Evaluation of different dynamic mesh techniques with direct application to computational fluid dynamic analysis of a marine hydrokinetic cross-flow turbine

We present 4 different dynamic mesh techniques that could be applied directly to solve for the incompressible flow around a marine hydrokinetic (MHK) cross-flow turbine. All computational fluid dynamic (CFD) cases model a physical small turbine experiment with rotating mesh, deformable mesh, overset mesh, and moving immersed boundary. The experiment is conducted in a water tunnel facility at the turbine diameter based Reynolds number of 20,000. The near wake velocity field behind a vertical-axis straight three-bladed turbine (0.034 m diameter and 0.025 m chord length) is measured by 2D particle image velocimetry (mono PIV) and compared with results from the CFD analysis. All cases share similar a meshing topology and are solved with OpenFOAM PISO-Simple algorithm. The 4 techniques are assessed based on their accuracy, computational time, and total workload including mesh generation and post-processing. All of the cases can potentially be slightly modified for higher Reynolds number flow or applied to an axial-flow MHK turbine.