Direct CFD simulation of ship capsizing in stern quartering waves

  Objective  Ship capsizing induced by pure loss of stability is an important issue for research on the second-generation intact stability criteria proposed by IMO.

  Methods  A CFD solver based on the viscous theory is developed in combination with the dynamic overset approach and feedback controller for ship maneuver behavior, thereby simulating the course-keeping of a free-running ship with rudders and propellers in stern quartering waves. 6-DOFs motions are predicted for the ship under pure loss of stability with stability failure mode and capsizing assessment.

  Results  The results indicate that large amplitude roll motion occurs with the continuous loss of stability, and the extreme roll eventually leads to the ship capsizing. The yaw angle increases significantly with the variation in roll angle, which indicates that the rudder deflection is unable to control the ship's course effectively, resulting in the broaching phenomenon.

  Conclusions   The results of this study demonstrate that the CFD approach can accurately simulate the stability failure mode and capsizing of a ship, providing references for research on the second-generation intact stability criteria, and technical support for the development of direct stability assessment under pure loss of stability.