Detailed simulations of bicomponent droplet evaporation

The current work has the purpose to implement a second species in a code, initially designed for the simulation of a pure droplet, in order to handle spherical bi-component droplet evaporation in a turbulent flow. Numerical simulation are then conducted to investigate the details of the physical phenomena. Droplet vaporization is on of the most common instances of multiphase flow with phase change. These phenomena are a key feature in many industrial field such as Rocket Engineering (liquid rocket engine), Mechanical Engineering (gas turbine), Chemical Engineering (industrial furnaces) and occurs frequently in nature (fog, falling rain) as well. We present an Immersed Boundary Method (IBM) for interface resolved numerical simulations of spherical bi-component droplet evaporation in a gas flow. The computation of momentum, energy, and species transport equation in the gas phase is performed by a direct numerical simulation (DNS). Each droplet exchanges these quantities with the gas phase. Therefore, a global balance approach is used in order to realize an accurate and efficient phase coupling without direct solution of the liquids phase fields, saving computational cost. The numerical results have been compared with reference experimental data to evaluate the accuracy of the method. They demonstrate that the implementation is successfully carried out, so the developed IBM code is able to handle bi-component droplet evaporation