Numerical Simulation of Water Impact on a Wave Energy Converter in Free Fall Motion

Abstract

Results are presented for the 3D numerical simulation of the water impact of a wave energy converter in free fall and subsequent heave motion. The solver, AMAZON-3D, employs a Riemann-based finite volume method on a Cartesian cut cell mesh. The computational domain includes both air and water regions with the air/water boundary captured automatically as a discontinuity in the density field thereby admitting break up and recombination of the free surface. Temporal discretisation uses the artificial compressibility method and a dual time stepping strategy. Cartesian cut cells are used to provide a boundary-fitted grid at all times. The code is validated by experimental data including the free fall of a cone and free decay of a single Manchester Bobber component.

Efficient Nonlinear Hydrodynamic Models for Wave Energy Converter Design—A Scoping Study

“…The Euler equations are only employed in a small number of WEC simulations and analysis studies, which are listed in Table 1. Hu et al [64,65] use the Euler equations to simulate two very nonlinear WEC scenarios: extreme waves and slamming. The development of the AMAZON-3D NWT for the study of wave loading on WECs is described in [64], where some preliminary results of the Manchester Bobber WEC in regular waves and the generation of extreme waves without the WEC in the NWT are presented.…”

“…The development of the AMAZON-3D NWT for the study of wave loading on WECs is described in [64], where some preliminary results of the Manchester Bobber WEC in regular waves and the generation of extreme waves without the WEC in the NWT are presented. In [65], the water impact on a WEC in free-fall motion is simulated in AMAZON-3D, to provide insight into the expected pressure loads on the WEC hull from slamming events. Westphalen et al [66] also perform simulations of the Manchester Bobber WEC using AMAZON-3D, as a part of a study that compares four different CFD modelling approaches for the simulation of WEC survivability design scenarios.…”