Full-scale CFD Analysis of Oil and Chemical Tanker Advancing in Open Water and Comparison with Measured Mile Trial Data

Computational fluid dynamics analyses of a ship's operations are commonly conducted for scaled models or separately for propeller and hull. This approach is not ideal because reduced scale changes the flow around the ship's hull, while propeller simulations without the hull give only a portion of the required information. Due to stringent laws being applied in the maritime sector, it is necessary to develop a methodology for the virtual testing of a full-scale ship to reduce fuel consumption and harmful emissions to the environment. In this work, we have developed a full-scale model of an 184 m oil and chemical tanker, built in the Shipyard Trogir in Croatia, coupled with the realistic geometry of the propeller. The sliding mesh approach is used to give accurate predictions of flow behavior during open water tests. A comparison between sea trial measurements and full - scale simulation results is presented. Due to the high complexity of the geometry and transient nature of the calculations, which resulted in long calculation times, the simulations were conducted for finite volume mesh with reasonably fine resolution, which could be improved in a future study. Three simulation scenarios were investigated, each for different ship speed and propeller revolutions per minute, representing operating conditions from the measured sea trials. Additionally, the results are compared with commonly used analytical results from shipbuilding practice. The results of the numerical model show excellent agreement with experimentally measured sea trial data for all three points, while the numerical results show good agreement for 2 or 3 points when compared to analytical results. The developed numerical model will be used in a future study as a valuable tool to increase fuel efficiency and optimize the performance of the ship for the prescribed operating speed.