Comparative study on wind load coefficients of ultra large container ship in different loaded conditions

The estimation of wind loads plays an important role in the efficient operation of a container ship's propulsion plant or on her maneuverability, as well as in ship building and arrangement on working deck. The computational fluid dynamics (CFD) numerical simulation is used to calculate the longitudinal, lateral and yawing moment wind loads coefficient for very large container ships. The obtained coefficients were compared with the results of Isherwood empirical equation, the deviation between them are analyzed. It can be seen that with the ship loading variation, the CFD results shown a significant dispersion from Isherwood equation, especially for the longitudinal and yaw moment coefficients. To further reveal the influential factors of wind loads, the pressure contours and airflow were presented and discussed. It was apparent, as expected, the shielding effect due to higher container configuration could increase the wind loads in general, and the bluff-body-effect of container ship could affect the airflow around the hull, which lead to the greater pressure difference between windward and leeward, therefor increased in additional wind loads for container ship. The proposed CFD numerical simulation method and relevant conclusions might provide a general concept of how the loaded condition influent the wind loads for ultra large container ship.