Numerical Investigation of Three-Dimensional and Vortical Flow Phenomena to Enhance the Power Performance of a Wind Turbine Blade

Abstract

The performance of a wind turbine generator (WTG) is highly dependent on the interaction of a rotor blade with complex fluid behaviors, especially the induced vortex structure. In this paper, vortical flows around a blade were first investigated by the unsteady Reynolds averaged Navier–Stokes (RANS) simulation with shear stress transport (SST) turbulence model. It showed that the vortical flows were strongly formed at the blade tip due to the 3D behavior of the boundary layers dominated by pressure gradient. The strong secondary flow was also formed at the near hub due to the Coriolis force and the centrifugal force. At the interacting region of the rotating blade with the tower, the power production was reduced by 22.1% due to the high-pressure fluctuation of the 3P frequency. Based on the close investigation, methods for enhancing the power performance of a WTG were explored, which included the optimization of winglet and ogee design for the blade tip and optimal layout of the nacelle anemometer. The optimized winglet achieved the increase of aerodynamic performance with 0.54%, and the optimal location of the nacelle anemometer was found with a low-turbulence intensity level of 0.003 normalized by the rotor tip speed. The results showed that the traditional anemometer needs to consider the intrinsic flow angle of 11.43° to avoid the loss of aerodynamic performance caused from yaw error.

Current state and future trends in boundary layer control on lifting surfaces

“…59 This form (although any other shape and arrangement is also possible) is most often employed on the root sections of large-scale wind turbine blades to mitigate the effects of flow separation. Given the importance of the topic, a truly great number of both experimental [60][61][62][63] and numerical [64][65][66][67][68][69][70][71] research studies is available. Different VGs are experimentally explored by Zhang et al 60 The results show that the maximum lift coefficient increases with VGs installed toward the leading edge of airfoils.…”

Wind Field Characteristics of Butte and the Influence on the Wind-Induced Responses of Transmission Towers

“…Huang et al [16] used a hybrid numerical simulation method to predict the typhoon wind field over complex terrain; they found that, after taking the effect of topography into account, the hybrid numerical simulation method can give a better prediction of the hourly mean wind speed and direction. To make full use of mountain environmental resources, in recent years, the efficient combination of geotechnical engineering design [17][18][19][20] and related mountain construction projects has further enhanced the complexity of the mountain environment where the transmission tower is located [21][22][23][24][25]. Based on the actual environmental conditions of undulating terrain, it is necessary to fully study the impact of external actual soil and mountains on the wind site of the transmission tower.…”