Multiblock hybrid grid finite volume method to solve flow in irregular geometries

In this work, a finite-volume-based finite-element method is suitably developed for solving incompressible flow and heat transfer on collocated hybrid grid topologies. The method is generally applicable to arbitrarily shaped elements and orientations and, thus, challenges the potential to unify many of the different grid topologies into a single formulation. The key point in this formulation is the correct estimation of the convective and diffusive fluxes at the cell faces using a novel physical influence scheme. This scheme remarkably enhances the achieved solution accuracy. It is shown that the extended formulation is robust enough to treat any combination of multiblock meshes with dual element shape employments. In this regard, the solution domain is broken up into a number of different multiblock arrangements in which each block is filled with only one type of finite element shape. The combined grid can decrease the computational time and memory requirements and increase the numerical accuracy. The results of the extended formulation are validated against different benchmark and other solutions. The current results are in excellent agreement with the other solutions without exhibiting any disturbances around the block boundaries.