Abstract
In this paper, we investigated how the added mass, the hydrodynamic damping and the drag coefficient of a Wave Energy Converter (WEC) can be calculated using DualSPHysics. DualSPHysics is a software application that applies the Smoothed Particle Hydrodynamics (SPH) method, a Lagrangian meshless method used in a growing range of applications within the field of Computational Fluid Dynamics (CFD). Furthermore, the effect of the drag force on the WEC’s motion and average absorbed power is analyzed. Particularly under controlled conditions and in the resonance region, the drag force becomes significant and can greatly reduce the average absorbed power of a heaving point absorber. Once the drag coefficient has been determined, it is used in a modified equation of motion in the frequency domain, taking into account the effect of the drag force. Three different methods were compared for the calculation of the average absorbed power: linear potential flow theory, linear potential flow theory modified to take the drag force into account and DualSPHysics. This comparison showed the considerable effect of the drag force in the resonance region. Calculations of the drag coefficient were carried out for three point absorber WECs: one spherical WEC and two cylindrical WECs. Simulations in regular waves were performed for one cylindrical WEC with two different power take-off (PTO) systems: a linear damping and a Coulomb damping PTO system. The Coulomb damping PTO system was added in the numerical coupling between DualSPHysics and Project Chrono. Furthermore, we considered the optimal PTO system damping coefficient taking the effect of the drag force into account.
Highlights
Wave energy is a potential source of clean electricity that can make a significant contribution to the de-carbonization of the world’s electricity supply
Before calculating the drag coefficient Cd, wer briefly checked whether DualSPHysics was able to accurately compute the hydrodynamic coefficients corresponding to the added
We investigated how the hydrodynamic coefficients of a floating body can be determined with DualSPHysics when using appropriate settings
Summary
Wave energy is a potential source of clean electricity that can make a significant contribution to the de-carbonization of the world’s electricity supply. A wide variety of devices to harvest wave energy, known as wave energy converters (WECs), have been designed over recent decades [1]. The type of WEC studied in the current research is the heaving point absorber, one of the most investigated types of WECs [3]. These devices typically consist of a floating buoy moved by the waves and connected to a PTO system, which converts the float’s movement into electricity. A complete review on the numerical methods used to simulate the hydrodynamic response of point absorbers can be found in [5]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
