A Numerical Study of Wave Energy Converter in the Form of an Oscillating Water Column Based on a Mixed Eulerian-Lagrangian Formulation

A desingularized boundary integral equation method (DBIEM) is employed to study the wave energy extraction by an oscillating water column (OWC) device. The method is based on a mixed-Eulerian-Lagrangian formulation. We examine the effects of the relative draught on the efficiency of 2D OWC energy converters. The oscillating air pressure inside the OWC chamber is modeled by assuming that the air is incompressible and the air-turbine mass-flow rate is proportional to the pressure difference (a linear turbine). For shallow draughts the numerical results agree well with available analytical results. The wave-excited seiching inside the extraction chamber is discussed and the variation of extraction efficiency with dimensionless air-chamber width for different immersion depths is reported.