A numerical method for the study of solid-liquid mass transfer in turbulent flows

Paper i proceeding, 2011

A numerical method for the study of high-Schmidt number mass transfer close to solid boundaries is presented. Computational Fluid Dynamics with the Large Eddy Simulations and the dynamic Smagorinsky model for the subgris scale stress tensor were used. Periodic boundary conditions were used to obtain proper boundary conditions for the LES simulation. A fine mesh was used in the bulk of the flow and a extremely fine mesh (y + = 1/40) on a part of the surface where the diffusional flux was evaluated. Model validation shows that the teoretical y + dependences were obtained for the fluctuations paralell to the surface and a somewhat lower y + depencence was obtained for the much smaller perpendicular fluctuation. It is also shown that DNS resolution was obtained in the extremely fine mesh. The usefuleness of the modeling method is exemplified with a simulation of species concentration and by particle tracking the influence of the turbulence on the fluid elements near the walls at y + < 1.