Mesh refinement for LBM simulations on Cartesian meshes

The use of mesh refinement in CFD is an efficient and widely used methodology to minimize the computational cost by solving those regions of high geometrical complexity with a finer grid. The author focuses on studying two methods, one based on multi-domain and one based on irregular meshing, to deal with mesh refinement over LBM simulations. The numerical formulation is presented in detail. Two approaches, homogeneous GPU and heterogeneous CPU+GPU, on each of the refinement methods are studied. Obviously, the use of the two architectures, CPU and GPU, to compute the same problem involves more important challenges with respect to the homogeneous counterpart. These strategies are described in detail paying particular attention to the differences among both methodologies in terms of programmability, memory management, and performance.