带扩张段构型超声速气流中横向射流数值模拟

针对带扩张段构型的发动机燃烧室,采用欧拉-拉格朗日仿真方法研究喷注方式、喷孔参数及隔离段燃烧室构型的改变对于射流雾化效果的影响,用以更好地指导发动机设计.结果表明,在保证发动机总体流量不变的条件下,喷孔孔径减小或者喷孔总数量减少使得液气动量通量比增大,有利于同时增大单孔射流穿透深度以及液滴展向宽度.贫燃工况下如当量比为0.7条件下,射流流量减小,混合效果可能变差.而在发动机结构设计方面,隔离段到燃烧室的过渡设计不宜采用大转角,15°转角是相对较为理想的设计方案.采用小角度突扩构型设计比渐扩构型更容易找到相对好的点火位置.

Numerical Simulation of Transverse Liquid Jet in Supersonic Flow in the Expanded Section Configuration

The Euler-Lagrange simulation method was used to study the jet atomization effect for the engine combustor with expanded section configuration.In the course of the study,the injection mode,the parameters of the injection hole and the configuration of the combustion chamber in the isolation section were changed.The conclusion can be used to guide the engine design better.The results show that under the constant overall flow of the engine,the reduction of the orifice diameter or the total number of orifices leads to a larger hydro-pneumatic flux ratio,which is conducive to increasing both the single-hole jet penetration depth and the droplet spread width.Under lean combustion conditions such as the equivalent ratio of 0.7,the jet flow rate decreases,and the mixing effect may become worse.In the aspect of engine structure design,the transition design from isolation section to combustion chamber should not adopt a large turning angle,and 15°is relatively ideal.It is easier to find a better ignition initiation position for small angle sudden expansion than for gradual expansion.