Training school “Numerical modelling of WECs using SPH models” – WECANet coast action

January 10, 2020

A pan-European network of renewable marine energies focused on wave energy

🕒 From January 22 to 23, 2020

The pressure of climate change and the growing demand for energy have increased interest in renewable marine energy resources, such as wave energy, which can be obtained through wave energy converter (WEC) arrays.

However, the wave energy industry is currently at a critical juncture in its development, facing a number of challenges that require research to be refocused on a techno-economic perspective, where economics considers the full life-cycle costs of the technology. It also requires the development of WECs suitable for niche markets, as there are disparities in wave energy resources, wave energy companies, national programmes and investments in Europe. As a result, there are leading and non-leading countries in wave energy technology in Europe. The sector also needs to increase the confidence of potential investors by reducing (non-)technological risks. This can be achieved through an interdisciplinary approach involving engineers, economists, environmental scientists, legal and policy experts, etc. Consequently, the wave energy sector needs to receive the necessary attention compared to other more advanced and commercial ocean energy technologies (e.g. tidal power and offshore wind).

The formation of the first pan-European network on an interdisciplinary approach to marine wave energy will contribute to the large-scale deployment of the WEC Array by addressing current obstacles. The WECANet action aims for a collaborative approach, as it provides a strong networking platform that also creates space for dialogue between all stakeholders in wave energy. The main objective of WECANet is equal opportunities for research, training, networking, collaboration and funding for all researchers and practitioners, regardless of age, gender and country, in order to gain an understanding of the main challenges governing the development of the wave energy sector. Currently, 31 partner countries are active in the network.

The next training school “Numerical modeling of WECs using SPH models“, organized by Dr. Alejandro Crespo from Ephyslab (CIM-UVigo), will take place on January 22 and 23 at the Ourense Campus, University of Vigo, Spain.

This training school aims to provide a good introduction to meshless particle methods based on the SPH (Smoothed Particle Hydrodynamics) methodology and its benefits in the simulation of Wave Energy Converters (WECs). SPH is an ideal technique for simulating free surface flows and has several advantages compared to mesh-based methods for simulating violent wave-structure interactions. There is no special treatment to detect the free surface, so large deformations can be treated efficiently since there is no mesh distortion. Another important advantage is that complex boundary and interface motion is easy to handle. The open source code DualSPHysics was designed to use SPH for real engineering problems. The latest version of DualSPHysics includes, in the same meshless framework, functionalities to study wave-structure interaction, mooring forces and the numerical behavior of the power take-off (PTO) system. Mooring forces are solved with the MoorDyn library, which has also been coupled with DualSPHysics. The PTO (and the mechanical constraints of the device) can now be simulated using the coupling with the Project Chrono multiphysics library. This implementation allows for the efficient handling of kinematic constraints with user-defined dynamic properties such as friction and restoring coefficients, restoring forces of spring and damper systems, and user-imposed forces and trajectories. The efficiency of different WECs can be studied by calculating the hydrodynamic response of the devices interacting under different wave conditions. The survival of the devices will be analyzed in terms of the device movements and the mooring stresses in the anchors (and the grommets). The course will include lectures on: i) basics of the SPH method; ii) advantages and disadvantages compared to mesh-based CFD models; iii) description of the DualSPHysics code and recent developments; iv) applications of DualSPHysics in coastal engineering with a focus on WECs. In addition, a practical session is also organized where participants will learn to run simulations following some examples of: i) wave generation and propagation, ii) waves interacting with floating-only oscillating wave absorbers, iii) waves interacting with oscillating wave converters (OWSC), iv) waves interacting with Pelamis-like devices.

The agenda includes the following topics:

• Numerical hydrodynamic modeling for WEC

∙The hydrodynamics method of smoothed particles

∙The DualSPHysics code

∙Applications in coastal engineering

∙Practical session I: Dam breaking, regular waves

∙Coupling with Chrono and MoorDyn

∙Your own experience with SPH

∙Practical session II: Point absorber, tethered device

∙Practical session III: OWSC, Pelamis

Trainers:

∙Prof. Aleksander Grm Un