Thermal choke active control in rocket ejector mode and ramjet mode was investigated theoretically and experimentally for the integral design of RBCCengine.Theoretic model for possibility analysis of realizing thermal choke was set up.The effect of combustor geometry

heat adding scheme

flow parameters of the primary and secondary mixture on thermal choke was analyzed.Aprinciple of critical Mach number for determining the possibility of reaching thermal choke was proposed.Both theoretical results and experimental results show that it's difficult to reach thermal choke at sea level static for HC-fueled RBCCengine

while it becomes more easily under some flight conditions.Thermal choke with active control was achieved under the flight Mach number 1.2 on the direct-connecting test facilities of NWPU

with the adjustable range up to one quarter of the combustor length.