AbstractU-OWCs are Wave Energy Converters belong in to the family of Oscillating Water Column. The interaction between waves and a U-OWC breakwater produces an unknown pressure distribution on the breakwater wall, due to the motion inside the plant. In order to evaluate the force acting on a U-OWC breakwater produced by regular waves, we carried out an experiment in a 2D numerical flume. The computational domain is equipped by a piston-type wavemaker, in the left extremity side and a U-OWC breakwater on the opposite side. The water-air interaction is taken into account by means of the Volume Of Fluid (VOF) model implemented in the commercial CFD code Ansys Fluent. Both air and water flow fields are assumed to be unsteady and are computed by solving the Reynolds-Averaged Navier-Stokes (RANS) equations. In the numerical model, air is considered as an ideal gas, in order to take into account the compressibility inside the plenum chamber. Results were compared with a theoretical model on a traditional vertical breakwater and experimental results obtained through an experiment directly at sea, off the beach of Reggio Calabria, in the eastern coast of the Straits of Messina (Southern Italy). As observed in the physical experiment at sea, the pressure distribution are strongly influenced by the absorption of the plant. Indeed, in case of high performance of the U-OWC, we found a deformation of the pressure distribution in respect to the theoretical one, especially near the outer opening of the plant. This deformation produces a lower in line force on the structure.
Ashlin J. A. , Sannasiraj. S. A., Sundar. V Wave forces on an Oscillating Water Column Device 8th International Conference on Asian and Pacific Coasts (APAC 2015) Procedia Engineering 116 ( 2015 ) 1019-1026
Boccotti P. (2007). Caisson breakwaters embodying an OWC with a small opening - Part I: Theory, Ocean Engineering 34 (5-6), 806-819.
Boccotti, P., Arena, F., Fiamma, V., Romolo, A., and Barbaro, G. (2012). Small-Scale Field Experiment on Wave Forces on Upright Breakwaters. J. Waterway, Port, Coastal, Ocean Eng., 138(2), 97-114.
Boccotti, P. Filianoti, V. Fiamma, F. Arena, (2007) Caisson breakwaters embodying an OWC with a small opening - Part II: A small-scale field experiment, Ocean Engineering 34 (5-6), 820-841.
Boccotti P, Wave Mechanics for Ocean Engineering, Elsevier Science, Oxford, UK, 2000.
Crema I., Simonetti S., Cappietti L., Oumeraci H. Laboratory Experiments on Oscillating Water Column Wave Energy Converters Integrated in a Very Large Floating Structure Proceedings of the 11th European Wave and Tidal Energy Conference (EWTEC), Nantes, France (2015)
Falcao Antonio F.O. and Joao C.C Henriques, (2016). Oscillating-water-column wave energy converters and air turbines: A review, Renewable Energy 85 (2016) 1391e1424.
Hughes, S.A., 1993, Physical Models and Laboratory Techniques in Coastal Engineering, Advanced Series on Ocean Engineering, Vol. 7. World Scientific, London, 568 pp
Liu Y.; H. Shi; Z. Liu ; Zhe Ma Experiment Study on a New Designed OWC Caisson Breakwater Proceedings of 2011 Asia-Pacific Power and Energy Engineering Conference
Ponti G. et al., The role of medium size facilities in the HPC ecosystem: the case of the new CRESCO4 cluster integrated in the ENEAGRID infrastructure, Proceedings of the 2014 International Conference on High Performance Computing and Simulation, HPCS 2014, art. no. 6903807, 1030-1033.
Lopez L., B. Pereiras, F. Castro, G. Iglesias Performance of OWC wave energy converters: influence of turbine damping and tidal variability Int. J. Energy Res., 39 (4) (2015), pp. 472-483
Thiruvenkatasamy K., S. Neelamani, M. Sato Nonbreaking wave forces on multiresonant oscillating water column wave power caisson breakwater J. Waterw. Port Coast. Ocean Eng., 131 (2) (2005), pp. 77-84 .