A mixed primary atomization model with quantification of aerodynamic, turbulence and cavitation effects

Abstract

Spray atomization has a key impact on the combustion and emission performances of the engines. It involves a highly dynamic two-phase flow process consisting of two distinct stages: primary and secondary breakup. Due to their distinct physical characteristics, it is essential to model these processes separately using different numerical approaches within the spray breakup model. This study focuses on investigating the collective influence of aerodynamic force, cavitation, and turbulent fluctuations on primary breakup. To enhance the accuracy of spray simulations, a mixed primary atomization (MPA) model is proposed by integrating the Wu-Faeth theory along with the classical KH-RT model and the Sarre cavitation model. By comparing simulation results of both macroscopic and microscopic spray characteristics with experimental data under various conditions, the efficacy of the developed MPA model is validated. The sensitivity analyses of specific model parameters and the examination of the contribution ratios of different sub-models under various conditions enhance our understanding of the model calibration. Additionally, considering the complexity of near-nozzle sprays influenced by turbulent flows, cavitation, and interactions with the surrounding gas, a comparative analysis of the classical KH-RT model and the MPA model is conducted based on simulation results, specifically focusing on near-nozzle spray characteristics.