| The calculation for the aerodynamic characteristics of wind turbine blades is the key of wind turbine design technology, which supplies the aerodynamic estimation and feedback of the aerodynamic design and the original data of the aerodynamic loads for the structure design of blades. The accuracy of the calculation directly influences the aerodynamic characteristics and structural safety ,then the work efficiency and longevity of the wind turbine is also affected.Based on the classical blade element momentum (BEM) theory, a calculation method for the aerodynamic characteristics of wind turbine blades is founded in this paper. Tip-loss model ,hub-loss model and Glauert correction is introduced into this model, so as to make it suitable for the calculation of aerodynamic characteristics of wind turbine blades. Aim at the handling of the dynamic stall events in the unsteady condition, coupled with the modified BEM model ,Beddoes—Leishman dynamic stall model is referred to ,so a calculation model is founded, and the time dependent aerodynamic dynamic characteristics for example normal force ,tangential force and pitch moment is calculated accordingly.With the help of model founded previously, aerodynamic parameters of wind turbine blades in the steady and unsteady cases are resolved. Compared with the experimental data, we can come to the conclusion that the newly founded the model can predict the aerodynamic characteristics of blades exactly. Due to the fastness and the accuracy of the calculation, this model is considered to be of great value for the application.In addition, through the analysis of the calculation results, the following facts can be inferred: The prediction of the performances of tip and hub of blades need to be improved; The three-dimensional rotational effect is obvious, especially under the unsteady condition, which need some consideration; There are some limits in the B—L model for the calculation of unsteady condition, so some improvements need to be made.
|
PDF Full Text Request