Airfoil dynamic stall research of wind turbine

Abstract

This paper, based on the reduced version of Beddoes-Leishman dynamic stall model, makes deeply research about airfoil dynamic stall for wind turbines. Considering about the operating environment of wind turbine, the model, constructed in this paper, neglects the compressibility of airflow, and mainly considers attached flow, trailing edge separation and vortex lift. This paper uses fourth-order Runge-Kutta method to solve the differential equations of four state variables, and research the characteristics of dynamic lift coefficients by changing the average angle of attack, reduced frequency and value of time constants. The result shows that when the variable range of angle of attack locates in the region of slightly stall, the maximum of dynamic lift coefficient increases about 53.5%, compared with the maximum of static lift coefficient. And with the reduced frequent k inceasing from 0.05 to 0.15, the reattached angle of attack increases from 4.7° to 12.5°, this indicates increasing the pitch rate can restrain the airflow separation of airfoil surface. And through changing the value of time constants in this model, the maximum of dynamic lift coefficient and dynamic stall angle of attack can be adjusted so that the result of simulation can be more consistent with experimental data.