Large eddy simulations of complex multicomponent diesel fuels in high temperature and pressure turbulent flows

A multicomponent droplet evaporation model, which discretizes the one-dimensional species and temperature profiles inside a droplet with a finite volume method and treats the liquid phase as thermodynamically real, has been developed and used for large-eddy simulations of high speed diesel sprays in high temperature and pressure closed chambers. Single drop evaporation results obtained by the variable property multicomponent model are shown to match with the constant property model in the limiting conditions. The multicomponent liquid model used together with the Kelvin-Helmholtz - Rayleigh-Taylor droplet breakup model is found to reasonably well predict the experimentally observed non-linear behavior of spray penetration with changing ambient conditions for n-hexadecane and 4 different multicomponent surrogate diesel fuels with 2-8 components. The effects of various modeling assumptions and gas and liquid parameters on the drop and spray evolution and evaporation are investigated in details.