A versatile immersed boundary method for multiphase flows*

A novel immersed boundary method (IBM) is proposed with the aim to apply it to incompressible particle-laden flows. The new Hybrid method (HyBM) relies on a regularization of the transfer function, allowing both symmetrical and non-symmetrical interpolation/spreading supports to be used. This allows to locally restrain the momentum transfer to the inside of the particle, hereby avoiding competing contributions from multiple particles when particles come into close contact, as well as to safely and accurately interact with domain boundaries.

The present methodology is validated and compared to the literature for several configurations in which the Reynolds number and the particle volume fraction are varied. These simulations are performed for fixed spheroidal particles on Cartesian grids, in our fully-coupled pressure-velocity algorithm solver. The results show that the HyBM accurately predicts near wall/particle-particle interactions without loss of accuracy of the overall method.