科研之友
微信
新浪微博
Facebook
分享链接
摘要
Vortex-induced and stall-induced vibrations of a 2D elastically mounted airfoil at high angles of attack in the vicinity of 90 degrees are investigated using a vortex type model. Such conditions are encountered in parked or idling operation at extreme yaw angles provoked by control system failures. At very high angles of attack, massive flow separation takes place over the entire blade span, and vortex shedding evolves downstream of the blade giving rise to periodically varying loads at frequencies corresponding to the Strouhal number of the vortices shed in the wake. As a result, vortex-induced vibrations may occur when the shedding frequency matches the natural frequency of the blade. A vortex type model formulated on the basis of the double wake' concept is employed for the modelling of the stalled flow past a 2D airfoil. By tuning the core size of the vortex particles in the wake, the model predictions are successfully validated against averaged 2D measurements on a DU-96-W-180 airfoil at high angles of attack. In order to assess the energy fed to the airfoil by the aerodynamic loads, the behaviour under imposed sinusoidal edgewise motions is analysed for various oscillation frequencies and amplitudes. Moreover, stall-induced and vortex-induced vibrations of an elastically mounted airfoil section are assessed. The vortex model predicts higher aeroelastic damping as compared with that obtained using steady-state aerodynamics. Excessive combined vortex-induced and stall-induced edgewise vibrations are obtained beyond the wind speed of 30ms(-1).
- 出版日期2015-12
- 单位华中科技大学
