VπLES- hybrid vortex and grid based method for simulation of turbulent flows at high Re numbers

The paper presents development and validation of a new computational fluid dynamics (CFD) method using a combination of grid-free (Vortex Particle Method, VPM) and grid-based (Finite Volume Method) techniques. The Lagrangian particle method VPM is suitable for modeling of fine and fast flow structures whereas the grid-based techniques like FVM have strong advantages in the modeling of large-scale motions. A fundamental assumption of this novel approach is the decomposition of any physical quantity into the grid based (large scale) and the fine scale parts, whereas large scales are resolved on the grid and fine scales are represented by particles. Dynamics of large and fine scales is calculated from two coupled transport equations one of which is solved on the grid hereas the second one utilizes the Lagrangian grid free VPM. The method is implemented into OpenFOAM in a parallel code and can be used for computations of complex flows on arbitrary unstructured grids. The performance of
the method is illustrated for three-dimensional flows like the isotropic homogeneous turbulence, free jets, wall bounded flows and mixing.