Dynamic characteristics of the sCO<sub>2</sub> recompression Brayton cycle for aerodynamic heat recovery of long-duration high-speed aircraft

<p indent="0mm">Aerodynamic heat protection and the efficient recovery and utilization of thermal energy represent significant challenges for long-duration, high-speed flight vehicles. This study introduces a novel approach utilizing a supercritical carbon dioxide (sCO₂) Brayton cycle to recover and harness aerodynamic heat, thereby achieving dual objectives of thermal protection and power generation. A dynamic thermal-to-work conversion model of the sCO₂ Brayton cycle for aerodynamic heat recovery has been developed. The system’s dynamic operational characteristics and the interactions among key components are evaluated using metrics such as temperature, pressure, thermal efficiency, and net power output. Research findings indicate that the sCO₂ Brayton cycle system holds considerable promise for engineering applications in high-speed aircraft aerodynamic heat recovery. Under varying aerodynamic heat flux conditions, the cycle exhibits nonlinear dynamic behavior and overshoot phenomena. Increasing the temperature difference in the regenerator’s heat exchange process can effectively mitigate the system’s thermal inertia.