| With the development of industrial modernization,the wind power industry,which is the most mature and promising technology of renewable energy,has been developed all over the world.The cost of wind power generation is also decreasing year by year.However,the cost of wind power is still an obstacle to the development of wind power industry,it is one of the important factors.In order to improve the efficiency of the wind turbine,thereby reducing the cost of wind power,it is necessary to optimize the design of wind turbine.The wind turbine blade is one of the most important parts of the wind turbine,the performance of wind turbine blade determines the ability to catch the wind and the service life of wind turbine.At present,domestic and foreign scholars have conducted extensive research on wind turbine blade optimization methods,the current blade has been optimized very well,and now simple wind turbine blade airfoil parameter optimization for the wind turbine to improve the ability to catch the wind has been ineffective,a new structure is needed to improve the wind-catching capability of the wind turbine.Among the many methods of structural retrofitting,the effect of adding separate trailing edge flap on the trailing edge of wind turbine is the most obvious and easy to realize,it can not only improve the aerodynamic performance of wind turbine gas,improve the ability to catch the wind,Which can not only improve the aerodynamic performance of the wind turbine,improve the ability of catching wind,but also can adjust and control the power and load of the wind turbine,can effectively improve the ability of catching wind at low wind speed and reduce the load of the wind turbine at high wind speed,it can also play an auxiliary pitch when the wind speed changes rapidly.It can reduce the operation and maintenance cost of the wind turbine and prolong the service life of the wind turbine while increasing the annual power output of the wind turbine.Therefore,it is very important to analyze and optimize the aerodynamic performance of wind turbine airfoil with separate trailing edge flaps.In this article,based on reading the relevant research literature of domestic and foreign,the horizontal wind turbine blade is taken as the research object,and the aerodynamic performance and optimization method of the two-dimensional wind turbine airfoil with separate trailing edge flap and three-dimensional wind turbine blade with separate trailing edge flap were studied systematically,The main research work includes:(1)Aerodynamic Calculation and Optimization Design Theory of Wind Turbine.The improved BEM theory,three-dimensional rotation effect model and various correction models are deeply studied and deduced.The Euler beam theory of composites is studied,and the coupling model of Euler beam theory and improved BEM theory is established.The turbulence model commonly used in computational fluid dynamics is also studied.(2)Aerodynamic Performance Analysis of Two Dimensional Airfoil with Separated Trailing Edge Flap.The airfoil S809 was taken as the research object,the model of the separate trailing edge flap of airfoil S809 was established,I used the SST model to carry out the numerical calculation and comparative analysis of the aerodynamic performance of the wind-wing type with trailing edge flaps,and compared the influence of different flap length,different flap deflection angle and different flap gap size on the aerodynamic performance of wind turbine airfoil.(3)Optimization of Flap Parameters Based on Support Vector Machine and Data Mining.Based on the aerodynamic performance data of flap wind turbine airfoil,the relationship between the flap parameters and the aerodynamic performance of the airfoil was established by using support vector machine data mining technology.The discrete aerodynamic performance numerical data were transformed into continuous numerical values.The function relationship between wing lift coefficient and flap deflection angle,flap length and airfoil flap width is respectively established,and the objective function of the flap parameter optimization with the maximum lift coefficient and the maximum lift-drag ratio weighted average is established,the flap parameters of the airfoil are optimized by using particle swarm optimization(PSO),the optimum flap parameters and corresponding aerodynamic performance of the airfoil are obtained,which laid the foundation for the optimal design and optimization of the three-dimensional blade with wind flaps.(4)Analysis of aerodynamic performance of three-dimensional wind turbine with flap.Based on the optimum flap parameters of the airfoil determined in the previous chapter,the geometric model of the flap with PhaseVI was established.The CFD method was used to calculate the aerodynamic performance.At the same time,the improved BEM theory was used to calculate and compare the aerodynamic performance.The results show that both the CFD method and the modified BEM theory can analyze the aerodynamic performance of the wind turbine with flap,and all have the same trend with the experimental value,and the error is within the allowable range.CFD can be used to further study the details of the flow field,and improved BEM theory can quickly calculate the aerodynamic performance of the wind turbine,taking up less computing resources.Compared with the wind turbine blades without flaps,it can be seen that the wind-driven capability of wind turbines with flaps is obviously enhanced.Especially at low wind speed,the starting wind speed of wind turbines is reduced from 5m/s to 3m/s.(5)Design and Optimization of Wind Turbine Blade with Flap.The commonly used design method of wind turbine blade is studied,600 kW wind turbine was designed by the improved BEM theory method and compared with the original wind turbine blades,which proves the rationality and reliability of the design method.On this basis,the optimal combination model of maximum annual power generation and cost of electricity is established,and the particle swarm optimization algorithm is used to optimize the model.The results show that when the weight is 0.5,the optimization result is larger than that of the original blade and the cost of electricity is reduced.The design and optimization of the 600 kW wind turbine with flaps were carried out on the basis of the results.The results show that the wind turbine with flaps greatly improves the wind catching ability at low wind speed and the rated wind speed is also reduced.Annual power generation increased by 10%,the cost of electricity decreased by 5%.Furthermore,the design and optimization of a 1.5MW variable speed variable propeller wind turbine with flap blades were also carried out.It is further verified that the trailing edge flap can improve the capture capability of variable pitch wind turbine in certain wind speed range,But the rate of increase of its effect on the fixed blade stall control wind turbine is not obvious.Through the optimization design of two kinds of blades of fixed speed and variable speed shows that the wind turbine with wind flaps can improve the ability to catch wind at low wind speed and reduce the load of wind turbine at high wind speed so as to prolong the wind power machine life. |
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