Study On Wind Turbine Blade Integrated Parametric Design Theory And Aerodynamic Performance Analysis Of DAWT

With the increasingly serious energy and environmental problems,more and more attention was paid to the research of new energy sources.One of the most ancient renewable energy on earth the wind has the advantages of large amount of reserves and wide distribution.High performance modern wind turbines can reduce the power cost,therefore in order to chieve this goal a wind turbine airfoil,blade and augment diffuser collaborative design method is proposed,as well as the parametric expression,design and analysis theory of wind turbine was studied.For the realization of three dimensional parametric design and modeling of wind turbine blades the hybrid parametric mathematical model was established which contains airfoil profile,chord and twist angle distribution.The chord and twist angle distribution is parameterized and modified by the airfoil integrated parameterization theory which is coupled with Bezier curve,therefore a more smooth wind turbine blade shape is obtained.The optimal value of the shape function parameter of the airfoil is solved iteratively,when the standard deviation of fitting and original airfoil is minimum.Taking the parametric modeling of a small wind turbine blades by 58 parameters as an example shows that corresponding wind turbine of control parameters are in good agreement with the original one in terms of power,load and noise,and at the same time it meets the requirement of convergence precision,furthermore it also provides theoretical basis for the collaborative optimization design of the wind turbine blade.A multi objective optimization design method is proposed for multi-working points in order to get the special wind turbine airfoil with good aerodynamic performance and low noise level.Each airfoil optimization model and solution method are established based on the special requirements for different parts of the blade,and then a set of wind turbine special airfoils are designed with high aerodynamic performance and low noise level for the small wind turbine blade under the low wind speed conditions,Improving the power coefficient of wind turbine is one of key technologys to reduce the power cost,so a design method is presented for Diffuser Augment Wind Turbine mechanism and its operating characteristics.Based on computational fluid dynamics and BEM theory,a unified aerodynamic performance calculation model is derived for the traditional wind turbine and diffuser augment wind turbine.A small and high performance Diffuser Augment Wind Turbine is obtained by the collaborative configuration of airfoil,diffuser,blade number and pitch angle.The start-up wind speed of the new diffuser augment wind turbine is reduced through the design of it,and meanwhile the annual power output of the new type one is 1.96 times of the same size traditional wind turbine blades.