The design and validation of over/under turbine-based combined cycle inlet

The design constraints including capture area and mode transition point of turbine-based combined cycle (TBCC) inlet are determined by the performance analysis of combined cycle propulsion system. According to the mass flow and thrust requirement of the combined cycle engine, the capture area of 1.0 m2 and mode transition between Ma 2.2 and 2.5 are recommended. Based on these two quantities an over/under TBCC inlet which can operate from takeoff to Ma 4.0 is designed. The variable geometry scheme of TBCC inlet is shown at different flight Mach number. Three dimensional numerical simulations of full-scale model and wind tunnel test of 8-percent scale model are explored to verify this inlet design method. The results from the numerical simulations and experimental tests indicate that the TBCC inlet could work properly during this Mach number range. The mass flow captured by the inlet and total pressure recovery at turbine/ramjet aerodynamic interface planes (AIP) meet the requirement of the TBCC propulsion system.