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University of Tennessee, Knoxville

Masters Theses

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Articles 1 - 30 of 143

Full-Text Articles in Mechanical Engineering

Design Of A Robotic Instrument Manipulator For Endoscopic Deployment, Ryan Ponten Aug 2017

Design Of A Robotic Instrument Manipulator For Endoscopic Deployment, Ryan Ponten

Masters Theses

This thesis describes the initial design process for an application of continuum robotics to endoscopic surgical procedures, specifically dissection of the colon. We first introduce the long-term vision for a benchtop dual-instrument endoscopic system with intuitive haptic controllers and then narrow our focus to the design and testing of the instrument manipulator itself, which must be actuated through the long, winding channel of a standard colonoscope.

Based on design requirements for a target procedure, we analyze simulations of two types of continuum robots using recently established kinematic and mechanic modeling approaches: the concentric-tube robot (CTR) and the concentric agonist-antagonist robot ...


Nanoscale Investigations Of Thermal And Momentum Transport In Graphene – Water Systems, Drew Champion Marable May 2017

Nanoscale Investigations Of Thermal And Momentum Transport In Graphene – Water Systems, Drew Champion Marable

Masters Theses

Demand for miniaturized electronic devices has given rise to new challenges in thermal management. Integration with graphene, a two-dimensional (2D) material with excellent thermal properties, allows for further reduced sizes and combats thermal management issues within novel devices. Moreover, due to its wide availability and adequate thermal properties, liquid water is commonly used within traditional thermal systems to enhance cooling performance; as such, water is expected to yield similar performance in smaller-scale applications. However, at reduced sizes descending to the nanoscale realm, system behaviors deviate from traditional macroscale-based theory as interfacial effects become amplified. Employing insight provided by molecular dynamics ...


Development, Analysis, And Optimization Of A Swirl-Promoting Mean Flow Solution For Solid Rocket Motors, Andrew Steven Fist Dec 2016

Development, Analysis, And Optimization Of A Swirl-Promoting Mean Flow Solution For Solid Rocket Motors, Andrew Steven Fist

Masters Theses

This work demonstrates and analyses a new flow candidate for describing the internal gaseous motion in simulated rocket motors. The fundamental features of this solution include the conservation of key system properties also incorporated in the classic Taylor-Culick (TC) system (i.e. inviscid, axisymmetric, steady and rotational properties), while allowing for the development of a swirling velocity component. The work compares the new solution to the development and formulation of the classic TC system, ultimately identifying that both the new and classic solutions are special cases of the Bragg-Hawthorne equation. Following this development, the text then explores the development of ...


Effects Of Ultrasonic Transducers On Heat Transfer In Packed Particle Beds, David Patrick Moseley Dec 2016

Effects Of Ultrasonic Transducers On Heat Transfer In Packed Particle Beds, David Patrick Moseley

Masters Theses

The objective of this study was to determine the effects of ultrasonic transducers on heat transfer in a packed particle bed heat exchanger. Although substantial research has been devoted to ultrasound, and the associated improvements in heat transfer, data regarding the effects on packed particle beds is non-existent. This is of particular interest given the potential to improve heat transfer in a wide variety of packed particle bed systems. A 42.9% increase in the heat transfer rate was demonstrated as the result of improved fluid convection throughout the packed particle bed. Secondary effects, including acoustic cavitation, acoustic streaming and ...


Tracking Of Human Joints Using Twist And Exponential Map, Xiaodong Yang Dec 2016

Tracking Of Human Joints Using Twist And Exponential Map, Xiaodong Yang

Masters Theses

Motion tracking system in the home-based environment exhibits attractive advantages for stroke patients. Current methods suffer from incapability of accurately tracking movements with high degree of freedoms. Besides hardly meeting the predefined position during inertial sensor mounting also affects system's performance.

To tackle these challenges, a motion tracking system using twist and exponential map technology is developed in this paper. Firstly, a kinematic model for trunk and upper extremity is designed. Based on this model, twist and exponential map method which updates frames in their initial coordinates instead of transforming coordinates from one frame to another presents high efficiency ...


