出版社：The Japan Society of Naval Architects and Ocean Engineers
摘要：Slender-ship theory is applied to develop a new method of calculating with quantitatively good accuracy the effects of side-wall interference on the added-mass and damping coefficients of a ship in a waterway. The present paper is restricted to the radiation problem of heave and pitch motions with zero forward speed, but it may be easily possible to extend to the forward-speed case and the diffraction problem.In the outer region, 3-D Green function satisfying the boundary condition on the side walls is placed along the ship's centerline on the free surface to describe the outer solution. The side-wall boundary condition is satisfied by considering an infinite number of image ships, and then the summation of the resultant infinite series is analytically obtained in a closed form.In the inner region, the radiation condition and side walls are absent, and thus the inner solution is identical to that of Newman's unified theory : the strip-theory solution plus a homogeneous solution multiplied by a three-dimensional interaction coefficient. This interaction coefficient is determined by the compatibility requirement of the inner and outer solutions in an overlap region. Therefore through this coefficient, the side-wall effects are incorporated in the inner solution.Computations of the added-mass and damping coefficients are performed for a floating spheroid of length-beam ratio L/B=8 in a channel of breadth ratio B T/B=16, and of L/B in a channel of B T/B = 5. Numerical results are in virtually perfect agreement with the results by a newly-developed 3-D panel method. This suggests that the theory proposed can be quite effectively used also in estimating the tank-wall effects on the results of experiments in a towing tank with limited width.
