Turbine Based Combined Cycle Inlet Mode Transition at Different Operation Conditions

摘要

Smooth transition from turbojet to ramjet mode is critical to turbine based combined cycle (TBCC) propulsion system. The mode transition fluid dynamics and the performance of the tandem configuration inlet operating at different conditions were investigated through wind tunnel tests. When the inlet operated at supercritical and critical conditions, the terminal shock was unsteady and oscillated in the throat and the shoulder of the inlet, respectively. When the inlet operated at subcritical condition, the shock stayed steady in front of the cowl leading edge. During the mode transition, the mass flow ratio and Mach number increased in the aerodynamic interface plane of high speed flowpath and decreased in the low speed flowpath at different operation conditions. The total pressure distortion index DCM was not sensitive to the different operation conditions, but composite distortion index Jf'and total pressure recovery a were sensitive to the operation of the inlet The results obtained in this paper can help us realize fluid dynamics and the performance of the tandem configuration inlet during mode transition and provide some suggestions for smooth inlet mode transition.