Date of Award

9-1-2018

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Department of Aeronautics and Astronautics

First Advisor

Robert B. Greendyke, PhD

Abstract

The current resurgence of interest in hypersonic technologies has warranted an inquiry into the commonly employed thermochemical non-equilibrium models within computational fluid dynamic (CFD) simulations. Additionally, research has historically focused on forebody flowfields, while studies of the complex wake structure have remained elusive. Although the forebody is of significance for vehicle analysis, the wake presents many exploitative characteristics. This dissertation aimed to address these two deficits. First, two three-temperature non-equilibrium models were developed, increasing the fidelity of hypersonic solutions above that of the legacy two-temperature model. The models were then investigated via zero-dimensional simulations, to detail the non-equilibrium processes, and ultimately implemented within a CFD architecture and validated against the RAM C-II flight test data. Compared against the two-temperature, the three-temperature models were shown to capture additional physics of the non-equilibrium phenomena; thus, the accuracy of the predicted thermochemical state increased. Second, a parametric study characterizing the wake behind a generic, slender geometry was completed, where the non-equilibrium processes were shown to extend a significant distance into the wake. The complex wake structure, coupled with the high-fidelity three-temperature model, has implications on radiative heating, communications blackout, and remote detection predictions.

AFIT Designator

AFIT-ENY-DS-18-S-059

DTIC Accession Number

AD1063511

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