Assessment of a novel system coupling steam reforming with solid oxide fuel cell for synergistically enhancing thermal protection and power generation in hypersonic vehicles

To address scramjet thermal protection and power generation, an architecture coupling steam reforming (SR) with a solid oxide fuel cell (SOFC) is proposed. Endothermic SR of hydrocarbon fuel in the wall cooling channel cools the scramjet while producing hydrogen for the SOFC, whose exhaust sustains SR. Multi-dimensional models are established to predict chemically non-equilibrium flows and electrochemical characteristics. The results indicate that, compared with conventional regenerative cooling, the proposed architecture elevates the fuel’s chemical heat sink proportion from 21.4% to 78.6%, reduces the engine peak wall temperature by 36.54%, and raises the maximum allowable wall heat flux by 165.17%, extending the safe envelope of the scramjet. Furthermore, the system achieves 50.92–55.70% thermoelectric efficiency, outperforming existing technologies. Moreover, underlying degradation mechanisms are clarified, highlighting the need for synergistic flow-reaction regulation. Finally, parametric analyses delineate the optimal design windows for the cooling channel aspect ratio and the SOFC fuel utilization ratio.