超声速气流中液体横向射流组合喷注特性实验

以液态燃料为动力的超燃冲压发动机中,液体横向射流在超声速气流中的喷注、混合和雾化特性直接影响了超燃冲压发动机燃烧室的工作效率。提出一种基于高速摄影的图像处理方法,此方法能消除图像处理过程中的人为因素干扰,得到唯一、定量的射流振荡的边界信息;提出一种基于粒子图像测速法的射流展向扩展边界获取方法,能得到射流破碎后形成液滴所能达到的最远距离;基于以上两种图像处理方法和对比实验研究了单孔喷注、展向组合和沿流向组合的喷注方式对射流穿透深度、展向扩展和激波角的影响,结果表明:相比单孔喷注方式,展向组合和沿流向组合的喷注方式均能增大射流的穿透深度,且能增大射流的展向扩展角和展向扩展范围;随着沿流向布置的喷孔间距的增大,射流的穿透深度增大。

Experimental Investigation on Injection Characteristics of Assembled Transverse Injectors in Supersonic Crossflow

The injection, mixing and atomization characteristics of transverse liquid jet in liquid-fueled scramjet are the determining factors for the efficiency of the combustion chamber. An origin image analysis method, without any threshold choosing section, was developed in house to get the unique unstable boundary of the transverse jet without any manual effects. The lateral extension boundary capturing method, which is based on PIV technique and the corresponding image analysis method, was developed to illustrate the lateral outer boundary of the jets. Results from targeted and comparative experiments indicate that: compared with the single jet case, the penetration heights and lateral extension get larger in the assemble jets cases. A larger distance between the streamwise assembled double injectors contributes to a higher penetration height of the jet.