Dynamic Monitoring And Life Prediction Of Internal Strain-Gage Balances, David Leon Yoder Dec 2016

Dynamic Monitoring And Life Prediction Of Internal Strain-Gage Balances, David Leon Yoder

Masters Theses

Wind tunnel test customers continue to push the limits by producing air vehicle designs that produce high aerodynamic loads at the desired test conditions. These loads are a combination of steady aerodynamic, unsteady aerodynamic, and inertial forces. A methodology to monitor the health of a wind tunnel strain-gage balance has been developed. The objective of this methodology is to define the stress limits of the balance and monitor these limits so the balance can be safely tested without failure of the balance. A balance failure could result in costly damage to the wind tunnel model, support system, and the wind ...


Developing Predictive Models For Upper Extremity Post–Stroke Motion Quality Estimation Using Decision Trees And Bagging Forest, Sarvenaz Chaeibakhsh Aug 2016

Developing Predictive Models For Upper Extremity Post–Stroke Motion Quality Estimation Using Decision Trees And Bagging Forest, Sarvenaz Chaeibakhsh

Masters Theses

Stroke is one of the leading causes of long–term disability. Approximately twothirds of stroke survivors require long-term rehabilitation, which suggests the importance of understanding the post-stroke recovery process during his activities of daily living. This problem is formulated as quantifying and estimating the poststroke movement quality in real world settings. To address this need, we have developed an approach that quantifies physical activities and can evaluate the performance quality. Wearable accelerometer and gyroscope are used to measure the upper extremity motions and to develop a mathematical framework to objectively relates sensors’ data to clinical performance indices. In this article ...


Laser Diagnostics Of C2h4 And Ch4 From N-Butane Pyrolysis, Liu Su Aug 2016

Laser Diagnostics Of C2h4 And Ch4 From N-Butane Pyrolysis, Liu Su

Masters Theses

Combustion of fossil fuels remains the dominant source of energy which enables us sustain thrive in this planet. Meanwhile, the negative effects of burning fossil fuels, however, are devastating our climate and environment. Eliminating those negative effects while attaining energy supply from fossil fuels becomes urgent and prominent. It is, nevertheless, impossible without a thorough understanding of the combustion process.

Experimental approach remains one of the dominating approaches to study combustion despite the growing interest in numerical approach. The development of workstations and massive supercomputers is providing the computation ability that one has never imaged. Nevertheless, it still appears difficult ...


Tribological Testing And Analysis Of Ionic Liquids As Candidate Anti-Wear Additives For Next-Generation Engine Lubricants, William Charles Barnhill May 2016

Tribological Testing And Analysis Of Ionic Liquids As Candidate Anti-Wear Additives For Next-Generation Engine Lubricants, William Charles Barnhill

Masters Theses

In this work, fourteen ionic liquids (ILs) were assayed as potential next-generation engine oil additives. After screening for corrosion, thermal stability and oil solubility, candidate additives were subjected to friction and wear tests in both boundary and mixed regime lubrication. While each IL demonstrated friction and wear reduction compared to base oil without any additives, oil miscible ILs tetraoctylphosphonium bis 2-ethylhexyl phosphate ([P8888][DEHP]) and trioctylammonium bis 2-ethylhexylphosphate ([N888H][DEHP]) were the best performers in bench tests with a XX% and XX% improvement in wear over the base oil respectively. Each of these ILs excellent solubility and superior performance was ...


Measurement Of Water Ice Accumulation On A First Surface Gold Mirror Under Cryogenic, High-Vacuum Conditions, William Hayden Stevens May 2016

Measurement Of Water Ice Accumulation On A First Surface Gold Mirror Under Cryogenic, High-Vacuum Conditions, William Hayden Stevens

Masters Theses

Spacecraft optical components must be tested in vacuum chambers in order to achieve “space-like” conditions on earth. To simulate the low temperatures experienced in space, optical components are often cryogenically cooled in the vacuum chamber. Outgassing of contaminants, such as water molecules, from the metal walls of the vacuum chamber occur under high vacuum conditions. These free water molecules accumulate and freeze on the cryogenic optical surfaces, which affects performance and reflectivity.

A multiple beam interference set-up was used to measure the accumulation of a water ice film on a first surface gold mirror under cryogenic, high vacuum-conditions. Zeolite molecular ...


