Engineering Commons^™

Analysis Of An Electrospray Thruster With A Concave Propellant Meniscus, Adam Nicholas Huller

Masters Theses

The low thrust, high specific impulse, and low mass of electrospray thrusters (ETs) make them ideal for maneuvering nanosatellites, especially with the new requirement to deorbit a satellite within five years of completing its mission. These innovative thrusters use electrohydrodynamic principles of electrospray (ES) to provide thrust. These principles have been subject to much research over the past decade, though much more research is needed to fully understand the underlying physics of these thrusters. The first part of this study establishes a procedure for analyzing the theoretical thrust performance of an ET, by using propellant properties and well-documented ES scaling …

Boundary Layer Measurements On The Bolt Ii Geometry Using Pressure And Temperature Sensitive Paints, Jacob Gaetano Butera

Masters Theses

Hypersonic vehicles are subjected to an extreme aerothermodynamic environment dominated by intense thermal loading which is amplified further when the local boundary layer state transitions from a laminar to a turbulent state. Due to weight and complexity considerations, it is not feasible to incorporate thermal protection systems (TPS) over an entire hypersonic body. Therefore, it is critically important to identify and predict where the boundary layer will undergo transition such that the thermal protection system can be focused on the most at-risk areas. This work attempts to observe boundary layer transition on the Boundary Layer Transition (BOLT) II flight test …

A Computational Analysis Of Hypersonic Store Separations, Ryan C. Savery

Masters Theses

Many current hypersonic vehicles involve shrouds, fairings, boosters, or ejectable payloads separating during flight. It is imperative that they do not strike each other after separation as this typically results in damage or loss of vehicle. This requires a detailed understanding of the flow features involved such as shock waves, expansion waves, shock reflections, and shock wave boundary layer interactions influencing the vehicles' attitude and trajectory. Experimental and flight tests of these scenarios are costly and need massive infrastructure which require difficult measurement techniques to characterize the flow field. Alternatively, numerical simulations can provide accurate, low-cost, and efficient predictions of …

Flow Control Over An Airfoil Using Synthetic Jet, Satyam Anil Mistry

Masters Theses

In this study, the unsteady, turbulent flow over NACA 0015 was analyzed using synthetic jets. The study focused on applying the numerical method using the commercial CFD solver Ansys Fluent. The synthetic jet simulation was carried out for Re = 896,000 for two angles of attack: 10 and 14 degrees. The optimal jet amplitude and jet frequency were determined from a range of amplitudes of 2.0 to 4.0 and frequencies of 0.4 Hz to 1.2 Hz while the jet location, jet angle, and jet width were fixed. The results showed that for both angles, the optimal amplitude and frequency were …

Deep Space Mission Opportunities To Planet Nine & Eris, Allison G. Carroll

Masters Theses

This research focuses on interplanetary mission design concepts, with the first topic being the study of mission opportunities to Planet Nine, otherwise known as Planet X. Previous studies have speculated about the existence of a large, distant planet beyond the orbits of Neptune and Pluto. A recent study based on the apparent clustering of perihelia and orbital planes of distant Kuiper Belt Objects identified the most probable values for five of the planet’s orbital elements. However, the true anomaly is still unknown. In this research, a range of critical mission parameters for a Planet X trajectory is analyzed as a …

Wast3d Potential, Andrew Larsen

Masters Theses

Waste is obsolete. Standard building industry practices are harmful to the environment. Non-traditional construction methods were examined as alternatives. Circular design logic was the guiding principle in material choice. Additive manufacturing is a proven modern method for building construction. Research on 3D printing case studies revealed that recycled plastic is a proven material and readily available. Removing plastic waste from the environment and sequestering it in architectural components gives the material a new purpose. The component of focus was a building block for a wall assembly. Inspiration was taken from the hexagonal Basalt rock formations found near volcanic fault lines. …

Enabling Premixed Hydrogen-Air Combustion For Aeroengines Via Laboratory Experiment Modeling, Christopher James Caulfield

