Materials for self-transpiring hot skins for hypersonic vehicles or reusable space vehicles

Abstract

A self-transpiring hot skin for a hypersonic or reusable space vehicle that can provide protection to the vehicle during short periods of abnormally high heat flux (either planned in the flight profile or an off-nominal event). The hot skin includes a ceramic composite structure having an internal cavity that is coupled either to the insulating layer or directly to the support structure of the hypersonic vehicle. The internal cavity includes a material system that vaporizes, sublimes or decomposes into a gas when the temperature exceeds the upper temperature capability of the composite material. The gas transpires through the outer layer of the composite material to provide cooling to the outer layer below the upper temperature capability. Cooling may occur both by conduction of heat from the composite material to the transpiring gas and by the interaction of the transpiring gas with the boundary layer of hypersonic flow over the outer surface, leading to a reduction of the heat flux entering the surface.