Improving Ventricular Catheter Design Through Computational Fluid Dynamics, Sofy Hefets Weisenberg May 2016

Improving Ventricular Catheter Design Through Computational Fluid Dynamics, Sofy Hefets Weisenberg

Masters Theses

Cerebrospinal fluid (CSF) shunts are fully implantable medical devices that are used to treat patients suffering from conditions characterized by elevated intracranial pressure, such as hydrocephalus. In cases of shunt failure or malfunction, patients are often required to endure one or more revision surgeries to replace all or part of the shunt. One of the primary causes of CSF shunt failure is obstruction of the ventricular catheter, a component of the shunt system implanted directly into the brain's ventricular system. This work aims to improve the design of ventricular catheters in order to reduce the incidence of catheter obstruction ...


Improved Modeling Of Atmospheric Entry For Meteors With Nose Radii Between 5cm And 10m, Jakob Dale Brisby May 2016

Improved Modeling Of Atmospheric Entry For Meteors With Nose Radii Between 5cm And 10m, Jakob Dale Brisby

Masters Theses

Atmospheric entry studies typically look closely at the peak heating rate that a body encounters during its trajectory. This is an extremely important phenomenon to study because it allows engineers to determine if a trajectory is possible with given materials and craft design specifications. It also allows designers to choose what type of method will be used for mitigating the enormous heat fluxes during entry. In general, it is accepted that during the super-sonic flight regime the body will continue to be heated and an ablative heat shield often is used to deal with these heating processes. The theory outlined ...


Jet Flow Validation Of Positron Emission Particle Tracking Utilizing High Speed Video, Seth Thomas Langford May 2016

Jet Flow Validation Of Positron Emission Particle Tracking Utilizing High Speed Video, Seth Thomas Langford

Masters Theses

Positron Emission Particle Tracking (PEPT) generates 4D Lagrangian particle trajectories and is used to evaluate flow in granular media and complex geometries where optical interrogation methods are not possible. A Multi-Particle PEPT (Multi-PEPT) approach was developed by the University of Tennessee Thermal Fluids Group capable of finding and tracking many particles simultaneously to extend the utility of the PEPT method. This thesis compares 4,014 trajectories generated using the Multi-PEPT method with 3,055 trajectories generated from High Speed Video (HSV) data. All trajectories are acquired in an acrylic test section with water flow using resin beads. The flow geometry ...


Extending The Lean Limit Of Methane-Air Mixtures By Oxygen, Nitrogen And Carbon Dioxide Injection In The Gap Of The Spark Plug’S Electrodes, Artem Alexandrov Temerev Dec 2015

Extending The Lean Limit Of Methane-Air Mixtures By Oxygen, Nitrogen And Carbon Dioxide Injection In The Gap Of The Spark Plug’S Electrodes, Artem Alexandrov Temerev

Masters Theses

An experimental investigation is carried out to investigate the feasibility of extending the lean limit for methane–air mixtures by injecting oxygen and other gases such as nitrogen and carbon dioxide in the area between spark plug electrodes. Additionally, the effect of oxygen injection on exhaust gas recirculation (EGR) is investigated. The pressure in the chamber and the equivalence ratio of the mixture are varied from 0.35 MPa to 1.03 MPa and 0.46 to 1.0, respectively. Delco 12620540 spark plug is used as the ignition source and the gas injection into spark plug gap is accomplished ...


Optimization Of Titanium Liquid/Gas Diffusion Layers In Proton Exchange Membrane Electrolyzer Cells, Stuart Mccoy Steen Dec 2015

Optimization Of Titanium Liquid/Gas Diffusion Layers In Proton Exchange Membrane Electrolyzer Cells, Stuart Mccoy Steen

Masters Theses

Polymer electrolyte membrane electrolyzer cells (PEMECs), which are reverse PEM fuel cells (PEMFCs), are effective energy storage medium by producing hydrogen/oxygen from water using electricity from renewable energy sources. This is due in part because of its efficiency, high energy density, compact design, and large capacity. In a PEMEC, a liquid/gas diffusion layer (LGDL) is located between the catalyst layer and the current distributing flow field. The LGDL is expected to transport electrons, heat, and reactants/products to and from the catalyst layer with minimum voltage, current, thermal, interfacial, and fluidic losses. Carbon materials (carbon paper or carbon ...


