The Prediction Of Aerodynamic Performance On Straight-Bladed Wind Turbine

Wind power generation is to wind into electricity through the wind turbine device, so how to design an efficient and reliable wind turbine is the key to wind power generation technology. Compare with horizontal axis wind turbine, Vertical axis wind turbine has its advantage. In this paper, the research work on 600W straight blade vertical axis wind turbine, performs CFD analysis in the NACA series of symmetrical airfoils, simplified two-dimensional model of wind round and the full three-dimensional model. The main conclusions are as follows:First of all, different turbulence models such as k-ωSST,RNG k-εare used to simulate airfoil NACA0012, and the computational results are compared, the results show k-ωSST turbulence models are more useful for the simulation of airfoil NACA0012. The computational results of steady and unsteady are compared, the results show unsteady are more useful for the simulation of airfoil NACA0012.Secondly, without regard to rod, shaft, and the impact of the tip loss, simplified three-dimensional H-straight blade vertical axis wind turbines into two-dimensional wind round, using sliding grid numerical simulated the simplified model. The results show:For the same wind speed, as the wake away from the wind rotor, the wake velocity gradually closer to flow velocity; For the different wind speed, with the wind speed increases, the length of the wake-proliferation zone gradually increased, the minimum velocity of in wake spreading centers are also increasing; power as the wind speed increases, when the rated wind speed, the power values are also closer to the rated power; as the wind continued to increase, the power also increased; for the same rotational speed, as the wake away from the wind rotor, the wake velocity gradually closer to flow velocity; for the different rotational speed, with the rotational speed increases, the length in Y-direction of the wake-proliferation zone gradually increased; power as the speed increases, when it reaches a certain speed, the power reaches maximum, as the speed continues to increase, the power is gradually reduced; with the increase of speed power first increases and then decreases, the location of the maximum power of five blades is lower than the three leaves。Finally, the full three-dimensional unsteady flow of three-blade and five-blade wind turbines were analyzed in the different conditions based on N-S equation and SST turbulence model, using unstructured grids. Numerical simulation results show that using sliding grid-wide simulation of unsteady three-dimensional numerical calculation can be better to reflect the process of the wind wheel rotating flow field, the power curve and power coefficient curves of the change; Whether three or five blades blade wind wheel, all-round three-dimensional numerical simulation of wind power, power coefficient must be less than the two-dimensional numerical simulation of wind power wheel, power coefficient, mainly because full three-dimensional simulation takes into account the tip loss; the distribution of wake flow field is slightly different, but global change did not change significantly in a cycle of wind wheel rotation; Compared with the solidity, the influence of tip loss on five-blade is bigger than three-blade for this model。...