Coupling DPM with DNS for dynamic interphase force evaluation

Abstract

Discrete particle method (DPM) and direct numerical simulation (DNS) have been widely used to simulate gas-solid flow. DPM is computationally efficient but its accuracy is significantly dependent on the selection of interphase interaction models, whereas DNS is accurate but computationally expensive. In this work, we proposed a multi-scale method, DPM-DNS, where DNS of a relaxation process with modest computational cost was dynamically coupled to the DPM framework to evaluate the interphase force more accurately, thanks to the large density ratio and particle Stokes number in gas-solid flow. The simulation results demonstrated that the resultant interphase force distribution and concentration profiles calculated by DPM-DNS are almost identical to pure DNS, but the computational speed is more than 30 times higher than DNS, though still much lower than DPM. Future work on the relaxation scheme and the mapping algorithm between DPM and DNS may improve the efficiency of DPM-DNS more significantly.