However, Savonius rotors are also proposed and tested for OWCs (Ram et al., 2010). Onshore OWC is relatively cheap because there is no need for sub-sea grid connection, easier to maintain and has easy accessibility. However, onshore OWC devices capture less wave energy due to the loss of energy to seabed friction when compared to its near-shore and offshore counterparts. Literature review shows there are varieties of wave energy devices in existence which can be employed to extract power form ocean surface waves. There is a

vast amount Palbociclib of knowledge and it can be further used to develop new devices or even improve on the existing devices. Oscillating Water Column (OWC) is one of the best designed concepts to extract wave energy. However, all the existing OWC use air turbines to convert the pneumatic energy (compressed air) to mechanical and then electrical energy. The turbines that use the oscillating flow of air have problems such as relatively high rotational speed variation and aerodynamic losses due to high noise coming from the turbine passage at extreme sea conditions. To address this problem, Fukutomi and Nakase (1990) and Choi et al., 2007 and Choi et al., 2008 selleck inhibitor have proposed a Direct Drive Turbine (DDT)

which uses water as the working fluid. Prasad et al. (2010) presented the results from a detailed study of the effect of front guide nozzle shape on energy conversion in DDT for wave power generation. The turbine is fully submerged in water and under the action of incoming waves generates power bi-directionally. Therefore, the present study aims to use a DDT of the cross-flow type (Banki Turbine) to generate power from ocean surface waves. The cross-flow turbine is widely used for hydro-power applications and it possesses many advantages; as stated by Olgun (1998), apart from cost-effectiveness and ease of construction; it is self-cleaning, there is no problem

of cavitation and its efficiency does not depend much on the flow rate compared to other types of turbines. A Numerical Wave-tank (NWT) is used in the present work and the waves in the numerical wave-tank were generated by a piston type wave maker which was located at the wave-tank inlet. The paper is divided into two parts. The first part looks at the flow characteristics and Neratinib primary energy conversion in the base model at different wave periods without the turbine. More specifically, the flow in the front guide nozzle and the augmentation channel is studied. The second part involves simulation including the cross-flow turbine. The model was first validated with experimental data at a wave period of 2 s. Upon this, the model was further tested at wave periods of 2.5 s and 3 s at different turbine speeds. The entire model is solved in a commercial CFD code ANSYS-CFX. To test the accuracy of numerical method used to generate waves in NWT the code was validated against experimental data.