Effects of wall cooling on performance parameters of hypersonic inlets

The internal flowfield of a 2-D mixed-compression hypersonic inlet was simulated numerically at different wall temperatures. The effects of wall cooling on performance parameters of the hypersonic inlet without and with the backpressure, and especially on the maximum backpressure of a fixed-geometry hypersonic inlet were discussed. The inner physical mechanism of wall cooling improving the maximum backpressure of hypersonic inlets was analyzed. In contrast with no wall cooling, the static pressure ratio of hypersonic inlets without backpressure is reduced slightly, but the mass-captured coefficient, total-pressure recovery coefficient and the flow uniformity of hypersonic inlets at the isolator exit are improved by the action of wall cooling. The interaction between boundary layers and shocks is weakened due to wall cooling, which leads to that the boundary layers separations at the entrance of the isolator caused by the high backpressure occur later, and it can improve the maximum backpressure ratio of hypersonic inlets. With the wall temperatures decreasing, the maximum backpressure ratio and mass-captured coefficient are added, and the total-pressure recovery coefficient of hypersonic inlets is reduced.