Modelling of rotating vertical axis turbines using a multiphase finite element method

Abstract

We combine the unified continuum fluid-structure interaction method with a mul-

tiphase flow model to simulate turbulent flow and fluid-structure interaction of rotating ver- tical axis turbines in offshore environments. This work is part of a project funded by the Swedish Energy Agency, which focuses on energy systems combining ecological sustainability, competitiveness and reliability of supply. The numerical methods used comprise the Galerkin least-squares finite element method, coupled with the arbitrary Lagrangian-Eulerian method, in order to compute weak solutions of the Navier-Stokes equations for high Reynolds numbers on moving meshes. Mesh smoothing methods help to improve the mesh quality when the mesh undergoes large deformations. The simulations have been performed using the Unicorn solver in the FEniCS-HPC framework, which runs on supercomputers with near optimal weak and strong

scaling up to thousands of cores.