LARGE SCALE EXPERIMENTS ON FARMS OF HEAVING BUOYS TO INVESTIGATE WAKE DIMENSIONS, NEAR-FIELD AND FAR-FIELD EFFECTS

Vasiliki Stratigaki, Peter Troch, Timothy Stallard, Jens Peter Kofoed, Michel Benoit, Giovanni Mattarollo, Aurelien Babarit, David Forehand, Matthew Folley

Abstract


The shrinking reserves of fossil fuels in combination with the increasing energy demand have enhanced the interest in renewable energy sources, including wave energy. In order to extract a considerable amount of wave power, large numbers of Wave Energy Converters will have to be arranged in arrays or farms using a particular geometrical layout. The operational behaviour of a single device may have a positive or negative effect on the power absorption of the neighbouring WECs in the farm (near-field effects). Moreover, as a result of the interaction between the WECs within a farm, the overall power absorption and the wave climate in the lee of the WECs is modified, which may influence neighbouring farms, other users in the sea or even the coastline (far-field effects). Several numerical studies on large WEC arrays have already been performed, but large scale experimental studies on near-field and far-field wake effects of large WEC arrays are not available in literature. Within the HYDRALAB IV European programme, the research project WECwakes has been introduced to perform large scale experiments in the Shallow Water Wave Basin of DHI, in Denmark, on large arrays of point absorbers for different layout configurations and inter-WEC spacings. The aim is to validate and further develop the applied numerical methods, as well as to optimize the geometrical layout of WEC arrays for real applications.

Keywords


wave energy converters; WEC; WEC arrays; WEC farms; WEC wakes; wake effects; renewable energy; large-scale experiments; wave energy; HYDRALAB IV

References


Aelbrecht, D. 1997. ARTEMIS 3.0: a finite element model for predicting wave agitation in coastal areas & harbours including dissipation, Transactions on the Built Enviroment, vol.27, Wit Press, ISSN 1743-3509.

Alexandre, A., T. Stallard, and P.K. Stansby. 2009. Transformation of Wave Spectra across a Line of Wave Devices. Proceedings of the 8th European Wave and Tidal Energy Conference, Uppsala, Sweden.

Ashton, I., L. Johanning, and B. Linfoot. 2009. Measurement of the Effect of Power Absorption in the Lee of a Wave Energy Converter, Proceedings of the 28th International Conference on Offshore Mechanics & Arctic Engineering, Honolulu, Hawaii, OMAE 2009, vol. OMAE2009-79793.

Babarit A., H. Mouslim, A. Clement, and P. Laporte-Weywada. 2009. On the numerical modelling of the non-linear behaviour of a wave energy converter. Proceedings of the 28th International Conference on Offshore Mechanics & Arctic Engineering, Honolulu, Hawaii, OMAE 2009.

Beels, C., P. Troch, G. De Backer, M. Vantorre, and J. De Rouck. 2010. Numerical implementation & sensitivity analysis of a wave energy converter in a time-dependent mild-slope equation model, Coastal Engineering, Vol. 57(5), pp. 471-492.

http://dx.doi.org/10.1016/j.oceaneng.2011.12.025

Budal, K., J. Falnes, A. Kyllingstad, and G. Oltedal. 1979. Experiments with point absorbers in regular waves. Proceedings of the 1st Symposium on Wave Energy Utilization, pp. 253–282, Gothenburg.Sweden.

Child, B.F.M. 2011. On the configuration of arrays of floating wave energy converters. Ph.D, Thesis, Edingburgh University.

Count, B.M. and E.R. Jefferys. 1980. Wave power, the primary interface. Proceedings 13th Symposium for Naval Hydrodynamics, 8, 1-10.

De Backer, G. 2009. Hydrodynamic Design Optimization of wave energy converters consisting of heaving point absorbers, PhD thesis, Department of Civil Engineering, Ghent University, Belgium.

Delhommeau G. 1987. Le problème de diffraction radiation et de résistance de vagues : étude théorique et résolution numérique par la méthode des singularités, Thèse Ecole Nationale Supérieure de Mécanique, Nantes.

Durand M., A. Babarit, B. Pettinotti, O. Quillard, J. Toularastel, and A. Clement. 2007. Experimental validation of the performances of the SEAREV wave energy converter with real time latching control. Proceedings of the 7th European Wave and Tidal Energy Conference, Portugal.