Masters Theses

All combustion systems from large scale power plants to the engines of cars to gas turbines in aircraft are looking for new fuel sources. Recently, clean energy for aviation has come into the foreground as an important issue due to the environment impacts of current combustion methods and fuels used. The aircraft industry is looking towards hydrogen as a new, powerful, and clean fuel of the future. However there are several engineering and scientific challenges to overcome before hydrogen can be deployed into the industry. These issues
range from storing the hydrogen in a viable cryogenic form for an aircraft …

An Experimental Investigation Of The Effect Of Narrowband Freestream Noise On Fundamental Transitional Shockwave-Boundary Layer Interaction Mechanisms, Zane Matthew Shoppell

Masters Theses

Recent work at the University of Tennessee Space Institute has demonstrated that the resonant behavior observed in the spectra of cylinder- and blunt-fin-generated XSBLIs is connected to fundamental fluid mechanisms within the boundary layer. Therefore, a test campaign was conducted to characterize the fundamental mechanisms that drive the low-frequency unsteadiness in cylinder- and blunt-fin-generated shockwave-boundary layer interactions, specifically shockwave-boundary layer interactions in which the incoming boundary layer is undergoing a laminar-to-turbulent transition. This research aims to develop a deeper understanding of such interactions and characterize the resonant behavior observed in past work by varying the sweepback angle of a hemicylindrical …

Exploring The Structure And Dynamics Of Shock/Turbulent Boundary Layer Interactions Generated By Swept Compression Ramps In A Mach 2 Freestream, Daniel S. Allen

Masters Theses

This thesis reports the investigation of the unsteadiness of a 2D and 3D swept shock-wave/turbulent boundary layer interaction (STBLI) and the effect the extent of subsonic flow has on the separation location. Two swept compression ramp cases are investigated at Mach 2 freestream conditions – a high sweep of 30 degrees and a low sweep of 10 degrees both having the same compression angle of 22.5 degrees in the vertical plane. Using a number of diagnostic techniques including stereoscopic and planar particle image velocimetry (PIV) and unsteady pressure sensitive paint (PSP) anchored with pressure transducers, the unsteadiness, the extent of …

Tailoring A System Engineering And Management Plan For A University Satellite Team, Jacob D. Anderson

Masters Theses

"A Systems Engineering and Management Plan (SEMP) helps enable a successful engineering project or team. All university teams working on satellite development encounter similar obstacles that are not commonly seen in industry. As a result, university teams must determine new approaches to solve these unique and difficult problems. A SEMP can mitigate risks, solve problems, and provide streamlined solutions. A modified SEMP is proposed along with guidance for implementing it into a new team and an existing team.

The adopted SEMP provides a road map for the technical execution and program management of a university team. The SEMP should be …

Flight Software Development For A University-Class Microsatellite Mission, Yumeka Nagano

Masters Theses

"The purpose of this research is to present the software development process used by the Command and Data Handling (C&DH) subsystem as a part of a microsatellite mission underway at the Missouri University of Science and Technology. The mission's objective is to evaluate the performance of an innovative cold gas propulsion system for use in formation flying applications and the incorporation of a stereoscopic imaging sensor used to measure the satellite pair's relative position and velocity vectors in real time. C&DH uses a Raspberry Pi 3 Model B as the flight computer running a Linux environment, and the flight code …

Implementing Effective University - Level Small Satellite Assembly, Integration, And Testing Procedures, Tyler Patrick Hoover

Masters Theses

"As applications for satellite assets grow within government and commercial spheres, demand for aerospace engineers and related technicians has pushed universities to develop graduates with relevant knowledge in the field. As such, universities began to grow university satellite programs to give members hands-on experience and a background of working on satellite systems before entering the workforce.

