气动塞式喷管的流场数值模拟和设计参数探讨

Numerical Simulation and Design for Aerospike Nozzle

针对气动塞式喷管流场中存在的激波、激波与附面层相互作用、大尺度分离流动等复杂的物理现象 ,本文采用扩展的压强校正法求解用紊流模型封闭的可压缩湍流平均 N-S方程组 ,利用交错网格系统抹平迭代过程中的数值振荡 ,并通过高分辨率的 TVD格式进一步改善压强校正法的激波捕获效果 ,对气动塞式喷管的流场进行了详细的数值模拟。并进一步探讨了喷管倾角、塞锥长度和二次流流量比对喷管流场结构和性能的影响。

Aerospike nozzle engines are considered as a candidate for the next generation of propulsion system for reusable launch vehicles because of the possibility of improving performance.In order to provide an insight into performance and to control flow field development of plug nozzles,numerical optimization of truncated plug nozzles was performed by solving the Navier Stokes equations.Parameters investigated included spike length,pitch angle and secondary flow rate.Results indicated that significant performance gains result from the external freestream expansion,which self adapts to external pressure variation,as well as the short compact design for high expansion ratios.The expansion waves,compression shocks and the separated base flow dominate the flow structures and affect the aerospike nozzle rocket engine performance.Secondary flow may eliminate the recirculating base flow region and better performance will be obtained.