Second-order Long Period Wave Forces on an Offshore Structure in Shallow Water (2nd report)

Abstract

In this paper, the second-order long period wave forces acting on a two-dimensional fixed obstacle of arbitrary shape in bichromatic waves in a finite depth water are investigated. In the evaluation, the second-order effect of a wave maker is included to satisfy the precise boundary condition in an experimental tank. The solution of the second-order diffraction problem is obtained by using hybrid type boundary integral equation method. One of the merit of this method is that the complicated second-order free surface condition can be treated easily by using the analytical form of second-order velocity potential which was derived in 1st report.Computations are done for a half immersed circular cylinder and the calculated results are compared with the results obtained from Green's second identity. These results are also compared with experimental values and the validity of the present method is discussed.