Simulating 3D waves crashing against large 3D solid structures, such as ship hulls, piers, or large coastlines in the case of a tsunami, require a large number of cells even for a low-accuracy simulation. The 2D Shallow Water Equation (SWE) model delivers satisfactory simulations for the same scenarios, using a much lower number of cells, and therefore, at a lower cost. However, as a 2D model, it fails to resolve the 3D effects (e.g. near obstacles). This leads us to think of a solver in which we could combine the low cost of SWE with the capability of the Navier Stokes Equations to capture 3D effects.

In this research, we partition the domain into 2D and 3D subdomains, in which we use a 2D SWE and 3D Navier-Stokes models, respectively. We implement the coupling of the solvers using the preCICE library, and we focus on breaking-dam and open-channel-flow scenarios for validating our results.

Keywords: multiphysics, fluid-fluid coupling, SWE, preCICE, OpenFOAM