Committee Chair

Sreenivas, Kidambi

Committee Member

Margraves, Charles; Newman, James

Department

Dept. of Mechanical Engineering

College

College of Engineering and Computer Science

Publisher

University of Tennessee at Chattanooga

Place of Publication

Chattanooga (Tenn.)

Abstract

Hypersonic flow over cavities results in instabilities and discontinuities that affect the surface properties, and potentially results in surface damage. Simulations were performed using semi-structured 2D meshes in FUN3D with the Spalart-Allmaras and Menter Shear Stress Transport turbulence models at a freestream Mach number of 10. The geometry includes a flat plate and four cavities with length-to-height (L/H) ratios of 0.17, 5, 15, and 30. The surface heating is found to have a strong sensitivity to freestream Reynolds numbers and some sensitivity to a change in the wall temperature. The cavity flow results are compared to Nestler et al.’s experimental data and Holifield’s CFD results. The cavities with an L/H greater than 1 presented a good match to the experimental data for both heating and pressure. The flow did not fully develop at the bottom of the L/H 0.17 gap, resulting in less accurate results close to the cavity floor.

Acknowledgments

I would like to thank Dr. Kimdambi Sreenivas for believing in me, answering my questions while unveiling a larger puzzle to be solved, and acting as my mentor and committee chair. I would like to thank Dr. Margraves for sparking my interest in compressible flow and helping me decide to continue my education. I would also like to thank my fellow graduate researchers Jason DeHay, James Snuggs, Alexander Snyder, and Timothy Wolfe for their continued support and friendship. Meshing was done using Pointwise meshing software from Cadence Design Systems, Inc., Simulations were run using NASA’s flow solver Fun3D, and post processing tools include FieldView, TecPlot, and MATLAB. The Computational Resources used include the GPU-enabled cluster EPYC provided by the University of Tennessee at Chattanooga SimCenter and funded by the National Science Foundation under Grant Nos. 1925603 and 2201497. Funding for this research was provided through the Reusable Hypersonic Vehicle Structures program by the Air Force Research Laboratory, Aerospace System Directorate, High Speed Systems Division (AFRL/RQH), Prime Contract Number FA8650-18-C-2253.

Degree

M. S.; A thesis submitted to the faculty of the University of Tennessee at Chattanooga in partial fulfillment of the requirements of the degree of Master of Science.

Date

5-2024

Subject

Aerodynamics, Hypersonic; Computational fluid dynamics; Heat engineering; Heat--Transmission; Thermofluid systems

Keyword

Computational Fluid Dynamics; Hypersonics; Surface Heating; Gap Flow; Cavity Flow; FUN3D

Document Type

Masters theses

DCMI Type

Text

Extent

xviii, 150 leaves

Language

English

Rights

http://rightsstatements.org/vocab/InC/1.0/

License

http://creativecommons.org/licenses/by/4.0/

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