Impurity Effects In All-Vanadium Redox Flow Batteries, Andrew William Burch Dec 2015

Impurity Effects In All-Vanadium Redox Flow Batteries, Andrew William Burch

Masters Theses

In this dissertation, the effects of VOSO4 [vanadyl sulfate] source and impurities on the beginning-of-life (BOL) performance of an all-vanadium redox flow battery (VRFB) are explored. Battery performance was monitored at 50% state of charge (SOC) using electrolyte with VOSO4 purities of 99%, 99.9% and 99.99% by weight. At cell potentials of 1.23V, the least pure solution yielded the lowest current density of 280 mA/cm2 [square centimeter] and the most pure solution yielded the highest, 560 mA/cm2. The voltage efficiencies and charge-discharge capacities were shown to follow the same trends. Scanning ...


Evaluation Of Fuel Flow Measurement Uncertainty In A Turbine Engine Test Cell, Paul Andrew Wright Dec 2015

Evaluation Of Fuel Flow Measurement Uncertainty In A Turbine Engine Test Cell, Paul Andrew Wright

Masters Theses

The evaluation of measurement uncertainty is an essential part of measurement and data analysis. Measurement uncertainty is itself a measure of the “goodness” of the measured data and helps the analyst to make decisions based on the data. In the turbine engine testing world, accurate measurement of fuel flow is critical. Specific fuel consumption is a combination of thrust and fuel flow and is used to calculate the allowable payload and range of an aircraft as well as the cruising speed. Naturally, test customers (engine manufacturers, aircraft designers, and operators) are very sensitive to the accuracy of fuel flow measurement ...


Cfd Analysis Of Viscosity Effects On Turbine Flow Meter Performance And Calibration, Carl Tegtmeier May 2015

Cfd Analysis Of Viscosity Effects On Turbine Flow Meter Performance And Calibration, Carl Tegtmeier

Masters Theses

In this research turbine flow meters were studied, using computational fluid dynamics (CFD) modeling to the study effects of viscosity on the flow meters, across a wide range of operation, to improve our understanding and their performance. A three-dimensional computational model was created for a typical flow meter geometry. The work began with a steady state model to provide an acceptable initial condition for further simulations. These results were input into a transient model that has a rotating zone around the rotor to provide insight into the interaction between static and rotational structures. In order to automatically adjust the rotor ...


Phase Dynamics Of Locset Control Methodology, Brendan Neschke May 2015

Phase Dynamics Of Locset Control Methodology, Brendan Neschke

Masters Theses

Single-mode fiber amplifiers produce diffraction-limited beams very efficiently. Maximum beam intensity requires that an array of these amplifiers have their beams coherently combined at the target. Optical path differences and noise adversely affect beam quality. An existing closed loop phase control methodology, called the locking of optical coherence by single-detector electronic-frequency tagging (LOCSET), corrects phase errors in real time by electronically detecting path length differences and sending signals to lithium niobate phase adjusters. Broadening the line-width using “jitter” of the input signal can increase the output power of an individual amplifier by suppressing nonlinearity. The system dynamics of LOCSET are ...


Impact Of Solidification On Tensile Strength Of Cocr 2lc In Selective Laser Melting, Stefan Robert Popp May 2015

Impact Of Solidification On Tensile Strength Of Cocr 2lc In Selective Laser Melting, Stefan Robert Popp

Masters Theses

Selective laser melting (SLM) is an additive manufacturing technique with which parts of nearly arbitrary shape and complexity can be produced. The parts are generated layer for layer directly out of a 3D CAD model completely without forming tools.

In this work, the selective laser technique is applied to a CoCrMo alloy. Due to its high corrosion resistance, wear-resistance, and heat resistance, this alloy is mainly used for medical or high temperature applications.

A systematic approach is used to investigate the influence of the process parameters laser power and exposure time (pulsed laser) on density, melt pool dimensions, melt pool ...


