SABRE空气预冷器流动与换热数值研究

Numerical study on flow and heat transfer of air precooler in SABRE

为了掌握吸气式火箭发动机(SABRE)空气预冷器的流动换热特性,为设计相应类型的预冷器提供技术基础,针对SABRE预冷器最小周期性单元,以数值方法研究了管间距、管排数、空气入射角度及氦气/空气热容量比对预冷器流动换热的影响。研究结果表明:增大管排数和减小管间距,能够增大预冷器换热功率,降低空气出口温度,但会降低空气侧、氦气侧平均换热系数,减弱对流换热能力,增大空气侧总压损失。空气入射角度对空气侧、氦气侧换热影响微小,但对空气侧总压恢复系数影响显著。增大氦气/空气热容量比能够降低空气侧总压损失,增大空气侧、氦气侧平均换热系数,降低空气出口温度。

In order to study the flow and heat transfer characteristics of air precooler in Synergistic Air-Breathing Rocket Engine(SABRE)and provide the technical basis for designing precooler, the effects of tube pitch, tube row, air incidence angle and helium/air heat capacity ratio on the flow and heat transfer of air precooler were numerically studied.The results show that increasing the number of tube rows and reducing the tube spacing can increase the heat transfer power of the precooler and reduce the air outlet temperature.However, they also reduce the average heat transfer coefficient on the air side and helium side, weaken the convective heat transfer coefficient and increase the total pressure loss coefficient of air side.The air incidence angle has little effect on the heat transfer of both sides, but has a significant effect on the total pressure recovery coefficient of air side.Increasing the helium/air heat capacity ratio can reduce the total pressure loss coefficient on the air side, increase the average heat transfer coefficient on both sides, reduce the air outlet temperature and enhance the pre-cooling effect.