Study On Optimization Design Method Of Wind Turbine Blade

Facing the extremely urgent energy and environmental crisis, wind, as the current renewable and clean energy, is already mature in commercial and scale development. There is an increasing attention in its development and usage all around the world. Wind generator is core of wind energy utilization, while the horizontal axis wind turbine is one of the main forms of wind turbines. Blade is the significant component of horizontal axis wind turbine, the wind energy conversion efficiency is closely related to the shape of wind turbine blade. That is to say, the technique of optimizing design with blade plays an important role in the design and manufacture of wind turbines.In this paper, the current research status, design theory and methods, blade efficiency, torque, force coefficient of wind turbine blade are analyzed both local and abroad. This study is based on the momentum—blade element theory and CFD method. A400KW wind turbine blades model are established. With aerodynamic calculation MATLAB programming, the efficiency values of turbine blades are acquired. Integrated blade airfoil thickness change impacts and variable pitch design requirements, a new optimized blade design method is proposed through Matlab program based on blade element-momentum theory. Take the annual average output power of each wind turbine blades as a optimized goal, the relative thickness of the airfoil and the pitch angle as design variable, using genetic algorithm optimization toolbox to optimize turbine blades with multi-parameter.In this paper, a new design method for the large wind blade turbine is proposed which can be separated into four stages:The first stage is to obtain the blade airfoil aerodynamic coefficients within the attack angle range -180～180°through combination of the software naca.exe, Xfoil and AirfoilPrep; The second stage is to set the basic parameters of the blades, such as rotor diameter, hub height, the tip speed ratio, leaf number and solidity through wind turbine blade design theory; The third stage starts with preliminary designed blade using the Wilson method. Iterative calculation procedures of blade efficiency is written by Matlab. With this, blade chord sections and twist angle are calculated, resulting in the efficiency of the initial value of the blade; The fourth stage is to get two sets of optimized blades. Using genetic algorithms to calculate the changes in the relative thickness of the blade individually through Wilson method design, finally to get the optimized blade parameters; At last, consider the impact of variable of blade thickness on the pitch angle, and then get the optimized parameters of the blade.The simulation results showed that the blade efficiency has increased at different wind speeds through the optimization method mentioned above and verified the practicality and effectiveness of the algorithm.This study mainly focus on airfoil aerodynamic coefficients of large attack angle. Based on changes in the relative thickness of the blade optimization method, and then proposed an optimal design method under the variation of relative blade thickness towards the pitch angle.