Comparison of External and Sidewall Compression Scramjet Inlet Models

Abstract

The experimental and numerical studies on two different sorts of scramjet inlet models , external and side-wall compression, have been presented in this paper. The experimental investigation was carried out in the hypersonic propulsion test facility (HPTF). The numerical simulations have been done by using the commercial software. The CFD results are agree with the experimental results of the wall pressures , then the CFD is used to evaluate the global performance of the models. The results shown for the same contraction ratio as 4, the external compression inlet has a little bit higher pressure rise at the cowl lip, which is around 7. The external compression inlet has higher mass flow capture ratio up to 93%, but the sidewall compression inlet only has about 70%. The total pressure recovery for the sidewall compression inlet is higher since the external compression inlet has the inherent strong reflection wave at the tip and the separation zone on the opposite surface. The sidewall compression is easer to star t and not so sensitive for off-design conditions. The comparison shows no one has overwhelming advantage. The design of inlet should be under the comprehensive consideration of the whole engine.