EFFECT OF SERRATED GURNEY FLAP ON NACA0018 AIRFOIL WAKE WITH LIUTEX IDENTIFICATION METHOD

Yu Yongdi; Chen Liu; Zheng Zhehui; Dai Ren

doi:10.19912/j.0254-0096.tynxb.2021-0343

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Acta Energiae Solaris Sinica ›› 2022, Vol. 43 ›› Issue (10) : 210-217. DOI: 10.19912/j.0254-0096.tynxb.2021-0343

EFFECT OF SERRATED GURNEY FLAP ON NACA0018 AIRFOIL WAKE WITH LIUTEX IDENTIFICATION METHOD

Yu Yongdi¹, Chen Liu^1,2, Zheng Zhehui¹, Dai Ren¹

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Abstract

The wake flow of a NACA0018 airfoil is analyzed at the Reynolds number of 1.38×10⁵ in a wind tunnel experiment to investigate the effect of a serrated Gurney flap. The wake structures of a serrated flap and a conventional fully spanned flap are compared to elucidate the flow control mechanism of serrated flap. Results show that the wake loss due to velocity deficit is obviously lower for the serrated flap at a small attack angle while the flow deflection gets reduced. A pair of counter-vortex is found with the Liutex identification method in the flow through the serrated flap, which gets mixed dissipation with the inherent streamwise vortex generated by the flap. It reduces the wake instability caused by the streamwise vortex and hence the resistance of the airfoil. Comparison of the flow at different tooth positions near the trailing edge shows an increase of velocity deviation angle from the tooth root to tip, For the far-field wake, the flow of the three sections is consistent.

Key words

wind turbines / flow control / vortex / serrated Gurney flap / Liutex

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Yu Yongdi, Chen Liu, Zheng Zhehui, Dai Ren. EFFECT OF SERRATED GURNEY FLAP ON NACA0018 AIRFOIL WAKE WITH LIUTEX IDENTIFICATION METHOD[J]. Acta Energiae Solaris Sinica. 2022, 43(10): 210-217 https://doi.org/10.19912/j.0254-0096.tynxb.2021-0343

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