Aurélien Babarit

Bio: Aurélien Babarit is an academic researcher from École centrale de Nantes. The author has contributed to research in topics: Offshore wind power & Wind power. The author has an hindex of 22, co-authored 53 publications receiving 2925 citations. Previous affiliations of Aurélien Babarit include Centre national de la recherche scientifique.

Theoretical and numerical aspects of the open source BEM solver NEMOH

Abstract: The aim of this paper is to provide the key theoretical and numerical aspects of the NEMOH software. NEMOH is a numerical solver for computations of first order hydrodynamic coefficients in frequency domain. It is based on linear free surface potential flow theory. It has been developed in Ecole Centrale de Nantes for 30 years. It has been released in open source in January 2014. This paper starts with recalling the assumptions and the resulting boundary value problem for the free surface flow around a body with an arbitrary condition for the normal velocity on the body surface. Then, it is recalled how the 3D flow problem can be transformed into the 2D problem of a source distribution on the body surface using Green's second identity and the appropriate Green function. Discretization of the mathematical problem using the constant panel method leads to a linear matrix problem whose coefficients are the influence coefficients. Depending on the distance between the source and field point, the influence coefficients are calculated analytically or approximately. Irregular frequencies are removed by adding constraints on the interior flow problem. Hydrodynamic coefficients for usual diffraction and radiation problems can be obtained by specifying to the solver the appropriate body conditions. The flexibility in specifying the body conditions allows dealing with complex structures, e.g deformable wave energy converters. Eventually, it is explained how far field coefficients and free surface elevation can be obtained from the solver outputs.

Wave energy utilization: A review of the technologies

Abstract: Sea wave energy is being increasingly regarded in many countries as a major and promising resource. The paper deals with the development of wave energy utilization since the 1970s. Several topics are addressed: the characterization of the wave energy resource; theoretical background, with especial relevance to hydrodynamics of wave energy absorption and control; how a large range of devices kept being proposed and studied, and how such devices can be organized into classes; the conception, design, model-testing, construction and deployment into real sea of prototypes; and the development of specific equipment (air and water turbines, high-pressure hydraulics, linear electrical generators) and mooring systems.

A review of wave energy converter technology

Abstract: Ocean waves are a huge, largely untapped energy resource, and the potential for extracting energy from waves is considerable. Research in this area is driven by the need to meet renewable energy targets, but is relatively immature compared to other renewable energy technologies. This review introduces the general status of wave energy and evaluates the device types that represent current wave energy converter (WEC) technology, particularly focusing on work being undertaken within the United Kingdom. The possible power take-off systems are identified, followed by a consideration of some of the control strategies to enhance the efficiency of point absorber-type WECs. There is a lack of convergence on the best method of extracting energy from the waves and, although previous innovation has generally focused on the concept and design of the primary interface, questions arise concerning how best to optimize the powertrain. This article concludes with some suggestions of future developments.

Review of wave energy technologies and the necessary power-equipment

Abstract: The wave energy is having more and more interest and support as a promising renewable resource to replace part of the energy supply, although it is still immature compared to other renewable technologies. This work presents a complete analysis of the wave energy technology, starting with the characterisation of this global resource in which the most suitable places to be exploited are showed, and the classification of the different types of wave energy converters in according to several features. It is also described in detail each of the stages that are part in the energy conversion, that is, from the capture of the energy from the waves to the extraction of a proper electrical signal to be injected to the grid. Likewise, existing offshore energy transmission alternatives and possible layouts are described.