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Investigation Of Pyrolysis Gas Chemistry In An Inductively Coupled Plasma Facility, Corey Tillson 2017 University of Vermont

Investigation Of Pyrolysis Gas Chemistry In An Inductively Coupled Plasma Facility, Corey Tillson

Graduate College Dissertations and Theses

The pyrolysis mechanics of Phenolic Impregnated Carbon Ablators (PICA) makes it a valued material for use in thermal protection systems for spacecraft atmospheric re-entry. The present study of the interaction of pyrolysis gases and char with plasma gases in the boundary layer over PICA and its substrate, FiberForm, extends previous work on this topic that has been done in the UVM 30 kW Inductively Coupled Plasma (ICP) Torch Facility. Exposure of these material samples separately to argon, nitrogen, oxygen, air, and carbon dioxide plasmas, and combinations of said test gases provides insight into the evolution of the pyrolysis gases as ...


Long And Short-Range Air Navigation On Spherical Earth, Nihad E. Daidzic 2017 AAR Aerospace Consulting, LLC

Long And Short-Range Air Navigation On Spherical Earth, Nihad E. Daidzic

International Journal of Aviation, Aeronautics, and Aerospace

Global range air navigation implies non-stop flight between any two airports on Earth. Such effort would require airplanes with the operational air range of at least 12,500 NM which is about 40-60% longer than anything existing in commercial air transport today. Air transportation economy requires flying shortest distance, which in the case of spherical Earth are Orthodrome arcs. Rhumb-line navigation has little practical use in long-range flights, but has been presented for historical reasons and for comparison. Database of about 50 major international airports from every corner of the world has been designed and used in testing and route ...


Disrupting Long-Range Polar Order With An Electric Field, Hanzheng Guo, Xiaoming Liu, Fei Xue, Long-Qing Chen, Wei Hong, Xiaoli Tan 2016 Iowa State University

Disrupting Long-Range Polar Order With An Electric Field, Hanzheng Guo, Xiaoming Liu, Fei Xue, Long-Qing Chen, Wei Hong, Xiaoli Tan

Xiaoli Tan

lectric fields are known to favor long-range polar order through the aligning of electric dipoles in relation to Coulomb's force. Therefore, it would be surprising to observe a disordered polar state induced from an ordered state by electric fields. Here we show such an unusual phenomenon in a polycrystalline oxide where electric fields induce a ferroelectric-to-relaxor phase transition. The nonergodic relaxor phase with disordered dipoles appears as an intermediate state under electric fields during polarization reversal of the ferroelectric phase. Using the phenomenological theory, the underlying mechanism for this unexpected behavior can be attributed to the slow kinetics of ...


Enhancement Of Volumetric Specific Impulse In Htpb/Ammonium Nitrate Mixed Hybrid Rocket Systems, Jacob Ward Forsyth 2016 Utah State University

Enhancement Of Volumetric Specific Impulse In Htpb/Ammonium Nitrate Mixed Hybrid Rocket Systems, Jacob Ward Forsyth

All Graduate Plan B and other Reports

Hybrid rocket systems are safer and have higher specific impulse than solid rockets. However, due to large oxidizer tanks and low regression rates, hybrid rockets have low volumetric efficiency and very long longitudinal profiles, which limit many of the applications for which hybrids can be used. This research investigates a method for increasing the volumetric efficiency and improving the form factor of hybrid rocket systems by a non-combustible load of solid oxidizer to the hybrid fuel grain. Including such oxidizers increases the regression rate of the fuel and lowers the amount of fluid oxidizer needed for optimal combustion. This type ...


Development Of Fault Tolerant Adaptive Control Laws For Aerospace Systems, Andres E. Perez Rocha 2016 Embry-Riddle Aeronautical University

Development Of Fault Tolerant Adaptive Control Laws For Aerospace Systems, Andres E. Perez Rocha

Dissertations and Theses

The main topic of this dissertation is the design, development and implementation of intelligent adaptive control techniques designed to maintain healthy performance of aerospace systems subjected to malfunctions, external parameter changes and/or unmodeled dynamics. The dissertation is focused on the development of novel adaptive control configurations that rely on non-linear functions that appear in the immune system of living organisms as main source of adaptation. One of the main goals of this dissertation is to demonstrate that these novel adaptive control architectures are able to improve overall performance and protect the system while reducing control effort and maintaining adequate ...


