Engineering Commons^™

Heat Transfer Analysis Via Rate Based Sensors, Jake Erik Plewa

Masters Theses

This work presents an integrated rate-based sensor and method for resolving the surface heat flux of a fundamental inverse heat conduction problem without numerical regularization or differentiation in a semi-infinite geometry that additionally accounts for thermocouple delay due to its intrinsic time constant. The sensor uses well-designed analog filters to directly regularize raw voltage data to eliminate the need for numerical regularization methods. The sensor can also be used in a series of well-designed voltage-rate interfaces that directly measure the voltages from in-depth thermocouples, which are used in conjunction with the thermocouple calibration curve to provide higher-time derivatives of the …

Parametric Instability Investigation And Stability Based Design For Transmission Systems Containing Face-Gear Drives, Meng Peng

Doctoral Dissertations

The objective of this dissertation is to provide a novel design methodology for face-gear transmissions based on system stability - a dynamics viewpoint. The structural dynamics models of transverse and torsional vibrations are developed for face-gear drives with spur pinions to investigate the parametric instability behavior in great depth. The unique face-gear meshing kinematics and the fluctuation of mesh stiffness due to a nonunity contact-ratio are considered in these models. Since the system is periodically timevarying, Floquet theory is utilized to solve the Mathieu-Hill system equations and determine the system stability numerically. To avoid complex numerical computations, Treglod’s approximation is …

On Compressible Gaseous Motions In Swirl Dominated Combustors, Brian A. Maicke

Doctoral Dissertations

In this dissertation, a number of models are derived to describe swirling flows. Both generalized compressible Bragg-Hawthorne and vorticity-stream function frameworks are determined and left in a generic form suitable for describing a number of different scenarios. These systems are solved for the bidirectional vortex flowfield by means of a Rayleigh-Janzen perturbation, which expands the governing equations in terms of the Mach number squared. The resulting equations are solved to provide a semi-analytical solution after the evaluation of a handful of numerical integrals. These solutions further the understanding of compressible flow in swirl-combustors, as previous compressible studies are primarily experimental …

Simulating The Effects Of Outer-Mold-Line Modification On The University Of Tennessee Space Institute's Aviation Systems' Piper Navajo Research Aircraft, Jonathan Vincent Kolwyck

Masters Theses

Aircraft used as research platforms often have their Outer-Mold-Lines (OML) modified to accommodate instrumentation packages associated with the research being performed. The external modification will change the aerodynamics of the aircraft, thus altering how the aircraft flies. The resulting performance, stability, and control of the aircraft can be effectively determined, but pilot opinion of aircraft handling qualities are largely unknown. The objective of this project is to be able to simulate aircraft flight control systems in the UTSI simulator, thus enabling the evaluation of pilot opinion of handling qualities. The design and implementation of a control loading system is described, …

Design Of Cessna 210 Radome-Pod Instrument Interface For Flight Testing, Lumumba Thutmose O. Obika

Masters Theses

The purpose of this study was to determine the most appropriate location and design for an instrument interface that can utilize minimum volume within a Cessna 210 wing-pod. This study considered some instruments such as a radiometer, heitronics pyrometer, laser altimeter and a network camera; to develop a suitable instrument interface. The study examined the process needed to implement a design methodology for instrument interfaces for flight testing. The study combined varying physiological factors to produce a design for the internal-instruments’ interface of a wing pod. These factors include but may not be limited to simulated analysis, impact on human …

Humanitarian Response Unmanned Aircraft System (Hr-Uas), Justin T. Knott, David P. Brundage, John S. Campbell, D. Austin Eldridge, Shaun B. Hooker, Jake R. Mashburn, Jacob L. Philpott

Chancellor’s Honors Program Projects

No abstract provided.

