Shape optimisation of wall structures located in solitary wave flows

Abstract

ABSTRACT In this paper, we present a shape optimisation method for wall structures due to the wave force induced by a solitary wave. The fluid is assumed to be incompressible. Introducing the adiabatic assumption in addition, the acoustic velocity method presented by the author's group, the SUPG finite element method, is effectively used. To evaluate the wave force, we use the performance functional, which consists of the sum of the square of the wave force integrated between the starting and final times. The coordinates of the wall structure are regulated to obtain the minimum performance functional. The adjoint equation method is utilised to derive the gradient of the performance functional with respect to the coordinates. The simple weighted gradient method is employed as the minimisation procedure. Two numerical studies show that the results are consistent with existing structures and provide useful information on the practical design of coastal structures.