Ship-scale CFD benchmark study of a pre-swirl duct on KVLCC2

Installing an energy saving device such as a pre-swirl duct (PSD) is major investment for ship owner and prior to order reliable prediction of the savings required. Currently there no standard how be carried out, possible alternatives are both model-scale tests in towing tanks with associated scaling procedures, well methods based on computational fluid dynamics (CFD). This paper summarizes CFD benchmark study comparing industrial state-of-the-art ship-scale predictions power reduction through installation PSD, where objective was obtain indication reliability this kind gain insight into procedure affects results. It blind study, KVLCC2, which PSD mounted on, has never been built hence data available. The 10 participants conducted total 22 different respect baseline case without PSD. predicted reductions positive negative, average 0.4%, deviation 1.6%-units, when not considering two outliers large uncertainties Among variations present procedure, were found significantly influence predictions. First, geometrically resolved propeller model applying sliding mesh interfaces predicting higher compared simplified models. second factor notable wake field prediction, which, besides numerical configuration, affected by hull roughness considered.