A Method For Performance Analysis Of A Ramjet Engine In A Free-Jet Test Facility And Analysis Of Performance Uncertainty Contributors, Kevin Raymond Holst

Masters Theses

Ramjet and scramjet engines are being developed to provide a more fuel efficient means of propulsion at high Mach numbers. Part of the development of these engines involves test and evaluation of an engine in ground facilities as well as in flight. Ground facilities, like Arnold Engineering Development Center (AEDC) and those at engine manufacturers like General Electric (GE) and Pratt & Whitney (PW), have decades of experience testing traditional turbine engines and much less experience testing full scale ramjet engines.

Testing a supersonic engine model in a free-jet mode presents a host of challenges not experienced during traditional direct …

A Survey Of Mission Opportunities To Trans-Neptunian Objects – Part Ii, Ashley M. Gleaves

Chancellor’s Honors Program Projects

No abstract provided.

A Survey Of Gaps, Obstacles, And Technical Challenges For Hypersonic Applications, Timothy Andrew Barber

Masters Theses

The object of this study is to canvas the literature for the purpose of identifying and compiling a list of Gaps, Obstacles, and Technological Challenges in Hypersonic Applications (GOTCHA). The significance of GOTCHA related deficiencies is discussed along with potential solutions, promising approaches, and feasible remedies that may be considered by engineers in pursuit of next generation hypersonic vehicle designs and optimizations. Based on the synthesis of several modern surveys and public reports, a cohesive list is formed, consisting of widely accepted areas needing improvement and falling under several general categories. These include: aerodynamics, propulsion, materials, analytical modeling, CFD modeling, …

Fault Diagnosis Via Univariate Frequency Analysis Monitoring: A Novel Technique Applied To A Simulated Integrated Drive Generator, Brian Keith Bailey

Masters Theses

The purpose of this research was to develop a fault detection and diagnostic method that would be able to detect and isolate seeded faults in data that was generated from a simulated integrated drive generator. The approach to the solution for this problem is summarized below.

A novel approach for the detection and diagnoses of an anomaly due the occurrence of a fault within a system has been developed. This innovative technique uses specific characteristics of the frequency spectrum of a univariate signal to monitor system health for abnormal behavior due to previously characterized component failure.

A fault detection and …

Development And Verification Of A Navier-Stokes Solver With Vorticity Confinement Using Openfoam, Austin Barrett Kimbrell

Masters Theses

Vorticity Confinement (VC) is a numerical technique which enhances computation of fluid flows by acting as negative diffusion within the limit of vortical regions, preventing the inherent numerical dissipation present with conventional methods. VC shares similarities with large eddy simulation (LES), but its behavior is based on a stable negative dissipation of vortical structures controlled by the automatic balance between two parameters, μ [mu] and ε [epsilon].

In this thesis, three-dimensional, parallel-computing Navier-Stokes solvers with VC are developed using the OpenFOAM computational framework. OpenFOAM is an open-source collection of C++ libraries developed for computational fluid dynamics. Object-oriented programming concepts are …

Droplet Characterization In The Wake Of Steam Turbine Cascades, Adam Charles Plondke

Masters Theses

In low-pressure steam turbines, water droplet formation on the surfaces of stationary stator blades can lead to erosion on downstream turbine blades and other equipment. One property that affects the size of the droplets that are formed is the adhesive forces between the water and the surface of the stator blade. The adhesive forces hold the droplets to the surface where they may combine, forming increasingly larger droplets. Eventually, the aerodynamic forces will tear the droplets off the surface, carrying them downstream.

To study the effect of stator surface properties on the droplet size distribution, four cascades of stator blades …

Optimization And Design For Heavy Lift Launch Vehicles, Paul Andreas Ritter

Masters Theses

The simulation and evaluation of an orbital launch vehicle requires consideration of numerous factors. These factors include, but are not limited to the propulsion system, aerodynamic effects, rotation of the earth, oblateness, and gravity. A trajectory simulation that considers these different factors is generated by a code developed for this thesis titled Trajectories for Heavy-lift Evaluation and Optimization (THEO). THEO is a validated trajectory simulation code with the ability to model numerous launch configurations. THEO also has the capability to provide the means for an optimization objective. Optimization of a launch vehicle can be specified in terms of many different …