A new correction scheme for two-way coupled point-particle methods for anisotropic grids

The accuracy of point-particle methods can degrade when the particle and fluid momentum equations are two-way coupled. In such cases, the fluid velocity at the location of the particle, which is often used as an estimation of the undisturbed fluid velocity in the discretized setting, can be altered by the particle, creating an error in the prediction of coupling forces. In this talk, we discuss a correction scheme to reduce this error by providing a more accurate estimation of the undisturbed fluid velocity. The proposed scheme can be applied to anisotropic rectilinear grids with arbitrary aspect ratio, arbitrary interpolation scheme, and particles that have a different size relative to the grid and density relative to the fluid. We evaluate the accuracy of the proposed scheme by comparing the computed settling velocity of individual and pair of particles under gravity on anisotropic rectilinear grids against analytical solutions, showing up to two orders of magnitude reduction in error in cases where the particle is up to 5 times larger than the grid that may have an aspect ratio of over 10. Additionally, a comparison against the particle-resolved simulation of decaying isotropic turbulence demonstrates the excellent accuracy of the proposed scheme.