Résumé de la publication

The demand in renewable energy has significantly increased over a few years and, consequently, the industrial production of renewable energy has considerably expended. In the meantime, wind energy has matured, and many wind farms have been installed, both onshore and offshore. Offshore wind is an emerging field where current fixed-bottom technology is limited when water depths exceeds 50 m. Consequently new solutions are currently being explored, with, in particular, the development of floating supports. Moving offshore enable to capture stronger and more constant winds, but may lead to higher CAPEX and OPEX. One way to reduce costs is to use numerical simulation for optimizing the whole structure from the mooring lines to the blades. The numerical tools involved enable a fine prediction of the behavior the structures have under a large span of conditions, e.g. the loads applied on the structures when extreme events occur. These results can lead to an adjustment of the security coefficients of the wind turbines, which can reduce the CAPEX costs.

This work focuses on a methodology enabling the simulation of one or several floating wind turbines using full-CFD, with an accurate representation of their respective geometries. The software library used is ICI-Tech, developed at the High Performing Computing Institute of Centrale Nantes. A monolithic approach is used, with a single mesh in the simulation, where all the interfaces are defined using modified level-set functions. The Navier-Stokes equations are solved using stabilized finite elements and the Variational MultiScale formulation. In order to largely reduce the computational costs, an anisotropic and automatic mesh adaptation is done, which enables to capture physical phenomena having different orders of magnitude. The first results of mesh immersion and aerodynamic simulations are presented.


« This work was carried out within the framework of the WEAMEC, West Atlantic Marine Energy Community, and with funding from the Pays de la Loire Region »