Performance evaluation of fuel indirect cooling based thermal management system using liquid metal for hydrocarbon-fueled scramjet

Abstract

Hydrocarbon-fueled scramjet is one of the most promising air-breathing propulsion systems for hypersonic flight, but the wall thermal protection issue strictly limits its maximum flight Mach number. This study presents a fuel indirect cooling based thermal management system (TMS) scheme, in which a bypass heat-exchanger connected with closed-Brayton-cycle power generator in parallel for heat source and in series for cold source is applied for the full utilization of fuel's heat absorption capacity. Results obtained by a fuel indirect cooling based TMS coupling model indicate that this TMS has an excellent performance on combustor wall protection, and the highest temperature of combustor wall is no more than 1325.00 K at the heat flux density with maximum value of nearly 5.49 MW/m2. Improving inlet temperature of wall cooling channel (Tlm1) is beneficial to avoid pinch point issue and reduce size for bypass heat-exchanger. In addition, in the view of combustor wall thermal protection, the upper limit of Ma for hydrocarbon-fueled scramjet can reach 9 theoretically, when the fuel indirect cooling based TMS with Tlm1 of 1023 K is employed. This research provides an innovative solution in the wall thermal protection and heat dissipation utilization for hydrocarbon-fueled scramjets at high Mach numbers.