A NEW MODEL FOR SURFACE TENSION FORCE INTURBULENT INTERFACIAL FLOWS

Here we presented a new model for mean surface tension force. A set of equations for the description of the turbulent interfacial flows, based on the Reynolds Averaged Navier-Stokes (RANS) equations for two fluids with interfaces, is used. By time averaging of the surface tension force relation which is part of the Navier-Stokes equations, the mean fluctuation correlations of the curvature and surface normal vector is appeared in the equations and it is predicted that it plays an important role in the interface topology. To overcome the closure problem, we need to model such extra terms. In addition to model such correlation, the mean curvature and mean surface normal vector must be modeled. It is because they are obtained from nonlinear relations which are related to the interface shape. Here, we propose some new models for the unknown terms described above and examined them by simulating some practical problems using a computer code. For simplicity, we only consider the two-dimensional, time dependent cases. For capturing the interface we use the VOF (Volume Of Fluid) method. The code for examining the models is SURFUR code (open source). We use the code to simulate the turbulent flow around droplets. Here the effect of the new model on the topology of the interface is studied and effects of the inclusion of the new models in the equations are studied.

A NEW MODEL FOR SURFACE TENSION FORCE INTURBULENT INTERFACIAL FLOWS Keywords:

Turbulence , Interfacial Flow , Surface Tension Force , VOF Method