复合型微细通道换热器的流动传热特性研究

As one of the key components in the hypersonic precooling engine, the precooler should reduce the temperature of hot air in a very short time, and its flow and heat transfer performance has an important impact on the performance of the precooled engine. In this paper, a new type of hybrid printed circuit heat exchanger is proposed in view of the large differences in the two-side mass flow rates and working pressures in the precooler. The numerical results show that along the flow direction of low-temperature helium, the temperature and convective heat transfer coefficient of low-temperature helium and high-temperature air increase gradually, and the change after Z=130 mm is obviously greater than the previous change. Increasing the mass flow on the air side increases the pressure loss on the air and helium sides. However, increasing the helium-side mass flow reduces the air-side pressure drops. The heat transfer rate per unit volume increases with the increase of the mass flow on both sides.