A novel inlet boundary condition for VOF-DNS simulations of the primary breakup of prefilming airblast atomizers

Abstract

[EN] Prefilming airblast atomizers are becoming widely used in state-of-the-art aero engines. The planar configuration experimentally studied by the Karlsruhe Institute of Technology (KIT) has been computationally replicated by different research groups through both Large Eddy Simulation (LES) and Direct Numerical Simulation (DNS). The present investigation reports the use of a novel inlet boundary condition for the DNS study of prefilming airblast atomization that allows accounting not only for the inflow turbulence but also for the temporal evolution of the liquid film thickness at the DNS inlet. The methodology implies the resolution of subsequent singlephase LES, two-phase flow LES and two-phase flow DNS. The former simulations are solved by using the interFoam solver from the OpenFoam toolbox, whereas the latter is computed with the PARIS open-source code. Results for a widely known operating condition show a different degree of atomization when the liquid film thickness evolution is accounted for than the one obtained through the use of a constant liquid film thickness at the domain inlet.