Accumulator Volume Sensor Final Project Report, Chris Naughton, Kinwei Yu, Michael George 2016 California Polytechnic State University, San Luis Obispo

Accumulator Volume Sensor Final Project Report, Chris Naughton, Kinwei Yu, Michael George

Mechanical Engineering

Accumulator Volume Sensing Team has developed two sensor designs aimed at detecting the position of the piston within a 4024 accumulator. The two designs include the use of a Renishaw LMA10 magnetic encoder and a SpectraSymbol HotPot linear potentiometer. The magnetic encoder solution drastically increases the accuracy of sensing the piston position compared to the current solutions of both a string-pot and linear variable differential transformer while costing slightly less. The linear potentiometer seeks to provide a solution that drastically decreases the cost compared to the present sensing methods. Both designs call for a modification to one half of the ...


Fundamental Studies Of Electrochemical Reactions And Microfluidics In Proton Exchange Membrane Electrolyzer Cells, Jingke Mo 2016 University of Tennessee, Knoxville

Fundamental Studies Of Electrochemical Reactions And Microfluidics In Proton Exchange Membrane Electrolyzer Cells, Jingke Mo

Doctoral Dissertations

In electrochemical energy devices, including fuel cells, electrolyzers and batteries, the electrochemical reactions occur only on triple phase boundaries (TPBs). The boundaries provide the conductors for electros and protons, the catalysts for electrochemical reactions and the effective pathways for transport of reactants and products. The interfaces have a critical impact on the overall performance and cost of the devices in which they are incorporated, and therefore could be a key feature to optimize in order to turn a prototype into a commercially viable product. For electrolysis of water, proton exchange membrane electrolyzer cells (PEMECs) have several advantages compared to other ...


Generation And Microwave Scattering Diagnostics Of Small Volume Plasmas, Jordan Chase Sawyer 2016 University of Tennessee, Knoxville

Generation And Microwave Scattering Diagnostics Of Small Volume Plasmas, Jordan Chase Sawyer

Doctoral Dissertations

This dissertation focuses on the development of novel generation and microwave scattering diagnostic techniques for small volume plasmas. The small volume plasmas presented in this work fall under the two generalized categories: 1) laser-induced plasmas and 2) non-equilibrium microdischarges.

Chapter I presents the application of microwave scattering theory to laser-induced breakdown in air. The MIE solution to Maxwell’s equations is employed to reveal three distinct phases of the evolution of the laser-induced breakdown in air. Chapter II presents a novel method of quantifying thresholds for laser-induced breakdown. These thresholds are established via total electron number measurement from dielectric calibration ...


Microstructural Analysis Of Thermoelastic Response, Nonlinear Creep, And Pervasive Cracking In Heterogeneous Materials, Alden C. Cook 2016 University of Maine

Microstructural Analysis Of Thermoelastic Response, Nonlinear Creep, And Pervasive Cracking In Heterogeneous Materials, Alden C. Cook

Electronic Theses and Dissertations

This dissertation is concerned with the development of robust numerical solution procedures for the generalized micromechanical analysis of linear and nonlinear constitutive behavior in heterogeneous materials. Although the methods developed are applicable in many engineering, geological, and materials science fields, three main areas are explored in this work. First, a numerical methodology is presented for the thermomechanical analysis of heterogeneous materials with a special focus on real polycrystalline microstructures obtained using electron backscatter diffraction techniques. Asymptotic expansion homogenization and finite element analysis are employed for micromechanical analysis of polycrystalline materials. Effective thermoelastic properties of polycrystalline materials are determined and compared ...


Dynamic Monitoring And Life Prediction Of Internal Strain-Gage Balances, David Leon Yoder 2016 University of Tennessee, Knoxville

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 ...


