Droplet breakup and coalescence characteristics of hollow cone spray in crossflow

A numerical investigation is done to study the influence of droplet collisions on the characteristics of hollow cone sprays when subjected to a crossflowing stream of air. The process of hollow cone spray in crossflow is simulated using Eulerian-Lagrangian point parcel spray solver in OpenFOAM platform. Droplet atomization is modelled using LISA-TAB atomization model, and the droplet collisions are accounted using the standard O'Rourke collision algorithm. The numerical simulations are performed to study the effect of crossflow velocity on the hollow cone spray by varying the liquid to gas momentum flux ratio in the range 17,435-213,587. Qualitative and quantitative comparison is made between the spray with collision model and without collision model. The spray characteristics such as Sauter mean diameter (SMD), maximum droplet diameter and length of penetration are reported in the current study. A significant difference in the SMD is observed between the spray with and without collision model. For all the crossflow velocity cases studied, the droplet dispersion is observed to be higher for spray with droplet collisions accounted compared to the spray without accounting collision interactions.