Durable Pre-cooling Heat Exchangers for High Mach Flight

Air breathing propulsion systems provide greater propulsion efficiency than rocket based systems. Of the air breathing technologies, turbine based systems provide the flight speed flexibility to propel the vehicle from takeoff to approximately Mach 4. However, at flight speeds above Mach 2, the stagnation temperature of the air at the vehicle inlet reduces the inlet mass flow rate and achievable pressure ratios of turbine based propulsion systems. To extend the range of flight speed of turbine based engines beyond Mach 2 and achieve the Mach 4 capabilities, the inlet air must be precooled to less than 260C. Hence, there is a need to develop pre-cooler heat exchangers which enable the operation of turbomachinery and provide thrust from takeoff to approximately Mach 4.Under this Phase II SBIR, ACT proposes to continue the development of its novel pre-cooler that will extend the operational range of turbojets to flight speeds up to Mach 4, which will enable a scramjet to take over and provide hypersonic cruise in a Turbine Based Combined Cycle (TBCC) vehicle. The effort builds on the successful proof-of-concept results from Phase I. Phase II effort, will mature the pre-cooler technology for heat transfer efficiency, structural robustness, manufacturability and durability.