A study on efficiency of semi-implicit, density-based solver for simulation of evaporating particle-laden flow

Abstract

In this work, we propose a semi-implicit, density-based solver for compressible, evaporating particle-laden flow, and investigate its efficiency. It is established on a Cartesian-grid-based, scalable, numerical framework named CUBE. In this solver, the governing equation system is divided into three subsystems (compressible Navier– Stokes, species transport, and Lagrangian), and these subsystems are weakly coupled in two ways. In the Lagrangian domain, the fuel spray is treated as a set of discrete particles, and the particle-source-in-cell (PSICell) method is employed for the coupling between the Eulerian and Lagrangian domains. Furthermore, the species transport and Lagrangian subsystems are subcycled with smaller time step, and the Navier–Stokes equation is temporally integrated with a larger step size. The proposed solver's verification and evaluation is conducted on the supercomputer Fugaku by comparing the results with those of the original, fully explicit solver where all equations have the same time step. The results show that this solver reduces the computational cost while ensuring similar accuracy. The solution of the proposed solver is consistent with that of the original solver. Finally, we brief our perspective on the future application of the proposed solver to our target problem: the largescale simulation of evaporating particle-laden flow in a combustor of an aviation engine.