Folley, M., A. Babarit, L. O' Boyle, B. Child, D. Forehand, K. Silverthorne, J. Spinneken, V. Stratigaki, and P. Troch. 2012. A review of numerical modeling of wave energy converter arrays, Proceedings of the 31st International Conference on Offshore Mechanics & Arctic Engineering, Rio de Janeiro, Brazil.

PMCid:3249473

Gilloteaux J.C., A. Babarit, G. Ducrozet, M. Durand, and A. Clement. 2007. A nonlinear potential model to predict large-amplitude motions: application to the SEAREV wave energy converter. Proceedings of the 26th International Conference on Offshore Mechanics & Arctic Engineering, USA.

PMCid:1933327

Marquis, L., M. Kramer, and P. Frigaard. 2010. First Power Production figures from the Wave Star Roshage Wave Energy Converter. Proceedings of the 3rd International Conference on Ocean Energy (ICOE), Bilbao.

MIKE21,DHI-Water.Environment.Health, http://www.dhigroup.com. Millar, D.L., H.C.M. Smith, and D.E. Reeve. 2006. Modelling analysis of the sensitivity of shoreline change to a wave farm. Ocean Engineering, 34, 884-901.

Payne G., J. Taylor, T. Bruce, and P. Parkin. 2008. Assessment of boundary-element method for modelling a free-floating sloped wave energy device. Part 2: Exp. validation. Ocean Engineering, 35: 342–357.http://dx.doi.org/10.1016/j.oceaneng.2007.10.008

Stallard T., P.K. Stansby, A. Williamson. 2008. An experimental study of closely spaced point absorber arrays. Proceedings of the 18th International Offshore & Polar Engineering Conference, Canada. Booij, N., I.J.G. Haagsma, L.H. Holthuijsen, A.T.M.M. Kieftenburg, R.C. Ris, A.J. van der Westhuysen, and M. Zijlema. 2007. SWAN cycle III version 40.51AB User Manual.

Stratigaki, V., P. Troch, T. Stallard, J.P. Kofoed, M. Benoit, G. Mattarollo, A. Babarit, D. Forehand, and M. Folley. 2011. Large scale experiments on wave energy converter farms to study the nearfield effects between the converters and the far-field effects on other users in the coastal area. HYDRALAB IV, Research report.

Stratigaki, V., and P. Troch. 2012. A short introduction to the wave propagation model MILDwave. MILDwave manual, Department of Civil Engineering, Ghent University.

Stratigaki, V., P. Troch, M. Vantorre, and M. Folley. 2012. Development of a point absorber Wav Energy Converter for investigation of wake effects in large scale experiments. Proceedings of the 4th International Conference on the Application of Physical Modelling to Port and Coastal Protection (Coastlab12), Ghent, Belgium.

Troch, P., C. Beels, J. De Rouck, and G. De Backer. 2010. Wake effects behind a farm of wave energy converters for irregular long-crested and short-crested waves. Proceedings of the International Conference on Coastal Engineering, No. 32(2010), Shanghai, China. Paper #: waves.22. Retrieved from http://journals.tdl.org/ICCE/.

Troch, P. 1998. MILDwave – A numerical model for propagation and transformation of linear water wavaes. Internal Report, Department of Civil Engineering, Ghent University.

PMid:9689969

Vantorre M. 1985. Third-order potential theory for determining the hydrodynamic forces on axisymmetric floating and submerged bodies in a forced periodic heave motion. PhD thesis, Ghent University.

Vantorre M., R. Banasiak, R. Verhoeven. 2004. Modelling of hydraulic perforamance and wave energy extraction by a point absorber in heave. Applied Ocean Research; 26:61–72.http://dx.doi.org/10.1016/j.apor.2004.08.002

Venugopal, V. and G.H. Smith. 2007. Wave climate investigation for an array of wave power devices. Proceedings of the 7th European Wave and Tidal Energy Conference, Porto. WAMIT, User Manual. http://www.wamit.com/manual.htm.

Weller S., T. Stallard, P.K. Stansby. 2009. Experimental measurements of irregular wave interaction factors in closely spaced arrays. Proceedings of the 8th European Wave and Tidal Energy Conference, Sweden.


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