The M-SAT team at Missouri University of Science and Technology, along with contributions and assistance from the Air Force Research Laboratory and NASA, are progressing their first satellite mission through assembly, integration, and testing (AIT) development. This document serves to give a background into …

The Design And Development Of A Miniature Gridded Ecr Ion Thruster, Nicholas Nuzzo

Masters Theses

Plasma propulsion, a specific subset of electric propulsion (EP), is a class of space propulsion that produces plasma by excitation of a propellant at or above its ionization energy. This ionized propellant is then accelerated by an externally applied field (magnetic and/or electric) and produces thrust. There is an increasing need for miniaturization in spacecraft technology and the use of plasma EP devices in space propulsion. These systems provide an advantage over traditional chemical propulsion solutions which are less efficient and have more mass. Miniaturization of EP devices allows missions to have more space and mass available for their payloads …

Upscaling And Development Of Linear Array Focused Laser Differential Interferometry For Simultaneous 1d Velocimetry And Spectral Profiling In High-Speed Flows, Kirk Davenport

Masters Theses

In this research a new configuration of linear array-focused laser differential interferometry (LA-FLDI) is described. This measurement expands on previous implementations of LA-FLDI through the use of an additional Wollaston prism. This additional prism expands the typical single LA-FLDI column into two columns of FLDI point pairs. The additional column of probed locations allows for increased spatial sampling of frequency spectra as well as the addition of simultaneous wall normal velocimetry measurements. The new configuration is used to measure the velocity profile and frequency content across a Mach 2 turbulent boundary layer at six wall normal locations simultaneously. Features of …

Analysis Of Turbulent Flow Behavior In Helicopter Rotor Hub Wakes, Forrest Mobley

Masters Theses

The rotor hub is one of the most important features of all helicopters, as it provides the pilot a means for controlling the vehicle by changing the characteristics of the main and tail rotors. The hub also provides a structural foundation for the rotors and allows for the rotor blades to respond to aerodynamic forces while maintaining controllability and stability. Due to the inherent geometry and high rate of rotation, the rotor hub in its current form acts a large bluff body and is the primary source of parasite drag on the helicopter, despite its relatively small size. The rotor …

Quasi-One-Dimensional Flow Method For Nuclear Thermal Propulsion Simulator Design, Ethan M. Long

Masters Theses

Quasi-One-Dimensional flow methods are commonly used to solve flow situations that have multiple driving influences, i.e. heat transfer, area change, and friction. They hold advantages over other computational fluid dynamics methods due to their much lower computational costs and overall simplicity. Typically, these methods are limited in their ability to solve flows due to the simplifying assumptions used. In this model, a simple heat transfer calculation is combined with NASA’s Chemical Equilibrium with Applications to constantly update chemical properties within the simulation. In this thesis, a quasi-one-dimensional model including these additions is developed and applied to a NTP simulator design …

A Numerical Optimization Study Of A Novel Electrospray Emitter Design, Joshua H. Howell

Masters Theses

The low thrust and high specific impulse of electric propulsion has been brought to the forefront for CubeSat and small spacecraft applications. Electrospray thrusters, which operate via electrostatic principles, have seen much research, development, and application in recent years. The small sizes of the spacecraft that utilize electrospray thrusters has focused development into the miniaturization of this technology to the micro-scale. Miniaturization introduces design challenges that must be addressed, including power supply mass and footprint requirements. This consequence requires investigation into the effects of design choices on the thruster onset voltage, defined as the voltage at which ion emission begins. …

Path Planning And Flight Control Of Drones For Autonomous Pollination, Chapel R. Rice

Masters Theses

The decline of natural pollinators necessitates the development of novel pollination technologies. In this thesis, a drone-enabled autonomous pollination system (APS) that consists of five primary modules: environment sensing, flower perception, path planning, flight control, and pollination mechanisms is proposed. These modules are highly dependent upon each other, with each module relying on inputs from the other modules. This thesis focuses on approaches to the path planning and flight control modules. Flower perception is briefly demonstrated developing a map of flowers using results from previous work. With that map of flowers, APS path planning is defined as a variant of …

Dynamic Maneuvers For Satellite On-Orbit Servicing Utilizing Novel Continuum Robotics: Development & Experimentation, Nathan Dalton

Masters Theses

Robotic on-orbit servicing is a developing technology that seeks to increase the longevity and repairability of faulty or aging resident space objects. In this research, the development of a flexible continuum manipulator for a small satellite system that performs low-complexity on-orbit servicing or debris removal is presented. Derivations of manipulator kinematics are described in detail, a non-linear control scheme has been developed, and the accuracy and servicing applications for the prototype are evaluated and discussed. The manipulator has been tested on an air-bearing dynamics simulator, and the results are extensively analyzed. System recommendations and future work suggestions are presented.

