THE DETERMINATION OF NONLINEAR FORCES OF THE SECOND ORDER DUE TO THE DIFFERENCE OF FREQUENCIES DURING THE MOTIONS OF THE SHIPS ON THE BI^ROMATIC WAVES
The article deals with the method of calculation of non-linear second-order forces due to the difference of frequencies which arise during the oscillation of the ship on the bidiromatic waves in deep water. The emergence of these forces is due to the interaction of the incident, diffracted and forced waves.The calculation method used is a combined method of Helmholtz integral equations. This method allows to avoid the negative impact of "irregular frequencies" that are typical when using the classical method of integral equations. At the same authors carried out an accurate account of non-linear boundary condition at the free surface of the liquid.Nonlinear forces acting on a ship are determined on the basis of the slender body theory. The article analyzes the influence of various combinations of bichromatic wave frequencies on the amplitude values of nonlinear forces and moments. Comparisons of these forces with nonlinear steady forces due to doubled frequency are given. For the first time, diagrams of the distribution of these nonlinear forces and moments in a wide range of frequencies of bichromatic waves for various types of ships s are given