ROLL DAMPING CHARACTERISTICS OF A TRIMARAN DISPLACEMENT SHIP

This paper describes the analytical work on the roll damping characteristics of a trimaran ship. Two methods for estimating roll damping coefficients for trimaran ships are presented, the estimation of the coefficients from free decay experiment data using energy method, and the theoretical prediction of the coefficients directly from the hullform configurations of the trimaran ship. Both the method were verified by model experiment . Good agreement was achieved using the estimated nonlinear roll damping coefficients for free decay simulations, and for trimaran roll motion predictions. Effects of nonlinear roll damping, roll damping components, and roll motions of trimaran ship are analysed and discussed.