Lateral Wall Pressure Effects in a Transpiration Cooled Scramjet Model Combustor with Shock-Boundary Layer Interaction

Kurzfassung

Cooling experiments are performed by the DLR Institute of Space Propulsion, applying a transpiration cooling system to a scramjet model combustion chamber. Nitrogen and hydrogen coolants are injected through different porous wall samples made of sintered stainless steel into a Mach 2.5 hot gas main flow. Different inlet conditions as well as the response of the static pressure distribution to them at the lateral wall are investigated for the uncooled case and for the maximum blowing ratio for each material together with a shock impingement caused by a 9.3° half wedge. Measurement results obtained by optical (Schlieren, Background Oriented Schlieren) and in-situ measurement systems are compared. Results show a strong independence of the lateral static pressure distribution from the choice of coolant, but not from the coolant intrusion depth and flow path shock pattern. Results show a good agreement with previous results gained for the coolant wake region. Pressure fluctuation phenomena and further research requirements are discussed.