Analysis of Flows in Scramjet Isolator Combined with Hypersonic Inlet

Abstract

Cheng-Peng Wang * Kun-Yuan Zhang† Jian-Jun Yang‡ Dept of Power Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China Abstract The experimental and numerical investigation of flow in isolator of hypersonic sidewall compression inlet was made under Mach 5.3/3.85. The rectangular area isolator with S/H =8 was designed according to Waltrup’s empirical theory. Static pressure distributions at the isolator upper and lower wall, pitot-pressure distributions at the isolator entrance and exit, were obtained. Results from a numerical investigation of a shock wave/turbulent boundary-layer interaction in isolator are compared to wall static pressure values obtained from the experiment. The turbulence models are the two-equation RNG k-e model, which is able to capture the major features of the flow with shock/boundary-layer interaction and separation. A characteristic feature is the presence of the asymmetric distribution of boundary layer at isolator entrance and the strong cowl shock, which induces significant nonuniform flowfield at the isolator exit and in the isolator. The serious flow nonuniformity leads to the drop of the maximum pressure ratio obtained in the isolator and the existence of subsonic region at the 2/3 height of the isolator exit section. The computed results indicate that the Waltrup’s empirical theory was suitable for initial design of scramjet isolator. Nomenclature H = isolator height, mm S = isolator length, mm x = streamwise coordinate