Abstract: A numerical prediction method of rolling damping was established for asymmetric catamaran with computational fluid dynamics ( CFD) method and overset grid technology． Firstly，the study simulated the rolling decay curves with different rolling angles and ship speed under different transverse and longitudinal space，and analyzed the rolling damping characteristics． Then based on 3D potential flow theory and considering the correction of the nonlinear rolling damping and nonlinear restoring，the rolling motion response of asymmetric catamaran in regular waves was calculated，and the characteristics of rolling motion under different wave directions were analyzed． Finally， model tests were carried out to verify the numerical prediction methods of rolling damping and rolling motion． It is showed that the model test results are close to the numerical prediction，and the transverse wave disturbance in the side body leads to greater rolling response than that in the main body of the asymmetric catamaran．

Key words: asymmetric catamaran, nonlinear rolling, computational fluid dynamics, 3D potential flow theory