Validation Of A Modified Parallel Compressor Model For Prediction Of The Effects Of Inlet Swirl On Compressor Performance And Operability, Reggie Floyd Dec 2014

Validation Of A Modified Parallel Compressor Model For Prediction Of The Effects Of Inlet Swirl On Compressor Performance And Operability, Reggie Floyd

Masters Theses

Engine inlet distortion complications have plagued the turbine engine development community for decades, and engineers have developed countless methods to identify and combat the harmful effects of inlet distortion. One such type of distortion that has gained much attention in recent years is known as inlet swirl, which results in a significant flow angularity at the face of the engine. This flow angularity can affect the pressure rise and flow capacity of the fan or compressor, and subsequently affect compressor and engine performance.

Previous modeling and simulation efforts to predict the effect inlet swirl can have on fan and compressor ...


Design And Model Of The Frame For Hagrid (Hybrid Array Of Gamma Ray Detectors), Santiago Munoz Dec 2014

Design And Model Of The Frame For Hagrid (Hybrid Array Of Gamma Ray Detectors), Santiago Munoz

Masters Theses

Transfer reactions in inverse kinematics have provided critical information in the study of exotic nuclei. However, transfer reactions with charged particles suffer from poor resolution. The measurement of gamma-rays offers several advantages: they provide not only good resolution in measurements but also other information about the nuclei like lifetimes of unstable states. The combination of these two methods would be the ideal situation to gather information about nuclear structure.

HAGRiD, which stands for The Hybrid Array of Gamma Ray Detectors, is a LaBr3(Ce) [lanthanum bromide crystal with a cerium activator] scintillation array to measure gamma rays from transfer reactions ...


Design And Fabrication Of A Low-Cost Turbine Engine Component Testbed (Tect), Joshua A. Hartman Aug 2014

Design And Fabrication Of A Low-Cost Turbine Engine Component Testbed (Tect), Joshua A. Hartman

Masters Theses

With gas turbine engine testing becoming very expensive because of the increasing complexity involved with the engine, engine subsystems, and test support systems, a low-cost Turbine Engine Component Testbed (TECT) is proposed. This engine build is given the designation J1-H-02. In the present study, a small augmented gas turbine engine (GTE) is constructed. The TECT engine is built with modularity as a key design consideration to allow for flame-tube patterns and augmentor sections to be changed quickly for combustion experiments that have gained impetus due to combustion anomalies/instabilities inherent with future military engine augmentors. This testbed allows for an ...


Formulation And Experimental Verification Of Alternate Calibration Techniques Of The Temperature Dependent Response Of Phosphor Fluorescence, Kelsey Michele Winstead May 2014

Formulation And Experimental Verification Of Alternate Calibration Techniques Of The Temperature Dependent Response Of Phosphor Fluorescence, Kelsey Michele Winstead

Masters Theses

The overall goal of this work is to provide an alternative approach to the thermographic phosphor (TP) time constant calibration method for temperature recovery. In this work two techniques are proposed that retain the pulsed source input used in the standard TP time constant calibration approach but reinterpret the phosphor response taken a fixed distance such that the single-exponential decay assumption is removed. The methods do not require knowledge of key parameters prior to data processing, nor do they involve complicated numerical schemes that attempt to fit data in the low signal-to-noise region of the phosphor response. The approaches do ...


Simulating High Flux Isotope Reactor Core Thermal-Hydraulics Via Interdimensional Model Coupling, Adam Ross Travis May 2014

Simulating High Flux Isotope Reactor Core Thermal-Hydraulics Via Interdimensional Model Coupling, Adam Ross Travis

Masters Theses

A coupled interdimensional model is presented for the simulation of the thermal-hydraulic characteristics of the High Flux Isotope Reactor core at Oak Ridge National Laboratory. The model consists of two domains—a solid involute fuel plate and the surrounding liquid coolant channel. The fuel plate is modeled explicitly in three-dimensions. The coolant channel is approximated as a two-dimensional slice oriented perpendicular to the fuel plate’s surface. The two dimensionally-inconsistent domains are linked to one another via interdimensional model coupling mechanisms. The coupled model is presented as a simplified alternative to a fully explicit, fully three-dimensional model. Involute geometries were ...


