歧管式通道内碳氢燃料超临界压力流动换热的数值模拟研究

Numerical simulations have been carried out for the flow and heat transfer of hydrocarbon fuel in the MMC cooling panels at a supercritical pressure. Effects of MMC unit numbers on the flow and heat transfer characteristics are investigated. Results indicate that compared with the parallel cooling channel, the heat transfer can be enhanced in the MMC and the heat transfer efficiency increases with the increase of MMC unit number. The average heated wall temperature of the MMC can be reduced up to 150 K and the heat transfer coefficient can be increased up to 50% comparing to the parallel cooling channel under current test conditions. This attributes to the flow reorganization effect and impact jet flow phenomenon caused by the presence of the MMC structure, which greatly enhances local fuel flow and favors the turbulence generation. Although the pressure loss is increased in the MMC channel, the magnitude of the pressure loss is less than 1.1% of that in the cooling system, whose effect can be safely omitted during the practical application of the MMC cooling structure. The results obtained here will lay a good foundation for the design of advanced regenerative cooling channels.