Numerical simulation of droplet evaporation using interface tracking methods: phase change modelling

The present work gives a description and comparison of recent methods for the direct numerical simulation of droplet vaporization using a two-scalar approach for energy and species equations. Those methods require a choice of modelling for the phase change process. The comparison relies on the work of Palmore at al. in the context of Volume of fluid and on the phase change procedure of Rueda Villegas et al. [2] in the Level set framework. Both approaches have been implemented and coupled to the same two-phase low Mach solver. A quantitative analysis is given on the canonical Stefan flow problem where analytical solutions are available. First the 1D planar Stefan problem is performed to avoid any errors associated to topology. Then, the 3D spherical Stefan problem is tested to evaluate both methodologies on a multidimensional case where the choice of interface representation is prevalent. Finally, a 2D droplet convected in a quiescent ambient gas is presented. This last test case aims to demon- strate robustness of the solver on a more demanding test case implying convection, interface deformation and non homogeneous vaporization.