Research On Hydrodynamic Performance And Numerical Simulation Of Vertical Axis Tidal Current Turbine

With the energy and environmental issues becoming more prominent, it is necessary for human beings to look for development roads for the clean and sustainable energy. As one kind of clean and renewable energy, tidal current energy has attracted more and more attention all over the world, with its wide distribution, large reserves and no pollution.Tidal current turbine is the core equipment of the tidal current energy conversion. In this paper, the vertical axis tidal current turbine was used for the study and its hydrodynamic performance was studied. This study consists of two parts which are theoretical analysis and numerical simulation. Based on theoretical analysis, most work of this study has been accomplished by numerical simulation.First of all, the force of the blade and the turbine was analyzed. The theoretical models used for the calculation of the hydrodynamic performance of the turbine were described. Then, the basic theory of the numerical simulation was summarized. After the numerical models and methods had been discussed, the numerical solution steps were proposed. Secondly, after the physical model of the NACA0018airfoil at the large space had been established, the flow at different conditions was analyzed by the means of the steady numerical simulation. The flow characteristics at different angles of attack and different velocity were studied and the mechanism of airfoil stall was revealed. Finally, the two-dimensional and the three-dimensional physical model of the turbine in the sink were both established. Their flow field was respectively analyzed by means of the unsteady numerical simulation, by using sliding meshes. In the two-dimensional simulation, the influence of the parameters of velocity, number of blades, chord length, radius and airfoil on the hydrodynamic performance were studied. In the three-dimensional simulation, both the variation of the velocity field at different moments and the distribution of the velocity and pressure field at the same moment were analyzed.The flow of the turbine in the sink can be realistically simulated in this study and the influence law of the basic parameters of the turbine on its hydrodynamic performance can be obtained, which will be the foundation of the further experiment and the parameter optimization.