A novel approach for the computation of hydrodynamic forces due to random nonlinear water waves acting on a cylindrical pile is presented. This approach is based on paths of fluid particles underneath of solutions to the nonlinear Schrödinger equation (NLS). This is computationally very efficient compared to the determination of the corresponding solutions of the Euler equations or even of the Navier–Stokes equation.In this chapter, specific solutions of the NLS, such as solitons, are considered in the presence of gusty wind. Using a spectral scheme for the numerical computation, the corresponding velocity potential is obtained. Depending on the corresponding wave envelope, the wave kinematics, the particle trajectories, and the forces acting on a submerged cylindrical pile are computed. Thereby, the equation of Morison is used for the computation of the hydrodynamic forces. With this, also effects of random wind on particle trajectories and forces are studied in detail. With the presented new approach it is possible to determine very efficiently the loads on structures that are exhibited to complicated random nonlinear ocean waves.
