适用于内燃机喷雾的改进液滴碰撞结果划分准则

Improved Classification Criterion of Droplet Collision Outcomes for Internal Combustion Engine Spray

本文主要对液滴碰撞领域的反弹/聚合准则进行了改进,并从理论角度分析了Ashgriz和Poo建立的反溅分离/聚合准则的局限性,进而修正了由Munnannur和Reitz提出的拉伸分离/反溅分离重合区域划分准则。结合此前改进的拉伸分离/聚合准则与Gotaas等人建立的反溅分离/聚合准则,最终建立了一套较为完整的适用于内燃机喷雾领域的、考虑内燃机缸内气相特性及不同燃油液滴物性等条件的液滴碰撞结果划分准则,并基于液滴碰撞实验及本文喷雾对撞实验,对改进准则进行了验证。

The bounce/coalescence criterion of droplet collision is improved in this paper. From a theoretical perspective, the limitations of the stretching separation/reflexive separation criterion established by Ashgriz and Poo are analyzed, and then the overlapping region classification criterion of stretching separation/reflexive separation proposed by Munnannur and Reitz is modified. Combined with the previously improved stretching separation/coalescence criterion and the reflexive separation/coalescence criterion established by Gotaas et al, a set of relatively complete criteria for droplet collision outcome, which are suitable for the internal combustion engine spray, considering the ambient gas phase characteristics and the physical properties of fuel droplets, are finally established.Based on the experiments of droplet collision and the spray impingement, the improved criteria are verified.