On the analysis of RANS-based full-scale power predictions

Power predictions for the test case of the 2016 LR Workshop on Ship Scale Hydrodynamic Computer Simulation have been carried out to simulate the full-scale performance of a self-propelled ship in ballast. When imposing sea trail conditions, typically the draught at zero speed, RPM and the obtained ship speed, the resulting difference between measured and predicted torque (or delivered power) and the imbalance between the predicted thrust and resistance values of the hull in propulsion have to be analyzed to asses the quality of the CFD predictions. From such an analysis correlation allowances for the CFD computations can be determined, that are required to predict the self-propulsion point. In this paper the aspects that influence the accuracy of such computations are discussed.