Aghil Iranmanesh

The use of renewable energy, including sea energy, is one of the main and key issues in the marine economy. Wave energy converters are one of the key equipments in the basics of renewable energy and especially sea energy. In this research, Navier-Stokes equations have been solved in order to investigate the behavior of an immersed spherical wave energy converter under the influence of nonlinear waves. The control volume method and the virtual solution domain method have been used to perform the simulation. The flow regime in the present study is assumed to be laminar. The Volume of Fluid approach has been used to simulate the movement of the free surface of the fluid. In this research, the effects of various parameters such as the density of the submerged object, the type of excitation, the height of the water in the tank and the cross section of the tank on the behavior of the submerged wave energy converter have been studied. In order to check the accuracy of the applied method, the results of the present study have been compared with the existing laboratory results, which shows the high accuracy of the used numerical method. The adjustment of the wave energy converter based on the linear theory when it is affected by fast waves is not satisfactory at all. Also, the rate of reduction of tank turbulence under sloshing in the harmonic excitation mode is higher than in the linear excitation mode. The amount of fluid kinetic energy reduction in harmonic and linear excitation is 25% and 60%, respectively. Also, by increasing the cross section of the tank, the effectiveness of the wave energy converter increases in order to reduce the turbulence of the tank.