Dji S-1000 Spreading Wings Octocopter: Determination Of Rotor Downwash Slipstream Size, Jonathan Lemieux 2016 University of Tennessee, Knoxville

Dji S-1000 Spreading Wings Octocopter: Determination Of Rotor Downwash Slipstream Size, Jonathan Lemieux

Masters Theses

The DJI S-1000 Spreading Wings octocopter rotor downwash slipstream area of influence was measured in axial climb conditions and in straight level flight. These data were gathered using a simple apparatus of distributed anemometers and a custom made boom affixed to the drone. Straight level flight tests incurred autopilot oscillations that rendered the data gathering and analysis challenging. The best quality data was acquired during the axial climb flight tests. The axial climbs were conducted in calm winds. It was determined that the axial climbs under these conditions displaced the rotor slipstream 9 ± 2.5 cm to the rear of ...


The Design And Computational Validation Of A Mach 3 Wind Tunnel Nozzle Contour, Sarah Elizabeth Adams 2016 University of Tennessee, Knoxville

The Design And Computational Validation Of A Mach 3 Wind Tunnel Nozzle Contour, Sarah Elizabeth Adams

Masters Theses

The objective of this effort was to design and validate a Mach 3 wind tunnel nozzle contour. The nozzle will be used for an existing facility, replacing a Mach 2.3 nozzle. The nozzle contour was design using the widely-distributed CONTUR code developed by Sivells. The program uses a combination of analytical solutions and the method of characteristics in order to calculate a nozzle contour. A nozzle contour adhering to the existing geometry requirements was achieved through an iterative process. The flowfield of the finalized nozzle contour was solved using ANSYS fluent. The solution results were analyzed for flow uniformity.


Nanostructured Morphologies In Glassy Polymer Networks, Brian Greenhoe 2016 University of Southern Mississippi

Nanostructured Morphologies In Glassy Polymer Networks, Brian Greenhoe

Dissertations

The body of this work describes a novel approach for the dispersion of multi-walled carbon nanotubes in a high Tg epoxy prepolymer matrix using a twin screw high-shear continuous reactor. The method demonstrated improves on previous dispersion methods in several ways. It offers increased efficiency through excellent heat transfer, while being solvent-less, scale-able, and tailorable to drive dispersion states to judiciously chosen dispersion states. Furthermore, it was shown that dispersion state and agglomerate morphology can be directed, in several ways, through processing conditions and also by controlling the matrix viscosity profile through cure. Broadband dielectric spectroscopy, optical hot-stage microscopy ...


Determination Of Aqueous Surfactant Solution Surface Tensions With A Surface Tensiometer, Remelisa Esteves, Birce Dikici Ph.D, Matthew Lehman, Qayyum Mazumder, Nonso Onukwuba 2016 Embry-Riddle Aeronautical University

Determination Of Aqueous Surfactant Solution Surface Tensions With A Surface Tensiometer, Remelisa Esteves, Birce Dikici Ph.D, Matthew Lehman, Qayyum Mazumder, Nonso Onukwuba

Beyond: Undergraduate Research Journal

Surfactant solutions are applicable to engineering systems for cooling equipment for electronics. Surfactants can be added to water to improve heat transfer. An application of using aqueous surfactant solutions can be through microchannel heat sink. Although it is ideal to redesign these systems to reduce heat, it is a costly method. Surfactant solutions at optimal solution concentration can be able to transfer heat quickly and effectively with minimum expense. The surface tension of surfactant solutions is an important parameter for boiling heat transfer and must be taken into consideration. The purpose of this research is to measure surface tension of ...


Determination Of Surfactant Solution Viscosities With A Rotational Viscometer, Remelisa Esteves, Nonso Onukwuba, Birce Dikici Ph.D 2016 Embry-Riddle Aeronautical University

Determination Of Surfactant Solution Viscosities With A Rotational Viscometer, Remelisa Esteves, Nonso Onukwuba, Birce Dikici Ph.D

Beyond: Undergraduate Research Journal

Aqueous surfactant solutions are used in engineering systems for improving boiling heat transfer. The purpose of this research is to determine the viscosities of surfactant solutions and to investigate the effect of composition on viscosity. The results obtained can possibly be used as reference for further study in the effects of surfactant solution viscosities on nucleate boiling. A rotational viscometer was used to determine the viscosities of three surfactant solutions – SLS, EH-14, and SA-9 – of various compositions at room temperature. It was discovered that the viscosities of SLS, EH-14, and SA-9 had a nearly consistent pattern as their compositions increased ...


