An accurate particle-mesh method for simulating charged particles in wall-bounded flows

Abstract

A numerical framework for accurately computing electrically charged particles in wall-bounded flows is presented. This work builds upon the particle-particle particle-mesh (P3M) approach, which is traditionally restricted to cubic periodic domains. Here we propose an extended approach that retains the same accuracy and cost savings for non-periodic wall-bounded flows. The solution to the electric Poisson equation is performed agnostic to the presence of any walls, allowing for the use of fast Fourier transforms. The contribution from periodic images are removed by exploiting the linearity of the Poisson equation and strategically mapping the particle charge to the grid. A signed-distance levelset function is used to enforce appropriate boundary conditions. The accuracy of the proposed approach is quantified and compared to existing schemes. The framework is then demonstrated on a polydisperse distribution of charged particles in a turbulent pipe flow. The effect of charge on velocity statistics and deposition rate is reported.