Study On Aeroelasticity Of Horizontal Axis Wind Turbine Based On Multibody Dynamics Theory

The modern blade becomes more large and flexible with bending-twist shape. Therefore, it's natural coupling dynamics becomes more complex, and more serious coupling with wind turbine, that will cause aeroelastic damage more easily. So the wind turbine aeroelastic research is very important. A new finite element model is established to study the natural coupling mechanism of bending-twist blade. And then, a new multibody dynamics model is built for aeroelastic analysis based on the the mechanism. The following research works have been finished.Firstly, aerodynamic program is written on the study of BEM theory and its correction algorithm. The advantages and disadvantages are compared on the induced factor algorithm. The results show that different algorithm has great influence on BEM computation. Then a new algorithm for induced factor is developed. With comparison to the experiment, this new algorithm is more accurate. This will help the next aeroelastic computation.Secondly, A new finite element model is established according to the bending-twist shape with special curved beam theory. And then, the coupling character of a1.5MW blade is studied. Compared to straight beam theory, the results show that twist mode has been appeared in low frequency, and this make the coupling deflection of flap,edgewise and twist. Therefore the twist factor must be accounted for aeroelastic simulation.Thirdly, According to the above conclusion, a new multibody dynamics model is built with spherical hinge. Aeroelastic response of the1.5MW blade is simulated with aerodynamics from BEM program. The results show that the coupling response deflection is more serious for the twist deflection. That makes the flap response reduce and edgewise response increase. And this is advantageous for bending design. Also, this is the base of the wind turbine model.The fourth, accounting for twist deflection, the wind turbine multidynamics model is established based on the above blade model. The aeroelastic simulation results show that, for the example in this paper, with stable wind, torsional deformation cause leaf root waving pendulum vibration reduced, smaller tower response without yaw and pitch control. This has reference value for wind turbine design.The last, the full-scale blade experiment is done with the test bench built by Institute of Engineering Thermophysics and Baoding national new energy base. The results verify the above curved blade theory.