Parallel Overlapping Mechanism Between Communication and Computation of the Lattice Boltzmann Method

The lattice Boltzmann Method (LBM), different from classical numerical methods of continuum mechanics, is derived from molecular dynamics. The LBM has the following main advantages: including a simple algorithm, the direct solver for pressure, easy treatment of complicated boundary conditions and particularly parallel suitability. The most common models include the Single-Relaxation-Time (SRT) and Multiple-Relaxation-Time (MRT) collision models. In a conventional parallel computing model of LBM, communication and computing are performed individually. When the communication is performed, the computing is waiting in MPI processes. This will waste some waiting time. Therefore, the communication and computing overlapping parallel model was proposed. By the architecture of “Ziqiang 4000” supercomputer at Shanghai University, the hybrid MPI and OpenMP parallel model is proposed. The numerical results show that the presented model has better computational efficiency.