Development and testing of a new optimum design code for hypersonic wind tunnel nozzles, including boundary layer, turbulence, and real gas effects.

摘要

A robust and efficient hypersonic nozzle optimization code is developed and validated. The code is used to redesign an existing axisymmetric Mach 12 wind tunnel nozzle and utilizes response surface methodology (RSM) techniques. In the nozzle optimization, only two variable design parameters are used, along with constraints of fixed nozzle length, throat radius and exit radius. Explicit, globally second-order, flux-difference-splitting algorithms are used to solve the 2-D/axisymmetric Navier-Stokes (NS) and Parabolized Navier-Stokes (PNS) flow solvers incorporated into the optimizer code. Either the Baldwin-Lomax or the Yang-Shih k-{dollar}epsilon{dollar} turbulence model may be employed in the nozzle design. The optimization code is developed and validated, and 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.