Assessing the feasibility of bypassing spray models in high-speed liquid jet atomization

The main goal of most simulations of atomizing liquid jets is predicting the resulting vapor field. This requires accurately capturing primary breakup of the jet core and subsequent transport, breakup, and evaporation of the spray of drops. In this talk, in the context of a sub-sonic jet of liquid surrounded by a supersonic co-flow of gas, we address the following question: Considering the high velocities and resulting rapid aerobreakup of drops to much smaller daughter drops, can we bypass expensive Lagrangian/Eulerian semi-empirical spray models and directly convert a drop undergoing breakup to vapor? We perform comprehensive scaling analysis and multiple one-way coupled Euler-Lagrangian simulations for prescribed turbulent velocity fields to quantify the errors in the prediction of the vapor field if a drop undergoing breakup is directly converted to gas instead of modeling the evolution of the spray of drops post-breakup. We demonstrate that modeling spray particles after breakup may be bypassed for high enough Weber numbers, corresponding to high velocity magnitudes for the gaseous jet, leading to a massive reduction in computational cost and straightforward load balancing.