A study on droplet group evaporation modeling based on interface resolved numerical simulations of two-phase flow

Abstract

Large-scale numerical analyses of the evaporation of groups of 640 droplets and 2,964 droplets were conducted by the interface-resolved simulation method, and the effect of mutual droplet interference on the evaporation rate of droplets in groups was modeled. The interference effect reduces the evaporation rate of each droplet due to the increase in its surrounding fuel concentration caused by the evaporation of neighboring droplets. The evaporation rate interference coefficient, which is the ratio of the evaporation coefficient of each droplet in a group to that of a single droplet without interference, was modeled using three parameters: the distance between the droplets, the size of the droplet interfering with an object droplet, and the evaporation state of the interfering droplet. A new droplet evaporation rate parameter containing these model parameters was proposed, and it was confirmed that the proposed parameter properly models the evaporation rate interference coefficient calculated using the droplet group evaporation numerical analysis results. In addition, the accuracy of the model was improved by including a further parameter to express the positional relationship of a droplet within a group.