Design Of Air Gathering Hood And Numerical Analysis Of Wind Turbine Flow Field

Our country is rich in wind resources.Wind energy has the characteristics of renewable and clean.The use of wind energy has an irreplaceable role to solve the energy shortage.Nowadays,people utilize wind energy with the middle and huge horizontal axis wind turbine mainly.But this claim to wind speed when it starts and noise is louder.It can not work in low wind speed areas.In low wind speed areas such as near cities,people usually adopt H-type vertical axis wind turbine.It’s tip speed ratio is not high and startup characteristic slightly better.But comparing to other wind turbines,its use of energy is worse.In this paper,a scheme to improve the tip speed ratio and low wind speed start-up characteristics of H-type vertical axis wind turbine is proposed and further comparative analysis is made on the scheme.In this paper,firstly,the force theory and working mechanism of four blades in each quadrant are explained by using the knowledge of aerodynamics.Secondly,the numerical simulation method is used to simulate the real working situation of the wind turbine,and the corresponding aerodynamic parameters,such as torque,lift-drag ratio and power,are determined.Comparing with the scheme before and after adding the hood,it is shown that the scheme with the hood has more ideal aerodynamic parameters.The results show that adding a gas hood can improve the flow velocity of centralized pipe,wind power and wind energy utilization coefficient of the turbine.After adding the diffuser cover,the velocity ratio is increased and the efficiency of power generations is improved.At last,the design and analysis of the rectifying plate are carried out.The conclusion is that after adding a hood,the H-type vertical axis wind turbine has better adaptability in low wind speed areas.