SPH-FV Coupling for solving 3D free-surface flows

Recently, an algorithm for coupling a Finite Volume (FV) method, that discretize the Navier-Stokes equations on block structured Eulerian grids, with the weakly-compressible SPH has been presented. This coupling takes advantage of the SPH method to discretize flow regions close to free-surfaces and a Finite Volume method to resolve the bulk flow and the wall regions where grid stretching can be favourably used. The information exchange between the two numerical schemes is established through overlapping zones. In the present work such a coupling paradigm is extended to the 3D framework. In particular, the extension of the algorithms for handling particle creation/deletion are described and issues related to free-surface intersection with each sub-domain boundary are addressed. Efficiency and accuracy achieved by the coupled solver are tested on challenging problems involving large free surface deformations and vorticity generation, such as the flow past a cylinder below a free surface and the breaking wave generated by a ship bow in forward motion.