Experimental Investigation of Transpiration Cooling in a Subscale Combustion Chamber with Non-Reactive Flow

Abstract

This paper presents the first results of a study of transpiration cooling in a segmented ceramic matrix composite specimen resembling a subscale rocket engine combustion chamber. The tests were conducted with a hot air mainstream flow with a temperature of Thg = 800 K, and cold air as coolant. For the first experiments, a variation of the blowing ratio of F = 0-0.75% was investigated, with constant blowing over all segments. The increase of cooling efficiency with rising blowing ratio is demonstrated. For the nozzle contoured segment, a significant increase of the wall temperature could be determined for low blowing ratios, which can be attributed to cross-flows caused by the higher pressure gradient in the expansion section.