Structure Optimization And Numerical Simulation Of Vertical-axis Ocean Current Turbine

Ocean currents can be used as a green renewable energy, which has more incomparable advantages than conventional energy. This paper describes the causes of ocean currents and the study status .The velocity analysis and the stress analysis of the vertical-axis ocean currents turbine are analyzed. Based on the above analysis, the working principle about the variable pitch and an initial program are presented. Through the analysis of experimental verification, we find that the program can improve the hydrodynamic performance of the vertical axis ocean currents turbine.On the basis of "single disk - single-stream tube" of vertical-axis wind turbine model, the mathematical model about the vertical-axis ocean currents turbine is established. Program is made by the C language combined with numerical integration methods, and the key parameters of the vertical-axis ocean currents turbine are analyzed. The results show that the model can provide the performance predictions of vertical-axis ocean currents turbine. The number of blades is more, the start-up performance is better. The greater chord length of the vertical-axis ocean currents turbine has higher energy efficiency and better start-up performance. In the case of the same tip speed ratios, the radius of the larger vertical-axis ocean currents turbine is better than the smaller one on the power and torque. Large density of the vertical-axis ocean currents turbine is better than the small one on the performance of start-up.The airfoil affecting on the performance of vertical axis ocean currents turbine is studied and the two-dimensional flow field is simulated by FLUENT, and the velocity field and the pressure field are analyzed, and the analysis can provide the forecasts and guidance to the actual design and installation. Research shows that-the symmetrical airfoils which are big lift have good effect on the working flow field, which is stable and orderly; and there is a certain periodicity about the working flow field of the vertical axis ocean currents turbine, and disturbance is more intense inside the rotor and the tail of rotor.