Wave enhancement due to blockage in semisubmersible and TLP structures

An exact analytical method is described to solve the diffraction problem of a group of truncated vertical cylinders. In order to account for the inter action between the cylinders, Kagemoto and Yue's exact algebraic method is utilised (Kagemoto, H., Yue, D.K.P., 1986. Interactions among multiple thre e-dimensional bodies in water waves: an exact algebraic method. J Fluid Mec h, 46, 129-139). The isolated cylinder diffraction potential is obtained us ing Garret's solution and evanescent mode solutions are derived in a simila r manner (Garret, C.J.R,, 1971. Wave forces on a circular dock. J Fluid Mec h, 46, 129-139). Free surface elevations are calculated for an array of four cylinders and c ompared with experiments. Comparisons show good agreement. (C) 2000 Elsevie r Science Ltd. All rights reserved.