A Grid-Free Method for LES of Incompressible Flow

A grid-free method for the LES of turbulent incompressible flow is presented. The computational engine is based on the Lagrangian Vortex Element Method to account for the dynamics of the resolved vorticity field and the Vorticity Redistribution Method (VRM) to account for turbulent diffusion. Turbulence is modeled here using the standard Smagorinsky subgrid-scale model but work is underway to implement a dynamic version. In this paper, the accuracy and convergence rate of VRM are presented for the case of diffusion with variable viscosity. Furthermore, the adaptivity as well as the robustness of the proposed method in capturing large-scale vortex structures typical of vortex dominated turbulent flow are demonstrated using preliminary results from the LES of the collision of a pair of coaxial vortex rings, perturbed initially by the wave-number of their most unstable mode.