Open-water computations of a marine propeller using openfoam

Paper in proceeding, 2014

The flow around a marine propeller is studied by means of a RANS-type finite-volume (FV) method. A performance curve in open-water conditions is reproduced computationally and compared to data measured in a cavitation tunnel at Rolls-Royce in Kristinehamn, Sweden. In the computations, both periodic grids with a single propeller blade and grids featuring a full propeller with five blades are used. Two types of full propeller grids are applied. The first one consists of tetrahedral control volumes with prismatic layers near the propeller surface. The second grid type is a hybrid mesh that is a combination of separately meshed hexahedral and tetrahedral grids with an Arbitrary Mesh Interface (AMI) between the two parts. Turbulence is modelled by the two-equation SST k-! model as implemented in OpenFOAM .In steady-state computations, the Moving Reference Frame (MRF) approach is applied to account for the e↵ects due to rotation. In case of transient simulations, moving meshes with the sliding plane approach are utilized and the e↵ect of both numerical and iterative errors due to temporal discretization are studied. This study provides a solid basis for more complicated simulations by providing an understanding of errors caused by grid interfaces and the choice of spatial and temporal discretizations of the governing equations. In particular, the experiences with the AMI methodology will allow the analysis of contra-rotating propellers (CRP) with OpenFOAM. In addition, the robustness of the numerical method is considered in order to be able to produce a usable tool for industrial use.