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Boundary Layer Measurements On The Bolt Ii Geometry Using Pressure And Temperature Sensitive Paints, Jacob Gaetano Butera
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 …
An Experimental Investigation Of The Effect Of Narrowband Freestream Noise On Fundamental Transitional Shockwave-Boundary Layer Interaction Mechanisms, Zane Matthew Shoppell
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 …
Development And Implementation Of A Novel Resonantly Ionized Photoemission Thermometry Technique For One-Dimensional Measurements, Walker B. Mccord
Development And Implementation Of A Novel Resonantly Ionized Photoemission Thermometry Technique For One-Dimensional Measurements, Walker B. Mccord
Doctoral Dissertations
In this work, Resonantly Ionized Photoemission Thermometry (RIPT) is established and validated as a novel, non-intrusive, non-seeded, One-Dimensional (1D) line thermometry technique. The RIPT technique resonantly ionizes a target molecule via REMPI (Resonant Enhanced Multi-Photon Ionization) of selectively chosen rotational peaks within a resonant absorption band. Thus, efficiently ionizing and subsequently exciting local nitrogen molecules either by direct or indirect schemes. The excited nitrogen deexcites through photoemissions of the first negative band of N2+[molecular nitrogen], specifically near 390, 425, and 430nm [nanometers], that is then acquired as a 1D line signal. The signal strength at all transitions …
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 …
Characterizing The Unsteady Dynamics Of Cylinder-Induced Shock Wave/Transitional Boundary Layer Interactions Using Non-Intrusive Diagnostics, Elizabeth Lara Lash
Characterizing The Unsteady Dynamics Of Cylinder-Induced Shock Wave/Transitional Boundary Layer Interactions Using Non-Intrusive Diagnostics, Elizabeth Lara Lash
Doctoral Dissertations
The objectives of this study were to provide time-resolved (1) characterizations of shock wave/transitional boundary layer interactions using schlieren flow visualization, and (2) correlations of unsteady shock motion to boundary layer features. The characteristics of cylinder-induced shock wave/transitional boundary layer interactions in a Mach 2 freestream flowfield were studied experimentally. The Reynolds number in the Mach 2 facility was 30,000,000 m-1. Incoming boundary layers were in transitional and fully turbulent states. Characterizing the shock wave motion was based on tracking the position of the shock wave on the model surface in schlieren images. The motion of the shock waves revealed …
Improved Modeling Of Atmospheric Entry For Meteors With Nose Radii Between 5cm And 10m, Jakob Dale Brisby
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 …
A Survey Of Gaps, Obstacles, And Technical Challenges For Hypersonic Applications, Timothy Andrew Barber
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, …
Evaluation Of Geometric Scale Effects For Scramjet Isolators, Jaime Enrique Perez
Evaluation Of Geometric Scale Effects For Scramjet Isolators, Jaime Enrique Perez
Masters Theses
A numerical analysis was conducted to study the effects of geometrically scaling scramjet inlet-combustor isolators. Three-dimensional fully viscous numerical simulation of the flow inside constant area rectangular ducts, with a downstream back pressure condition, was analyzed using the SolidWorks Flow Simulation software. The baseline, or 1X, isolator configuration has a 1” x 2.67” cross section and 20” length. This baseline configuration was scaled up based on the 1X configuration mass flow to 10X and 100X configurations, with ten and one hundred times the mass flow rate, respectively. The isolator aspect ratio of 2.67 was held constant for all configurations. To …