A conjugate numerical model for the thermal analysis of the regenerative cooling of an X-51A-like aircraft

Abstract

A conjugated computational fluid dynamics model using convective thermal boundaries is proposed for the thermal analysis of the regenerative cooling system of an X-51A-like hypersonic aircraft in conditions closer to realistic scenarios. By X-51A-like, we mean that the convective boundaries of the cooling system are determined according to the structure and flight conditions (Mach 6 and an altitude of 20 km) of the X-51A Waverider. The aerodynamic heating, supersonic combustion, and convective heat transfer with an interior (fuel tank) are simulated from an engineering perspective. The flow, heat transfer, and pyrolysis characteristics of endothermic hydrocarbon fuels (EHFs) flowing in B-channels (bottom), S-channels (side), and T-channels (top) considering buoyancy effect are simulated and compared. A distinct temperature distribution difference in the solid region is observed between the cases with different boundary conditions. However, the cooling performance of EHFs is insensitive to the type of thermal boundary. Five indices, the maximum temperature, outlet temperature, n-decane conversion, total heat sink, and pressure drop, are compared to comprehensively assess the cooling performance. The cooling demands in the B-channels and S-channels are about 1.3 times those in the T-channels because of the additional cooling effect from the adjacent fuel tank. This study should be of great significance in the practical and systematic design of regenerative cooling systems.