Influence of Stokes Number on Collisional Interfacial Area Production Terms within the Σ-Y Eulerian Spray Atomization Model

Abstract

[EN] The present study shows the effects of Stokes number on the modeling of collisional interfacial area production terms within the Σ-Y model. This model can be employed for CFD simulations of high Weber and Reynolds number sprays using a RANS turbulence modeling. Within the model production of interfacial area is assumed to result from turbulent stretching and turbulent droplet collisions. The modeling of collisional processes requires the calculation of a characteristic turbulent collision velocity. In the present work this velocity was determined under consideration of Stokes number effects leading to turbulent droplet velocity fluctuations attenuated with respect to the gas phase fluctuations and including partial correlation between the velocities. The influence of this new modeling approach is tested within a 2D spray simulation by comparing the Sauter mean diameters observed to the ones obtained by employing the modeling approaches proposed in the literature which do not consider any Stokes number effects. The reduced collision velocites in the new modeling lead to higher values for Sauter mean diameters in the spray.