Investigation of the self-starting ability of an internal waverider inlet for ramjet

The Internal WaveRider Inlet (IWRI) is a new type of 3D inward turning inlet with rather good performance. It still has a difficulty, no enough good self-starting ability, when IWRI used as a geometry-fixed inlet for ramjets. At first, this research presented a theoretical analysis method of starting ability and self-starting ability for IWRI, to prove that the IWRI applied in ramjet was facing more difficult challenges of self-starting ability than scramjet. The self-starting ability should be considered in the process of designing ramjet inlet. Then, effects of bleeding mechanism on geometry-fixed ramjet IWRI was investigated by flow numerical simulation, and numerical results shown that IWRI’s self-starting ability at low Mach numbers was improved obviously: lowest Mach number of self-starting was decreased from 3.8 to 3.2, which also can endure the greater compression ratio of 32 than 28 with no bleeding. Two different groups of bleeding positions indicated that bleeding before throat section has no effect on the self-starting ability of IWRI.