Improvement of Wave Structure Interaction Calculation with Applications to the Shallow Water, Maneuvering in Waves and Hull Form Optimization

The goal of this work is to develop an improved hydrodynamic analysis methodology with applications to the numerical evaluation of Green’s function in shallow water, maneuvering in waves and floating systems hull optimization, which involves several distinct topics that are steps leading towards a definite goal. A numerical evaluation of Green’s function in finite water depth has been firstly developed using the Gauss-Legendre integral, with improved efficiency and efficacy in solving the 1st-order diffraction and radiation hydrodynamic problem. The expression of the 2nd-order wave loads has been derived in a unique form and the quadratic transfer function of a floating structure has been numerically estimated. Moreover, the effect of the floating structure’s forward speed or current velocity on the 2nd-order mean drift loads has been compared using Aranha’s formula, a far field method and the Neumann-Kelvin linearization, a near field method. Then, a framework involving both the seakeeping problem considering the 2nd-order wave loads with forward speed and the maneuvering problem has been developed to numerically evaluate maneuvering in waves. With the numerically estimated 1st-order and 2nd-order hydrodynamic quantities, an optimization framework has been applied to the hull of a floating structure which has been developed through the use of genetic algorithms. This improved wave and structure interaction calculation with its applications will present a meaningful improvement in the process of the design of offshore structures of ship shape and non-ship shape hull forms