A hybrid decomposition parallel algorithm for multi-scale simulation of viscoelastic fluids

The method of Brownian configuration fields (BCF) is a promising multi-scale approach for the simulation of viscoelastic fluids, however, it is a computationally expensive method, which restricts its application in complex scenarios. Therefore, it is of great importance to optimize the parallel implementation in order to improve computational efficiency. In this paper we propose a hybrid decomposition parallel algorithm named : MCDPar, which enables the simulation problem to be decomposed simultaneously over mesh cells and the Brownian configuration fields. Compution processes are split into multiple groups and Brownian configuration fields are equally associated with these groups. Meanwhile, within each group the processes are concurrently executed based on the traditional mesh decomposition approach. Finally we implemented the MCDPar algorithm in a micro-macro numerical solver based on OpenFOAM. Experimental results show that the micro-macro simulation time of viscoelastic fluids is significantly reduced with improved scalability and parallel efficiency. In the test case with N-f = 2000 and N-cell = 262144, the speedup of the MCDPar is up to 9.23x with a 7.5x increase in number of cores compared to the original parallel algorithm.