The use of numerical flow simulations (based on CFD) in maritime industry applications has become increasingly relevant in recent years. Thanks to accurate calculations of the flow field, the propeller design can be fine-tuned to achieve optimum efficiency. The CFD analysis can be extended to include the actual hull geometry, thereby replacing conventional model scale testing. Nowadays this can be carried out within commercially acceptable time and cost limitations.
CFD simulations require an accurate methodology for calculating the bare hull resistance, the open water performance of the propeller, and the self-propulsion condition. The method is sufficiently robust to handle a large range of vessel types, including fishing vessels.
Wärtsilä carried out numerical simulations of the propeller performance for a new fishing vessel built at the MacDuff Shipyard in Scotland. The accuracy of the method has been established during the validation process, where the CFD results were compared with the available experimental data. The analysis helped to secure the compatibility of the hull resistance and the propeller performance, for a range of different hull and propeller designs.
Numerical flow simulations make it possible to ‘dive’ into the virtual world and obtain a more detailed analysis of the occurring flow phenomena. This helps in identifying those areas where the largest improvements can be made in order to reach optimal performance.