Calculation Of Aeroelastics And Dynamic Responses Of Wind Turbine

Large scale wind turbines work in complex conditions，which contains all kinds of unsteady andcoupling effects, so it is very difficult to predict the performance accurately. Combining aerodynamic,structural and other subjects, taking the coupling effects into account sufficiently, and applying themethod to the design process to improve the performance’s calculation accuracy and design level ofwind turbine, have important significance.According to the different stages of design process of the wind turbine, the building and solvingmethod of the coupled aerodynamic and structural model, the effect of aeroelastic, and theirapplication on wind turbine design are studied in this paper.In the preliminary design stage, the static aeroelastic effect on wind turbine blade is introduced,where a static aeroelastic balancing coupling equation is built. The blade element momentum methodis utilized to calculate the aerodynamic forces and moments, and the multi-cell beams method isadopted to calculate the structural distortion. The loads on the blade and the aerodynamic performanceof the rotor at various wind speeds are calculated using this method. The influence of elasticdeformation on the aerodynamic design and the influence of loads redistribution on the bladestructural design are analyzed.In the detailed design and checking stages, the dynamic situations of the wind turbine operationprocess are investigated. The unsteady blade element momentum method is used to calculate theaerodynamic loads. The effect of centrifugal force is taken into account to obtain the dynamiccharacteristics of rotating flap/edgewise coupled blade. The aerodynamic damping and the modesuperposition method are also used to build the coupled dynamics equations of blade, which can besolved by the numerical method. Based on these, the finite element method is used to build the wholewind turbine structural dynamic model. Combined with the above methods, the equations ofaerodynamic/structural coupled system of wind turbine are established. With the models, the dynamiccharacteristics with the centrifugal force and the dynamic loads in different conditions as well as theaeroelastic responses of the wind turbine main components are calculated. The calculated results arecompared with those from commercial software, and multiple influences of aeroelastics on the windturbine performance and design are also analyzed.