Aerodynamics Load Calculation And Numerical Simulation Analysis Of Wind Turbine Blades Considering Tower Shadow Effects

With the energy problem increasingly outstanding, the wind energy has gainedincreasing attention. Therefore, there are more and more research carried out on thetechnology of wind power. On the process of operation, wind turbine’s performance is closelyrelated to the flow field. When the air runs through the wind rotor, the tower shadow effectmakes wind speed and direction change, and this impacts negatively on wind turbine’sperformance.In order to research the effect and regularity of tower shadow, taking downwind turbineas the research object, this paper calculated the aerodynamic loads on the blade, and studiedthe influence on the aerodynamic performance with tower. The main contents are as follows:1) Current status of the wind energy development at abroad and international waspresented, and downwind wind turbines characteristics were introduced. Besides, the loadcalculation of wind turbine and the tower shadow effect were reviewed.2) The aerodynamic theory of wind turbine and the basic principle of computational fluiddynamics (CFD) were briefly introduced. And this established the theoretical foundation forthe farther research.3) According to Glauert method, based on the parameters of10KW wind turbine blade,the spatial coordinates of blade were calculated by Matlab software. And aerodynamic loadscalculation mathematical model was derived according to the aerodynamics BEM theory.Then, the aerodynamic loads of10KW upwind and downwind wind turbine blades werecalculated, and the power change of blade rotor was analyzed.4) Based on the blade element（BEM）theory, the downwind wind generator wassimplified as a two-dimensional model of the tower and the blade section. Using Gambitsoftware, the model was computed. At different vertical distance between blade and tower, anumerical simulation of the model was founded in the Fluent software, and the pressurecoefficient change near the blade surface was found.5) Using the Pro/E software as the modeling tool, the three-dimensional flow model ofthe simplified downwind wind turbine was established, and it was imported to the ANSYSWorkbench for meshing. In the Fluent, firstly the steady numerical simulation was finished,then the blade surface static pressure and axial thrust without tower shadow were calculated;based on the theory of sliding mesh, the unsteady numerical simulation under the windturbines was carried out, and the effect of the rotation on the static pressure and the axialthrust of the blade were analyzed.