Aerodynamic Shape Optimization Design Of Large Scale Wind Turbine Blade

The blade is the core component of wind turbine which accounts for about20%ofthe whole cost. The aerodynamic shape of the blade directly affects the ability of windenergy capture of the wind turbine, and it plays an important role in the design of windturbine machine.The study on aerodynamic shape design of the blade is still less in ourcountry. Therefore, the research will have a positive significance on designing theblade shape of wind turbine to the development of China’s wind power industry.In this thesis, the aerodynamic shape design of the blade wind turbine is studied, themain contents are as follows:The basic theory of wind turbine blade, such as Momentum theory, blade elementtheory, vasopressin-Momentum (BEM) theory are introduced. Based on the basicaerodynamic design method of blades, include Glauert method and Wilson method areintroduced. The MATLAB theoretical calculation model of vasopressin-Momentum(BEM) is finished, the Ruweiersen method empirical formula is introduced to correctthe axial induction factor.A new design idea of blade aerodynamic shape is proposed. Based on the initialdesign parameters of the blade, a method of quadratic function to control the bladechord length distribution and the distribution of twist angle along its span is proposed,the parametric expressions of airfoil distribution is established.the optimization resultis obtained to iterative the corresponding variables of geometrical shape, it will shortenthe design cycle and improve the design quality. After optimization the2MW blade,the rated wind speed is10.35m/s, it decrease about5.9%; the power of wind turbine is2.368MW when wind speed is11m/s, the power improved to18.4%beforeoptimization. The optimization of wind turbine operating characteristics is analyzed,and the relationship between wind speed and speed, the relationship between windspeed and blade pitch angle, the relationship between wind speed and wind turbinepower is obtained.According to the parameter optimization of blade shape, the solid model of blade isestablished by using the software of Pro/E. The meshing and the boundary conditionsof wind field model is finished by using the software of Gambit. The grid file isimported into the commercial CFD software of Fluent in SIMPLE algorithm, thecriteria turbulence model is selected, The flow velocity vector diagram, pressure cloud diagram and air flow trajectories diagram is obtained. The simulation and theoreticalcalculations of rotor diameter of16m、20m and28m are compared. The errors were1.7%、5.9%and6.9%, the result shows that it can predict the simulation of powerwheel rectification is match with the theoretical design.