Simulation Study on the Effect of Vortex Generators on Dynamic Stall

doi:10.3901/JME.2019.24.203

Abstract

Abstract: The effects of vortex generators (VGs) on dynamic stall are investigated based on a blade segment using the airfoil of DU91-W2-250. The investigation is numerically performed by two simulation approaches, i.e. Delayed detached-eddy simulation (DDES) and k-ω SST, and their results are compared. The results show that of airflow separation and reattachment within the dynamic stall process are delayed on the smooth blade surface. After adding VGs, the airflow separation is delayed at the pitch up stage, the reattachment of air flow on the up surface becomes earlier when the blade is pitching down, and the aerodynamic hysteresis is obviously improved. The magnitudes of lift increased and the drag reduced by VGs of are substantial. In detail, the maximum lift coefficient of DU91-W2-250 blade segment is increased by 10%, the average value is increased by 17.9%; the maximum drag coefficient is decreased by 56.3%, and the average value is decreased by 40.3%. DDES model can demonstrate clearly the complex flow separation occurred in dynamic stall as it is under the effect of VGs, while the k-ω SST model hardly provides a deep insight into the small-scale vortices structure and which furthermore shows two-dimensional characteristics.

Key words: dynamic stall, vortex generator, DDES method, DU91-W2-250

CLC Number:

TK81

ZHAO Zhenzhou, SU Decheng, WANG Tongguang, WU Hao, MENG Lingyu, XU Bofeng, ZHENG Yuan. Simulation Study on the Effect of Vortex Generators on Dynamic Stall[J]. Journal of Mechanical Engineering, 2019, 55(24): 203-209.

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