Influences of surface waves on the power generation performance of a ocean current energy turbine

It is known that wave has significant influence on ocean current turbines during the process of collecting energy. In order to study the influence of waves on the hydrodynamic performance of a near-surface vertical axis water turbine (VAWT), this paper carries out a series of two-dimensional transient computational fluid dynamics (CFD) simulation. First, a two-dimensional numerical wave basin based on CFD is built by defining inlet boundary. The accuracy of the numerical method is ensured through comparison between numerical wave shape and theoretical Stokes wave shape. The influences of waves are quantitatively analyzed by separately discussing hydrodynamics performances and flow structures of a VAWT under different wave heights and submerged depth. It is found that the average torque, the fluctuation amplitude of the torque and power coefficient increase with the increased wave height, and decrease with the increased submerged depth.