Efficiency and survivability analysis of a point-absorber wave energy converter using DualSPHysics

Abstract

Smoothed Particle Hydrodynamics (SPH) method is used here to simulate a heaving point-absorber with a Power TakeOff system (PTO). The SPH-based code DualSPHysics is first validated with experimental data of regular waves interacting with the point-absorber. Comparison between the numerical and experimental heave displacement and velocity of the device show a good agreement for a given regular wave condition and different configurations of the PTO system. The validated numerical tool is then employed to investigate the efficiency of the proposed system. The efficiency, which is defined here as the ratio between the power absorbed by the point-absorber and its theoretical maximum, is obtained for different wave conditions and several arrangements of the PTO. Finally, the effects of highly energetic sea states on the buoy are examined through alternative configurations of the initial system. A survivability study is performed by computing the horizontal and vertical forces exerted by focused waves on the wave energy converter (WEC). The yield criterion is used to determine that submerging the heaving buoy at a certain depth is the most effective strategy to reduce the loads acting on the WEC and its structure, while keeping the WEC floating at still water level is the worst-case scenario.

Modelling a Heaving Point-Absorber with a Closed-Loop Control System Using the DualSPHysics Code

“…Recently, ref. [38] proved the capability of DualSPHysics to carry out the efficiency and survivability analysis of a heaving point absorber.…”

On the Development of a Novel Approach for Simulating Elastic Beams in Dualsphysics With the Use of the Project Chrono Library

“…The DualSPHysics code has been applied to several multiphysics phenomena, for example in coastal engineering simulations: to compute forces exerted by large waves on the urban furniture of a realistic promenade [2], to study the run-up on a real armour block coastal breakwater [3,4] and to simulate large waves generated by land-slide events [5]. Other successful applications of DualSPHysics are performed in the field of renewable energies, for example the simulation of Wave Energy Converters (WECs) in several contexts: from the study of the moorings and floatings dynamics [6,7,8,9], to the efficiency [10] and survivability [11] analysis when combined with closed loops [12,13], PTO systems [4,14] or non linear mechanical constraints [15]. These works present first attempts of reproducing the effects of power take-off systems through simplified, although reliable, approaches.…”

A Numerical Validation of 3D Experimental Dam-Break Wave Interaction with a Sharp Obstacle Using DualSPHysics

“…DualSPHysics [25] is an advanced meshless solver with emphasis on free-surface flow modeling and has been shown to be robust and accurate in a wide range of applications: reproducing extreme wave events [26], coastal engineering simulations [27,28], fluid-solid interaction (FSI) [29,30], wave energy converters [31][32][33][34][35], etc. The peculiarities of this solver make it suitable for dam-break simulations, since it is naturally able to handle large deformations and violent impacts that involve solid obstacles [36,37]; it follows that SPH-based numerical models could be as effective as, if not better than, the traditional methods applied to the dam failure records, such as the ones based on 2D SWEs [38,39] or the VOF-or FEM-based [40,41] models.…”