Numerical Simulation of a Droplet Break-up phenomenon in Cross Flow of Cold and Hot Gas and its Dynamic investigation in Three-Dimensional Field

In the present paper, the simulation of droplet dynamics and its breakup process in the cross flow of cold and hot gases are performed. Herein, the Navier-Stokes equations are used with employing two additional equations for tracking the liquid-gas interface and for computing the mass transfer due to the evaporation and condensation. Accuracy of the applied numerical algorithm is evaluated by simulation of the Stefan heat transfer problem, two-phase laminar Couette flow, and comparison of the present numerical results with those obtained based on the analytical solution. The dynamics of a droplet break-up in the cold gas are studied and the obtained results are discussed. Then, the study is carried out for the simulation of droplet dynamics in the cross flow of hot gas and the effect of the evaporation on the break-up process is investigated. The present study shows that the aerodynamics forces and Rayleigh-Taylor and Kelvin-Helmholtz instabilities have dominant effects on the droplet dynamics in the cold gas. However, for a droplet in the cross-flow of hot gas, evaporation has a significant effect on the deformation and breakup phenomenon.