Cooperative optimization of thermal management performance and power generation performance for novel ultra-high temperature airborne power generation system on hypersonic vehicles

To simultaneously meet the requirements of thermal protection and energy supply, this paper proposed a novel ultra-high temperature airborne power generation (APG) layout for hypersonic vehicles using CO₂-SO₂ as the working medium. A quasi-one-dimensional model and solution scheme coupling the scramjet combustor, ceramic matrix composite (CMC) regenerative cooling structure, and considering fuel cracking in closed Brayton cycle (CBC) were presented. The feasibility and control mechanism of the novel layout from the perspective of thermal management and power generation were evaluated. Results indicate that the ultra-high temperature layout can balance efficient thermal management and high-power power generation under finite cold source. λ_CMC will play a key regulatory role in the operation process. As the λ_CMC increases, the extreme thermal environment and finite cold source conditions will be alleviated, and the overall output power level will significantly increase. However, the λ_CMC should neither be too high nor too low, with a recommended value of 100 W/(m·K). Additionally, the heat transfer capacity on both sides of the regenerative cooling structure will limit the power level increase. Appropriately extending the combustor length can theoretically delay this phenomenon, but the actual optimization effect is not satisfactory. It is not recommended for application in engineering practice.