Quasi-steady load-following thermal management and power generation for hypersonic vehicle RBCC engines via a helium-xenon closed Brayton cycle

Abstract

Rocket-based combined cycle (RBCC) engines operating across a wide Mach-number range (Ma 4-8) face dual challenges of severe aerodynamic heating and high onboard power demand. Conventional hydrocarbon-fuel cooling is limited by the coking-temperature threshold, while near-critical supercritical CO2 cycles may encounter strong property variation and control difficulty near the pseudo-critical region. This paper numerically assesses an integrated third-fluid cooling and power-generation concept using a binary helium-xenon (He-Xe) mixture. A coupled system-level model, linking RBCC internal ballistics, temperature-dependent mixture properties, an Eckert reference-enthalpy heat-transfer model, and closed Brayton-cycle thermodynamics, is established to evaluate cooling and shaft-power trends. Submodel-level verification checks are added for mixture properties, cooling-channel heat transfer and pressure loss, and the Brayton-cycle power boundary.