喷注角度对超声速气流中液体横向射流的影响

Effects of Injection Angles on Liquid Jets in Supersonic Crossflows

关键词:  超声速气流  喷注角度  液体射流  扩张型面  高速摄影  欧拉-拉格朗日方法

Key words:  Supersonic flow  Injection angle  Liquid jet  Expansion channel  High-speed photography  Eulerian-Lagrangian method

摘要:

为探索超声速气流中变角度组合射流对喷注雾化过程的影响，采用高速摄影和基于KH-RT破碎模型的欧拉-拉格朗日数值仿真方法开展研究，仿真结果和实验吻合较好。研究表明，同一流量下逆流喷注，可以较为有效地增强混合效果，提升射流穿透深度。带扩张型面内液雾穿透深度呈现先增大后降低的趋势。等流量条件下顺流双孔喷注有效截面面积大体一致，略低于单孔直喷。等效流量下逆流喷注所得液雾截面面积收益最为明显。截面平均粒径方面，单孔喷注雾化粒径基本一致，顺流双孔喷雾粒径较小。等压降顺流对喷由于流量较大，雾化质量相对较差，平均粒径最大。

Abstract:

High-speed photography and Euler-Lagrangian numerical method based on KH-RT breakup model were used to study the effects of combined jets with variable angles on spray atomization process in supersonic flow. The simulation results are in good agreement with the experimental results. According to the research results， with a constant total mass flow rate of liquid sprays， when the jet is injected countercurrent， the mixing effect is enhanced and the spray penetrates higher. It is found that the penetration depth of jet spray in a rectangular channel with an expanded section increases first and then decreases. At the same flow rate， the cross-sectional spray area of combined double injections is almost the same， which is slightly lower than single injection. Under the equivalent flow rate， the cross-sectional spray area gain of the counter-flow injection is the most obvious. In addition， in terms of the average particle size of the cross-section， the particle size of single jet with different angles is basically the same and the combined double jets is smaller. Because of the large flow rate， the atomization quality of impinging jets with fixed pressure drop is relatively poor and the average particle size is the largest.