0
research-article

Effect of a single leading-edge protuberance on NACA 634-021 airfoil performance

[+] Author and Article Information
Chang Cai

State Key Laboratory of Hydroscience and Engineering, Department of Thermal Engineering, Tsinghua University, Beijing 100084, China
cai-c12@mails.tsinghua.edu.cn

Zhigang Zuo

State Key Laboratory of Hydroscience and Engineering, Department of Thermal Engineering, Tsinghua University, Beijing 100084, China
zhigang200@mail.tsinghua.edu.cn

Shuhong Liu

ASME Membership, State Key Laboratory of Hydroscience and Engineering, Department of Thermal Engineering, Tsinghua University, Beijing 100084, China
liushuhong@mail.tsinghua.edu.cn

Takao Maeda

Division of Mechanical Engineering, Mie University, Tsu, Mie 514-8507, Japan
maeda@mach.mie-u.ac.jp

1Corresponding author.

ASME doi:10.1115/1.4037980 History: Received August 04, 2016; Revised April 03, 2017

Abstract

Leading-edge protuberances on airfoils or wings have been considered as a viable passive control method for flow separation. In this paper, the aerodynamic performance of a modified airfoil with a single leading-edge protuberance was investigated and compared with the baseline NACA 634-021 airfoil. Spalart-Allmaras turbulence model was applied for the numerical simulation. Compared to the sharp decline of baseline lift coefficient, the stall angle of the modified foil decreased and the decline of the lift coefficient became mild. The post-stall performance of the modified airfoil was improved, while the pre-stall performance was declined. Asymmetric flows along the spanwise direction were observed on the modified airfoil, and the local region around one shoulder of the protuberance suffered from leading edge separation at pre-stall angles of attack, which may be responsible for the performance decline. At post-stall angles of attack, the attached flows along the peak of the protuberance with a sideward velocity component, would help improving the total performance of the airfoil. Experimental visualization methods, including surface tuft and smoke flow, were performed, and the asymmetric flow pattern past the protuberance was successfully captured. This specific phenomenon may be largely related to the formation of the bi-periodic condition and other complicated flow patterns induced by multiple leading-edge protuberances. The formation mechanism and suppression method of the symmetry breaking phenomenon should be investigated more deeply in the future to guide the practical application of this passive control method.

Copyright (c) 2017 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In