COMPARATIVE TESTS OF MODEL PASSIVE AND COMBINED HEAT SHIELDS

The authors present results of experimental investigations of model pa ssive radiative and combined radiative - evaporative thermal protectio n systems (tps). In determining the optical parameters of both systems they impose a maximum temperature of the underlying structure. It is shown that in the combined tps the thickness of the outer heat shield layer is less by a factor of 2-3 than for the passive case. The weight decrease of the combined tps compared with the passive tps is 14-18% of the latter. The results were obtained for a heat flux duration of a pproximately 60 min, during which period the maximum temperature of th e outer surface of the tps reached 1370 K.