Interpolation methods for two-way coupled Euler-Lagrange simulation of finite-size bubbles

Abstract

Dispersed multiphase flow can be simulated by the Euler-Lagrange approach where the continuous phase is described on the Euler grid and the dispersed phase is treated as Lagrange points. The point-mass Euler-Lagrange method requires the bubble or particle size to be much smaller than the cell size when the interphase coupling is considered. Otherwise, numerical instabilities may arise. However, the point-mass prerequisite is hard to achieve, for example, if very fine grids are used to resolve turbulence in LES. Therefore, interpolation methods between the Euler and the Lagrange phase for finite-size bubbles which are bigger than or of the same size as numerical cells are discussed in this work. The spatially distributed coupling method is used for the Lagrange-to-Euler coupling. For the Euler-to-Lagrange coupling, a new approach is proposed and validated in different cases. Finally, a combination of coupling approaches is employed in a square bubble column reactor.