A numerical study on the interaction of droplet collisions and air flow impact in cross-impinging spray

The spray impingement method has been widely used to effectively achieve better atomization of liquid fuel. The factors influencing the formation of impinged spray are analysed using computational fluid dynamics (CFD) modelling. Free spray and impinging sprays with three impinging distances are simulated using the Eulerian-Lagrangian multiphase method. The results are validated with experimental data. Meanwhile, some advanced methods are employed to obtain better results of simulation such as the AMR technique and adaptive collision mesh method. The spray widths in different impingement distances are compared to analyse the distribution of spray droplets. Upon the binary collision theory, the distribution of discrete droplets is attributed to the collisions of huge amounts of particles. In the process of spray impingement, the impact of air flow, generated by gas entrainment of spray, also influences the spray. As a supplement to the collisions of discrete droplets, the impingement of continuous air flow and their interaction is mainly discussed. The impact waves observed in the flow field demonstrate that the impingement of entrained air flow is similar to jet impingement.