Propulsion Theory Of Flapping Airfoils, Comparison With Computational Fluid Dynamics, Doug F. Hunsaker, W. F. Phillips 2016 Utah State University

Propulsion Theory Of Flapping Airfoils, Comparison With Computational Fluid Dynamics, Doug F. Hunsaker, W. F. Phillips

Doug Hunsaker

It is shown that the time-dependent aerodynamic forces acting on a flapping airfoil in forward flight are functions of both axial and normal reduced frequencies. The axial reduced frequency is based on the chord length, and the normal reduced frequency is based on the plunging amplitude. Furthermore, the time-dependent aerodynamic forces are related to two Fourier coefficients, which are evaluated here from computational results. Correlation equations for these Fourier coefficients are obtained from a large number of grid- and time-step-resolved inviscid computational-fluid-dynamics solutions, conducted over a range of both axial and normal reduced frequencies. The correlation results can be used ...


Commercial Space Situational Awareness (Ssa) Capabilities And Their Benefits For Civilian Space Traffic Management (Stm), Mark A. Skinner 2016 Boeing

Commercial Space Situational Awareness (Ssa) Capabilities And Their Benefits For Civilian Space Traffic Management (Stm), Mark A. Skinner

Space Traffic Management Conference

Paralleling (but lagging) satellite development, SSA, long the sole domain of sophisticated militaries, now includes commercial providers. These commercial capabilities, identified as beneficial to the sustainable use of outer space[1], have demonstrated technical sophistication sufficient to positively contribute to the mitigation of satellite interference and provide actionable SSA information. Utilizing small optical telescopes, these entities are able to determine the orbits of objects in the geosynchronous orbit (GSO) to sizes as small as 1 m2, with measured positional uncertainties of 10s of meters, on the order of the size of a modern communications satellite. These techniques can benefit ...


Spaceways: Airspace In Outer Space, Scott Haeffelin 2016 Embry-Riddle Aeronautical University

Spaceways: Airspace In Outer Space, Scott Haeffelin

Space Traffic Management Conference

Forecasted future demand in space travel is driving the need for the development of space traffic management. Currently, orbital space traffic is mostly unregulated with internationally agreed upon best practices and self-interest driving space operators to avoid collisions with other spacecraft. This paper explores the future of space travel by presenting a concept of creating “airspace in space” or spaceways to manage the ever growing volumes of space traffic. Spaceways are analogous to airspace for aircraft with the goal of increasing levels of safety and reducing probabilities of collision. These goals can be achieved by creating traffic rules, defining valuable ...


A Novel Approach For Controlled Deorbiting And Reentry Of Small Spacecraft, Larry H. Fineberg, Justin Treptow, Timothy Bass, Scott Clark, Yusef Johnson, Bradley Poffenberger 2016 NASA Launch Services Program

A Novel Approach For Controlled Deorbiting And Reentry Of Small Spacecraft, Larry H. Fineberg, Justin Treptow, Timothy Bass, Scott Clark, Yusef Johnson, Bradley Poffenberger

Space Traffic Management Conference

No abstract provided.


Space Analysis And Research Centers (Sparcs) For Ssa Data And Analytics, Phillip Cunio, Brien Flewelling 2016 ExoAnalytic Solutions, Inc.

Space Analysis And Research Centers (Sparcs) For Ssa Data And Analytics, Phillip Cunio, Brien Flewelling

Space Traffic Management Conference

Widespread use of massive data and increasing reliance on spaceborne infrastructure are two of the emerging megatrends of the early 21st century. However, both come with liabilities: movement and processing of large data volumes is very expensive, and reliance on spaceborne infrastructure adds risk that problems in the still incompletely-understood space domain might cause work disruptions.

ExoAnalytic proposes the use of Space Analysis and Research Centers (SpARCs) as a way to begin addressing both these issues. A SpARC is a facility which integrates volumes of data collected on satellites, centrally analyzes it, and makes available resulting useful information. The ...


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