Design And Optimization Of An Electron Cyclotron Resonance Thruster, Austen Thomas

Masters Theses

Presented in this work is the process in the design and optimization of a coaxial electron cyclotron resonance thruster. Electron cyclotron resonance thrusters are novel microwave-based thrusters which possess select technological advantages over mature electric propulsion concepts such as being electrodeless and only requiring a single power source. The thruster constructed in this work is a coaxial configuration and is termed the Western electron cyclotron resonance thruster. Thruster dimensions were optimized based on past experimentation completed with ECR thrusters. In an attempt to enhance the microwave plasma coupling of the coaxial thruster design three different antenna configurations were considered: a …

Numerical Investigations Of 2-D Magnetic Nozzles On Pulsed Plasma Plumes, Joshua Daniel Burch

Masters Theses

"This research presents studies of a novel type of magnetic nozzle that allows for three-dimensional (3-D) steering of a plasma plume. Numerical simulations were performed using Tech-X's USim® software to quantify the nozzle's capabilities. A2-D planar magnetic nozzle was applied to plumes of a nominal pulsed inductive plasma (PIP) source with discharge parameters similar to those of Missouri S&T's Missouri Plasmoid Experiment (MPX). Argon and xenon plumes were considered. Simulations were verified and validated through a mesh convergence study as well as comparison with available experimental data. Periodicity was achieved over the simulation run time and phase angle samples were …

Thermodynamic Analysis Of An Autogenous Pressurization System, Samuel H. Smith

Masters Theses

Pressurized gas feed systems have been vital to spacecraft where a pump-fed design would prove too large, heavy, or complicated to be effective. This project investigates autogenous pressurization – a pressurized feed system where the intentional vaporization of liquid propellant to fill the ever-increasing ullage space with its own warm, low-density gas. Motivation for this research originates from the University of Tennessee Space Institute’s (UTSI) contract with Gloyer-Taylor Laboratories (GTL) to assist the development of an innovative pressurization system.

While other pressurization systems have been studied and used extensively, modeling of an autogenous system is less established. Despite the relative …

Investigation Of The Rupture Initiation And Mechanical Performance Of Alumina Port Covers For Integrated Rocket Ramjet Systems, Haley R. Goldston

Masters Theses

Hypersonic flight is widely considered essential to ensure a competitive defensive capability in the United States. In hypersonic air breathing propulsion, cruise vehicles are a priority research and development area given the ease to which they can be implemented with existing DoD infrastructure. Advancements in ramjet engine systems, including integrated rocket ramjets, play a considerable role in military and space access hypersonic vehicle designs. By design, ramjets cannot produce static thrust. They first need to be brought to operational speeds with the help of a rocket booster. An integrated rocket ramjet (IRR) combines the booster phase and the ramjet phase …

Temperature Sensitive Paint Investigation Of A Cylinder Induced Shockwave Boundary Layer Interaction, Caleb Bell

Masters Theses

A urethane based temperature sensitive paint was employed to measure the surface temperature characteristics of both a cylinder perpendicular to a Mach 2.3 flow and the floor of the tunnel with varying gaps between the base of the cylinder and the tunnel floor. The first goal of this study was to determine the effectiveness of a temperature sensitive paint at providing quantitative and qualitative temperature data on supersonic flow interactions in a standard supersonic blow down wind tunnel. The second goal was to determine the heat transfer and surface temperature of the cylinder and the areas of the tunnel wall …

Composite-Based Additive Manufacturing Applications In The Polymer Injection Molding Cycle, Cody Bivens

