EXPERIMENTAL INVESTIGATION OF THE LIFT COMPONENT OF ROLL DAMPING

The lift force and turning moment acting on a model towed obliquely to the direction of motion have been measured. Two models were used; one of them was tested fitted with and without a rudder. These measuremen ts were used to determine the magnitude of the lift coefficient and th e point of application of the transverse force acting on the model. Th e data were then used to determine the lift component of the roll damp ing moment. It has been found that the equivalent linear damping coeff icient due to lift is a nonlinear function of the forward speed of the ship.