Design and Optimization of an Oscillating Water Column Wave Energy Converter

Abstract

As the energy demand Increases, fossil fuels are giving way to other unconventional energy sources. Marine renewable energy, being one of them, offers a number of options to compete in this area. A wide-range of techniques were presented, studied and tested under real sea conditions. Amongst these marine converters, the Oscillating Water Column (OWC) stands out due to its simplicity, and robustness in turbulent sea conditions. In principle, the device leverages the succession of wave crests and troughs to either compress or suck air through a turbine that plays the role of a Power Take-Off device.The OWC's hydrodynamic performance depends upon the chamber's depth, the size of the water inlet and the position of the converter in relation to the free water surface.The objective of our study is to find the optimum output of a converter by methodically changing the geometry parameters and position in relation to the free water surface.For this purpose, we made an OWC That consists of a prototype parallelepiped air chamber, and came up with the following optimal configuration:Distance between the wave-making machine and the device; Water depth in the water column;Prototype's depth;Water inlet size.On the one hand, the obtained results show that the pairing of the geometrical parameters of the device and the condition of the system leads to an improvement in the hydrodynamic performance of the OWC. On the other hand, the various optima found make it possible to converge towards a frequency range close to the device’s natural frequency, which gives a considerable increase in the energy output.