Aerothermodynamic optimization of hypersonic vehicle IPS design by a POD/RSM-based approach

This paper presents an automated 3D design procedure called TPSOPT, the thermal protection system (TPS) optimization for hypersonic vehicle heatshield designs. TPSOPT is imbedded in a hypersonic aerodynamics and aerothermodynamics for TPS (HYAAT) system. Hence the essential modules in HYAAT including the aerodynamics/aerothermodynamics (AA), the TPS sizing, and an AA submodule, as an expedient CFD aerodynamic tool, called proper orthogonal decomposition (POD)/response surface method (RSM) are first reviewed. Aerodynamic and aerothermodynamic data are provided through the POD/RSM-based CFD methodology, thereby it can expediently furnish the surface skin friction/heat transfer coefficients per a given trajectory. The TPS sizing objective is to minimize the TPS weight while satisfying the structural constraints and the thermal protection requirement of a combined RLV/TPS design. With a complex variable differentiator for sensitivity and an optimizer ASTROS, TPSOPT optimizes the TPS thickness distribution by assigned shape functions. Here the number of design variables can be significantly reduced since the coefficients of those shaped functions are determined rather than the thickness variable itself. A modeled X-34 is selected as a case-studied example to demonstrate the TPSOPT methodology. Typical CPU time for each POD-based CFD solution requires only a few second on a PC. TPSOPT for a TPS design solution requires approximately 4 hours per trajectory.