A unified methodology for simulation of aerothermochemistry at gas/solid interfaces

Abstract

A unified numerical methodology is described for problems involving thermal protection systems and aerodynamic heating phenomena.The analysis methodology loosely couples a fluid dynamics model to a surface reaction model through boundary condition treatments. The coupling of the two models is predicated on an understanding of the fundamental physical processes that occur at reacting gas/solid interfaces of various aerospace systems. For problems of interest, a time-dependent analysis (e.g. over a trajectory) is accomplished iteratively through the numerical solution of the compressible reacting NavierStokes equations coupled with phenomenologies that describe the surface kinetic constraints. A key element beyond the integration of the fluid dynamics and surface reaction models is the development of a simplified, computationally manageable, chemical kinetics model for hydrocarbon-air reactions occurring at the surface or in the air stream. This paper focuses on the general approach being taken in developing the unified analysis capability for ablating gas/solid interfaces. It describes the chosen fluid dynamics and material thermal response models and the coupling procedure between the two. Also presented is the status of a blunted cone demonstration problem.