The oscillating water column (OWC) wave energy converter is probably the most attractive way of converting the energy from the waves into electricity due to its simplicity and reliability. Shoreline full-scale prototypes were built in the 1990s and have proved the concept. However, largescale exploitation of wave energy can only be performed off the coast, where large arrays of floating OWCs are to be deployed.
This paper describes the testing, in a wave flume, of a 1:120th-scale model of an axisymmetric floating OWC with non-uniform tail tube cross section. The device consists in a floater pierced by a hollow cylinder opened at the bottom to the sea water and at the top to the pneumatic chamber. A turbine simulator was placed at the top of the pneumatic chamber. Several values of the turbine damping coefficient were tested to assess damping influence on the system dynamics when subject to regular waves. Two mooring configurations are tested: one constraining the floater motion to heave; the other was a slack-mooring. The motion of the floater and of the inner water column, the chamber air pressure and the reflection of waves are analysed. A comparison with numerical results based on linear wave theory is presented.
