Create a fluid-structure simulation framework for cycloidal rotors

Abstract

The deformation of cyclorotor blades caused by aerodynamic forces and its effect on the rotor efficiency is not well understood. Therefore the aim of this thesis is to set up coupled Fluid Structure Interaction (FSI) simulations of cycloidal rotors. Furthermore, the results of this work shall create a base for prospective refinements of current cyclorotor CFD models in using a coupled simulation. For the FSI setup, the Computational Fluid Dynamics (CFD) simulation software OpenFOAM and the Multibody Dynamics (MBD) simulation software MBDyn are coupled using the coupling library preCICE. During this thesis, MBDyn models are set up and the advantages and limits of the currently existing preCICE OpenFOAM- and MBDyn-Adapter are discussed. To extend the coupling possibilities into the territory of rotating bodies, the creation of a custom OpenFOAM class is explained in this work. In addition, the influence of the cell displacement tolerance on mesh deformation is investigated and issues in OpenFOAM such as unwanted scaling or nonphysical motions are solved. Further, 2D and 3D setup cases are run and tested successfully on a High Performance Computing (HPC) cluster. Finally, certain coupling methods are reviewed and evaluated for the considered case.