oxidant preparation. This topping cycle is characterized by full slag carryover to the heat and seed recovery system. PRESTO II, a program for analyzing the performance of regenerative, superheated steam-turbine cycles, was added to the existing model structure …

A Wear Minimization Design Investigation Of Feedline Splitters, Turning Sections, And Feed Nozzles Of A Pneumatic Conveyed Solids System, Warren R. Gilbert Jr.

Masters Theses

The adverse effects of wear has continually plagued the operation of the TVA 20 MW Atmospheric Fluidized Bed Combustion Pilot Plant. Wear has caused serious problems in all aspects of the pneumatically fed below-bed coal feed system. This has given rise to the development of high wear resistant designs of feedline splitters, turning sections, and feed nozzles.

Wear testing of PVC feedline system components was conducted at The University of Tennessee to determine the wear characteristics of different designs. PVC was chosen for the feedline system component material to accelerate the wear testing results. A series of similar tests were …

Performance Of A Ground-Coupled Heat Pump During A Cooling Season, Steven D. Wix

Masters Theses

A ground-coupled heat pump system was installed in TECH House I at the Tennessee Energy Conservation in Housing site located on the University of Tennessee campus. The performance of the heat pump system was evaluated for the cooling season of 1983. Data on system energy flows, power consumption, house temperatures, soil temperatures and weather conditions were gathered on an hourly basis for the entire cooling season. Weekly coefficients of performance, soil thermal conductivitys, and a seasonal performance factor were calculated from experimental data.

The performance was found to be poor when compared to a conventional air-to-air heat pump system. The …

A General Solution For Wind Tunnel Boundary-Induced Interference In Two-Dimensional Subsonic Flow, Werner Johann Anton Dahm

Masters Theses

A general solution is presented for determination of wind tunnel boundary-induced interference in two-dimensional subsonic flow. The solution requires no a priori knowledge of the model geometry or tunnel wall characteristics, and instead, relates the interference to velocity measurements at a selected control surface within the tunnel. The solutions for the tunnel, free-air and interference fields are obtained using linearized subsonic theory with the Fourier transform technique. An analytical example dealing with the case of the wavy wall in the presence of a generalized tunnel wall boundary condition demonstrates the validity of the solutions in closed form. Numerical examples dealing …

Energy And Cost Analysis Of Commercial Hvac Equipment: Offices And Hospitals, Robert E. Lyman Jr.

Masters Theses

A study was made to determine annual energy use in several typical heating, ventilating, and air conditioning (HVAC) systems for two commercial building types: offices and hospitals. The study was part of a program at Oak Ridge National Laboratory to develop a model to predict energy use in the commercial sector of the United States. This study's objective is to define relationships between energy use and capital cost for commercial HVAC systems.

The NECAP computer program was used to analyze the HVAC systems' energy use. Both pre-embargo and current energy efficient HVAC system designs were modeled with several energy conservation …

Energy Conservation And Economic Analysis Of Residential Refrigerators, Robert A. Hoskins

Masters Theses

A detailed computer model is developed to calculate energy flows and electricity use for residential refrigerators. Model equations are derived from application of the first law of thermodynamics, analysis of manufacturers' literature, and related studies. The model is used to evaluate the energy (and associated initial cost) impacts of alternative designs to reduce refrigerator energy use.

Model results show that 56% of the total heat gain in a typical 0.45 m³ (16 ft³) top-freezer refrigerator is due to conduction through cabinet walls and doors. The remaining 44% is from door openings, heaters, fans, food, gasket area infiltration, …

Transient Response Of Linear Elastic Structures Determined By The Matrix Exponential Method, William Christopher Terrill Stoddart

Masters Theses

This investigation was undertaken to develop a numerical solution for the transient response of linear, elastic structures based on the matrix exponential solution for first order, linear, constant coefficient differential equations. The investigation was prompted by the need for an economical technique that can be used to analyze multidegree of freedom systems exemplified by piping and structural components associated with nuclear power plants.

A mathematical model characterizing the behavior of linear, elastic structures was developed by using state variables of displacement and velocity. The structure consists of beam elements of uniformly distributed mass, weightless springs, and rigid masses. The stiffness …

An Experimental Study Of The Viscoseal Bearing, Chandrakant Khumaji Shah

Masters Theses

The experimental data obtained from two groove geometries of the viscoseal bearing were analyzed to study the bearing characteristics and the sealing performance. The experimental bearing characteristics were compared with the Dubois and Ocvirk Short-bearing Approximation. The sealing performance analysis of the bearing included (1) the determination of the sealing coefficient which was compared with the Stair and Hale method of theoretical prediction and (2) the effect of the bearing eccentricity ratio on the sealing coefficient, which was compared with the Vohr and Chow method of theoretical prediction.

The results of the study indicated that, at constant load and speed, …

The Design And Construction Of A Visco Seal Test Facility, Charles Franklin Bowman

Masters Theses

No abstract provided.

The Analysis Of Cantilever Plates With Concentrated Loads, Constant Roberts Marks

Masters Theses

(From the Introduction)

The problem of a cantilever plate or slab with variable, discontinuous, concentrated, or eccentric loading occurs frequently in engineering design. Examples are substructure walls, piers, projecting floor slabs, and gear teeth. The solution of most of these problems can be made to depend on the analysis of the plate in question loaded with one or more concentrated loads. Such analyses are available for only a few cases of loading, and no practical method is available to the designer for making any kind of a reasonably accurate stress analysis for many cases he may encounter.

In …