Study of the Effects of Heat Load, Ablator Density and Backup Structure upon the Thermal Protection Performance of Heat Shield Systems Consisting of Phenolic Carbon Ablators

Abstract

The effects of heat load, ablator density, and backup structure, etc. upon the heat shield performance of the lightweight phenolic carbon ablators named LATS were investigated using a one-dimensional ablation analysis code. The ablator density was assumed to be from about 260 to 1000kg/m 3 . Heat flux time histories of a rectangular pattern were assumed, where cases of constant heating duration time and constant accumulated heat load (up to 600MJ/m 2 ) were considered. The heating level was assumed to be from 1 to 10MW/m 2 , which means that the ablator surface is in the region of diffusion control oxidation/sublimation. The materials of the backup wall are assumed to be aluminum, stainless steel and high density CFRP. Main findings are: (1) For a low heat flux q with the same heating duration time tq, the necessary thickness, with which the maximum back surface temperature equals to the pre-determined allowable temperature, is nearly constant as the density v changes. On the other hand, the necessary thickness increases largely when q is larger and v is smaller. The ablator necessary mass increases with the increase of v and q for the same tq.