Development of a Computational Model for the Simulation of an Oscillating Water Column Wave Energy Converter Considering a Savonius Turbine

This work presents the development of a computational model for the simulation of an Oscillating Water Column device that converts wave flow into electrical energy. The device is placed into a wave channel and a Savonius turbine is inserted in the inlet/outlet duct of the converter. The modeling of the turbine is performed with a rotational moving mesh that simulates the turbine movement in stabilized operating conditions. This coupling provides the minimization of simplifying assumptions, addressing in a single problem the two phenomena inherent to the device approach: the two-phase, incompressible and turbulent flow of air and water in a wave channel containing the oscillating water column device and the incompressible and turbulent airflow passing through a rotational turbine. The computational model was verified/validated for a free stream turbulent flow over a Savonius turbine and verified for the case of wave flow over a converter without the inserted turbine. Results showed that the coupled model allowed obtaining not only available power but also mechanical power in the turbine. For the rotation imposed in the domain, the turbine did not affect the behavior of the wave flow that impinges on the chamber of the OWC device. An augmentation of the power coefficient of the turbine in comparison with turbines subjected to free stream flows was obtained, showing that the fairing of turbine can led to increased power takeoff.