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

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. © 2022, Science Press. All right reserved.