Neutron Imaging Of Lithium (Li) Coolants Inside High Temperature Niobium (Nb) Heat Pipes, Brad Harrison Hight May 2014

Neutron Imaging Of Lithium (Li) Coolants Inside High Temperature Niobium (Nb) Heat Pipes, Brad Harrison Hight

Masters Theses

Lithium (Li) behavior inside a high temperature Nb-Li leading edge heat pipe was successfully imaged under induction heating operation via neutron imaging. Startup and cool-down operations gave visual confirmation of bulk Li movement using both gravity assisted and inverted operating orientations. The pipe was imaged during an operation cycle from ambient conditions, heated to a steady state temperature of 908.8 0C, and allowed to cool below 200°C. The experiment was performed at the National Institute of Standards and Technology (NIST) in Gaithersburg, Maryland, and at the Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee.

Tomographic images ...


Thermal Response Characterization And Low Fluid Velocity Measurements Using Specialized In-Situ Thermocouples Via The Loop Current Step Response Method, Alexander Hashem Hashemian May 2014

Thermal Response Characterization And Low Fluid Velocity Measurements Using Specialized In-Situ Thermocouples Via The Loop Current Step Response Method, Alexander Hashem Hashemian

Masters Theses

In this study, a specialized balanced-leads thermocouple was developed to perform in-situ thermal response characterization via the LCSR test method. Thermal response characterization of installed thermocouples is essential in order to obtain accurate positional temperature data in rapid transient applications. An analytical model is presented that fully describes the thermocouple system based on a first-principles approach to the heat transfer physics of the sensor. In conjunction with the LCSR test, the full model presented yields quantifiable characterization parameters useful for determining accurate positional temperature data. It is necessary to employ a balanced-leads thermocouple for this experimental procedure in order to ...


Rotordynamic Analysis Of A Two-Pole Synchronous Motor With Sleeve And Pressure Dam Bearings, Justin Matthew Garrard May 2014

Rotordynamic Analysis Of A Two-Pole Synchronous Motor With Sleeve And Pressure Dam Bearings, Justin Matthew Garrard

Masters Theses

A two-pole synchronous motor was recently rewound for the von Karman Gas Dynamics facility at Arnold Engineering Development Complex, Arnold Air Force Base, Tennessee. After installing the rewound rotor, unexpected vibration amplitudes were recorded during motor checkouts. To resolve this issue, an investigation was initiated to investigate the causes of the vibration issues. The investigation discovered that the original design used sleeve bearings rather than pressure dam bearings. A study was formed to determine the effect of changing the pressure dam bearings back to sleeve bearings. Because only one spare bearing shell existed, the bearing with the highest vibration amplitudes ...


Investigation Of The One-Probe And Two-Probe Calibration Integral Equation Methods Using Experimental Data, Abhay Sanjeev Pande Dec 2013

Investigation Of The One-Probe And Two-Probe Calibration Integral Equation Methods Using Experimental Data, Abhay Sanjeev Pande

Masters Theses

This work aims to expand the applicability of the recently devised physics-based Calibration Integral Equation Method (CIEM) at the University of Tennessee Knoxville, for solving the Inverse Heat Conduction Problem (IHCP) as applied to a one-dimensional domain. Contrary to conventional schemes of solving the IHCP, the CIEM does not require the knowledge of the thermo-physical properties of the domain, sensor characterization and sensor probe locations. The pertinent information is implicitly accounted for via an experimental run. The experimental run ‘calibrates’ the physics of the domain and is called the ‘calibration run’. The net surface heat flux during a real ‘unknown ...


A Novel Approach To Multiphysics Modeling Of Heat And Mass Transfer In Porous Media, Seth Allen Pemberton Dec 2013

A Novel Approach To Multiphysics Modeling Of Heat And Mass Transfer In Porous Media, Seth Allen Pemberton

Masters Theses

This thesis aims to investigate conjugate heat and mass transfer in porous media with an emphasis on textiles. Both hygroscopic materials, those that absorb water vapor, and non-hygroscopic materials are examined. A model was developed that utilizes COMSOL’s equation-based partial differential equation (PDE) interface which allows the user to input any equation(s) to be solved. By the use of experimental and numerical data each part of the model, i.e. flow field, gas diffusion, convection and vapor absorption, is verified. The accuracy of the equation-based unsteady flow field is verified by modeling the flow over a circular cylinder ...