Masters Theses

“The experimental method utilized in this research was the application of composite-based additive manufacturing (CBAM) mold plates in the injection molding process. The mold plates comprised carbon fibers and polyether ether ketone (PEEK) matrix. Modifications were made to the mold plates post manufacturing in order to properly adapt to the rest of the injection molding die. A custom cooling system was engineered and integrated into the injection molding machine for the CBAM mold plates. The polymer processed in the injection molding cycle for this study was Lustran 348 acrylonitrile butadiene styrene (ABS). The result of the trials conducted in this …

Multiple-Site Fatigue Cracking Methodology To Assess Structural Integrity Of Aircraft Riveted Panels, Haroldo Chacon

Masters Theses

“Multiple Site Damage (MSD) is the most common source of Widespread Fatigue Damage (WFD) affecting structural integrity of aging aircraft fleets. Therefore, an understanding of its progression, the development of methods to prevent the onset, and the maintenance procedures precluding WFD are important to improve aircraft fleet longevity. A reliable and efficient numerical methodology to perform detailed Multiple Site Damage assessment in riveted structural joints was developed. A probabilistic methodology was employed in conjunction with Monte Carlo simulation technique; the fatigue initiation life at every potential crack initiation site was determined and initial damage scenarios were generated. Probabilistic crack growth …

Development Of A Single Emitter Ionic Liquid Ion Source Research Platform, Thomas V. Kerber

Masters Theses

A single emitter ionic liquid ion source using porous borosilicate glass was developed. Two emitters with different radii of curvatures were tested using 1-ethyl-3-methylimidazolium tetrafluoroborate (EMI-BF₄). I-V curves of the currents on the extractor electrode and a collector plate were obtained for potential differences between the emitter and the extractor ranging from 0 V to 3500 V. For the first emitter chip, extraction began near 2400 V. The highest emission current measured on the first chip was 80 µA at 3500 V with an interception current on the extractor of 4.86 µA. An new collector plate was used …

Investigation Of Predicted Helicopter Rotorhub Drag And Wake Flow With Reduced Order Modeling, Tristan David Wall

Masters Theses

The rotor hub is one of the most important components of the modern helicopter. This complex collection of linkages and plates has numerous responsibilities, including the translation of pilot input to system response, anchoring the blades to the rotor mast, and sustaining the various forces transmitted by the blades. Due its intricate design and relatively small sized components the rotor hub interacts with the incoming flow to create a highly chaotic, turbulent wake which impinges on the fuselage and empennage. This assembly has also been found to be one of the primary contributors to the total vehicle parasite drag. Unfortunately …

An Experimental Investigation Of High-Speed Air-Breathing Vehicle Performance Metrics, Katherine M. Stamper

Masters Theses

High-speed air-breathing vehicles are one of the main hypersonic vehicles currently being developed. There is a current push by major world powers to develop these vehicles and one of the major limiting factors is engine design. The high-speed air-breathing vehicles necessitate an engine that can perform at higher speeds and higher temperatures, such as a scramjet. This engine is broken into three main parts: the inlet, isolator, and combustor. One of the primary concerns for these vehicles is engine unstart, which is when there is no longer supersonic flow through the engine and the engine can no longer perform. This …

Optical Measurements Of Viscous Interactions On A Hollow-Cylinder / Flare In A Mach 4 Freestream, Jack William Cobourn

Masters Theses

Despite decades of research, shock-wave/boundary-layer interactions and laminar-turbulent transition remain uncertainties in the design of hypersonic vehicles. Due to the significant demand for hypersonic capabilities and the relevance of these flow physics to air-breathing, high-lift, hypersonic vehicles, continued study is necessary. In order to support such study at the University of Tennessee Space Institute, two optical diagnostics were investigated for use in the Mach 4 Ludwig tube at the Tennessee Aerothermal Laboratory, focused laser differential interferometry and schlieren. Significant attention was given to the theory behind and application of focused laser differential interferometry to support future work at the University …