A multiblock joint PDF finite-volume hybrid algorithm for the computation of turbulent flows in complex geometries

A new hybrid joint probability density function (JPDF) solution algorithm for turbulent flows in complex 3D geometries is presented. The main focus is to demonstrate the applicability of JPDF methods for complex flows as observed in industrial applications. All elements of the algorithm are explained in detail and extensive validation studies are presented. A multiblock finite-volume solver, capable of handling globally unstructured, locally structured grids, was implemented together with a Lagrangian particle method. Efficient and robust particle management and accurate schemes for estimation and interpolation of particle statistics have been developed. For numerical efficiency particle sub-time stepping and an implicit finite-volume solver are applied. A fast coupling strategy was developed together with a multigrid method that allows very fast convergence on refined grids. Comparison with an established JPDF code for a bluff-body stabilized flow shows very good agreement. Furthermore, robustness and consistency of the algorithm for turbulent flow simulations with complex geometry is demonstrated.