Performance assessment of a closed-recuperative-Brayton-cycle based integrated system for power generation and engine cooling of hypersonic vehicle

Hypersonic vehicle is a next generation aircraft/spacecraft with broad applications, but its development is limited by the high-power electricity supply and thermal protection of engine. This study presents an integrated system based on Closed-Recuperative-Brayton-Cycle (CRBC) for power generation and engine cooling, in which combustion heat dissipation is transferred by liquid metal and partly converted into electric power. An integrated system model which consists of a scramjet combustor, wall cooling channels and a CRBC power generator, is established to evaluate system performance. Results indicate that the integrated system can meet the demands of both high power generation and engine thermal protection for hypersonic vehicles. There is an optimal temperature of liquid metal at heater inlet for power generation performance. The peak electric power increases with fuel equivalence ratio. Liquid sodium exhibits excellent heat transfer performance for engine cooling, the mass flowrate of which becomes greater with smaller fuel equivalence ratio. Besides, the influence of power generation on propulsion is not significant. The specific impulse and specific thrust have maximum decrease of about 2% compared to the cases without heat dissipation. This research provides a novel scheme to achieve power generation and engine thermal protection for hypersonic vehicles.