There is a growing demand for renewable sources of energy of which wave energy conversion is one. The Ocean Falls is an oscillating water column (OWC) system invented by BAM Infraconsult b.v. This system differs from conventional OWC systems since it includes a connection tube and an adjustable back wall. The OWC system is a resonance system for which maximum efficiency is obtained once the natural frequency matches the incoming wave frequency. This thesis focusses on the modelling of the OWC system with ANSYS AQWA and ANSYS Fluent. A parametric model and a CFD model are developed to assess the performance of the OWC system. An optimum is sought for in terms of system performance, constructability and cost effectiveness. Eventually a conceptual design of the Ocean Falls OWC system is made to assess the technical- and economic feasibility.