光腔与扩压器的一体化优化数值模拟

Integrative optimization numerical simulation of cavity and diffuser

采用数值模拟方法对化学氧碘化学激光器光腔通道、超声速扩压器一体化方案的优化展开研究,对扩压器的角度、构型、背压等参数对扩压性能的影响以及对光腔内流场的影响进行计算和分析。研究结果表明:传统的直接扩散型以及平直段+扩散段型的超声速扩压器,抵抗背压影响的能力较弱,且光腔出口处静压急剧升高,影响了光腔内的流场;通过在平直段+扩散段型的超声速扩压器的平直段部分,插入数片楔形体,可以将扩压器的工作背压提升33%以上,且可以有效地隔绝扩压器对光腔内流场的不利影响,从而使光腔下游的逆压梯度大大降低;同时,由于缩短了扩压器的长度,扩压器的总压损失明显降低,冷流状态下的总压恢复系数达到0.484。

The performance of supersonic diffuser downstream the cavity in chemical oxygen-iodine laser pressure recovery system can obviously influence the flow field quality in cavity,and it＇s static pressure recover and total pressure loose performance can determine the pressure recovery system size downstream the diffuser.This paper uses the numerical simulation method to research the influence of supersonic diffuser design parameter such as diffuser angle and diffuser outline and back pressure and so on.The study shows that,the static pressure ratio was increased about 33% and the total pressure recover coefficient was increased to 0.484 by means of adding a constant section with wedges between the cavity and the supersonic diffuser.At the same time,the flow filed quality such as static pressure and Mach number distribution in cavity was obviously improved.