DETERMINATION OF INERTIAL DAMPING FORCES OF THE SECOND ORDER ARISING DURING THE SHIP'S MOTIONS, ON THE BASIS OF THREE-DIMENSIONAL POTENTIAL THEORY

The article reviews determination of the coefficients of the added masses and second-order damping on the basis of a three-dimensional potential theory. These coefficients are needed to compile and solve the differential equations of non-linear oscillations of the vessel. The presented solution in the domestic practice is a new one. The solution of the problem is carried out on the basis of the methods of integral equations taking into account the boundary conditions on the wetted surface of the vessel. The coefficients of the added masses and damping are determined in two ways, by solving the system of integral equations through second-order potentials and through their intensities. The results obtained are fully consistent with each other. Calculations of various coefficients for three different vessels are given. The calculations were performed for the case of an infinitely deep fluid, a fluid of limited depth for large values of the depth-to-draft ratio H / T, and are presented in comparison with calculations according to two-dimensional theory. It was shown that the results obtained are fully consistent with each other.