3D unsteady flow simulation in an OWC wave converter plant

Abstract

This paper deals with a numerical simulation to predict the air flow behaviour inside the chamber of an OWC wave converter plant by use of FLUENT code. The flow is assumed to be compressible, viscous and unsteady. Calculations have been conducted by considering a typical geometry (PICO plant) with an oscillating water free surface. In our analyses, we have only considered the case of monochromatic sinusoidal excitations with various frequencies and fixed amplitude. Analyses are focused on the flow behaviour characteristics both in the chamber and in the duct in order to obtain the temporal variation of velocity, pressure, flow rate and pneumatic power fields. Also, the mean characteristics like RMS ones of these parameters are determined. A great attention is paid to show the process of energy generation inside the chamber which can be exploited by a rotating turbine. In our case, we have included in the model a linear law relating the pressure drop to the mass flow rate in order to take into account the presence of the turbine. This is achieved in FLUENT by considering a domain of porous media in the turbine location. Simulation results obtained for all frequencies show that this code is very powerful and suitable for flow prediction in such geometries. Also, the amount of energy and also the aerodynamic losses between the chamber and the duct are well calculated.