Numerical investigation of evaporating isopropyl alcohol spray with LES-FDF model

A model based on the framework of possibility density function (PDF) was used to simulate the sub-grid scale eddies “seen” by the droplets in an evaporating isopropyl alcohol spray. LES was used to simulate the fluid flow. The motion and evaporation of the droplets were solved in Lagrangian method and the filtered density function (FDF) transport equation was adopted to solve the sub-grid scale velocity of the gas phase surrounding the droplets. The comparison between the numerical and experimental results shows that the LES-FDF model can distinctly improve the precision of the simulation by considering the influence of sub-grid turbulence on the motion and evaporation of the droplets. Further studies on the effects of pressure and temperature on the droplet evaporation in turbulence were also carried out.