Aerodynamic performance analysis of a hypersonic inlet isolator using computation and experiment

A two-dimensional mixed compression inlet model with a subsequent isolator section is tested under Mach 4 and 5 flight conditions. Different configurations of the isolator are assessed with respect to their compression efficiency. The experimental investigations yield schlieren pictures of the isolator flow and static surface pressure measurements. The numerical simulations are performed with a Reynolds-averaged Navier-Stokes solver using a k-omega turbulence model, especially,extended for modeling high-speed wall-bounded flows and separation regions. The close collaboration of experiment and simulation is beneficial: Validation of the simulation is achieved by the test data and the flowfield information available in the computational fluid dynamics results is employed to interpret the experimental findings and to compute the performance parameters. The computed static pressure ratios are in excellent agreement with empirical predictions. Furthermore, the investigations show that increasing the isolator length reduces the pressure sensitivity of the inlet. However, the experimental tests show that above a certain isolator length, no further increase of the sustainable backpressure is possible.