Date of Award

11-1995

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Department of Aeronautics and Astronautics

First Advisor

John Doty, PhD

Abstract

A robust and efficient optimization code is developed and validated. The code is used to redesign an existing Mach 12 wind tunnel nozzle and utilizes response surface methodology (RSM) techniques. Explicit, globally second-order, flux-difference-splitting algorithms are used to solve the Navier-Stokes (NS) and Parabolized Navier-Stokes (PNS) flow solvers incorporated into the optimizer code. Either the Baldwin-Lomax or the Yang-Shih k-s turbulence model may be employed in the optimization code. First, 2-D/axisymmetric NS and PNS flow solvers are developed/modified and account for perfect gas/nonequilibrium chemically reacting flows. All solvers are validated against Computational Fluid Dynamics (CFD) and experimental data. The optimization code is subsequently developed and validated. The optimization code is then used to optimize the Mach 12 nozzle design and the computed results are compared with those of the original nozzle. The code is tested for robustness and on three separate occasions locates the global minimum synonymous with the `global best' optimized nozzle. Though an optimized nozzle is obtained, it is not as free of disturbances in the uniform inviscid core at the exit as possibly desired.

AFIT Designator

AFIT-DS-ENY-95-05

DTIC Accession Number

ADA306279

Download

Share

COinS