DEVELOPMENT OF ELEMENTS OF REUSABLE HEAT SHIELDS FROM A CARBON–CERAMIC COMPOSITE MATERIAL 1. THEORETICAL FORECAST

For the new generation of space vehicles with a reusable heat shield, it is promising to use carbon-ceramic composite materials resistant to powerful heat fl ows arising by the descent of such a vehicle in the atmosphere. This paper presents the results of the theoretical forecast of characteristics of a heat shield from a porous carbon–ceramic composite made on the basis of testing specimens of this composite on a gas-dynamic stand simulating real operating conditions of the heat shield. Methods have been developed for simulating the heating and ablation of specimens of carbon–ceramic composites under their convective heating in a plasmatron. It has been established that the diameter of the nozzle of the gas-discharge channel of the plasmatron and its distance to the frontal surface of the specimen infl uence the temperature regime of tests. We propose an experimental procedure for attaining a temperature of 273 K on the frontal surface of a cylindrical specimen of a carbon–ceramic composite material of diameter 70 mm and height 70 mm.
   
Author:  S. V. Reznik, P. V. Prosuntsov, and K. V. Mikhailovskii
Keywords:  reusable heat shield, composite porous carbon–ceramic material, thermal tests, gas-dynamic stand, convective heating
Page:  89