Summary The oscillating water column (OWC) is a more common type of wave energy converter (WEC) that has been the subject of the study and development for several decades. Multi–chamber oscillating water column (MC–OWC) devices or arrays have the advantage of being more efficient in energy extraction compared to a single chamber system, particularly in more chaotic sea states. A variety of single and array OWC devices have been proposed and studied on a small–scale, whereas few large–scale devices have been tested under ocean wave conditions. This paper provides a concise review of the current state of MC–OWC device development in laboratory conditions. The review highlights explicitly the main stages of MC–OWC device development for one ongoing study as an example. This review was based on the available information in the literature from 2003 to 2012, in addition, further work is presented as part of the current study at the University of Technology Sydney. This study is from 2015 to 2018. The discussion shows the challenges that a device needs to overcome to be more competitive with other WECs in the global of wave energy converter area.

Abstract-Wave Energy Converters (WECs) are being developed as a viable green energy solution to meet power needs for coastal communities. This paper presents the initial work on a fixed multi-chamber OWC (MCOWC) concept. The paper reports theoretical and experimental modeling. It begins with initial tests to verify the simple idealized model of a fixed OWC multichamber concept. These take place under small-amplitude regular-wave wave tank conditions. The analysis is carried through to assess the effect of the Capture Width (Hydrodynamic efficiency). Experimental data is put forward from the mounting of level sensors and anemometers to test the hydrodynamic performance of a fixed MCOWC at different wave periods. The orifice effects of the chamber on the relative amplitudes of the inner free water surface and air flow rate in the duct are investigated. The experimental results will be used as real case data in order to optimize the orifice area and to maximize the chamber power according to the air flow velocity above the water surface inside the chambers.

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Wave Energy Converters (WECs) have excellent potential as a source of renewable energy that is yet to be commercially realised. Recent attention has focused on the installation of Oscillating Water Column (OWC) devices as a part of harbor walls to provide advantages of cost-sharing structures and proximity of power generation facilities to existing infrastructure.In this paper, an incompressible three-dimensional CFD model is constructed to simulate a fixed Multi-Chamber OWC (MC-OWC) device. The CFD model is validated; the simulation results are found to be in good agreement with experimental results obtained from a scale physical model tested in a wave tank. The validated CFD model is then used for a benchmark study of 96 numerical tests. These investigate the effects of the PTO damping caused by the power take-off (PTO) system on device performance. The performance is assessed for a range of regular wave heights and periods. The results demonstrate that a PTO system with an intermediate damping can be used for all chambers in the MC-OWC device for most wave period ranges, except for the long wave periods. These require a higher PTO damping. An increased incident wave height reduces the device capture width ratio, but there is a noticeable improvement for long wave periods.