0
Research Papers: Multiphase Flows

Winglet Dihedral Effect on Flow Behavior and Aerodynamic Performance of NACA0012 Wings

[+] Author and Article Information
Shun C. Yen1

Associate Professor e-mail: scyen@mail.ntou.edu.tw Graduate Student Department of Mechanical and Mechatronic Engineering, National Taiwan Ocean University, Keelung, Taiwan 202, Republic of China

Yu F. Fei

Associate Professor e-mail: scyen@mail.ntou.edu.tw Graduate Student Department of Mechanical and Mechatronic Engineering, National Taiwan Ocean University, Keelung, Taiwan 202, Republic of China

1

Corresponding author.

J. Fluids Eng 133(7), 071302 (Jul 22, 2011) (9 pages) doi:10.1115/1.4004420 History: Received July 01, 2010; Accepted June 10, 2011; Published July 22, 2011; Online July 22, 2011

This study investigates the effects of Reynolds number, angle of attack, and winglet dihedral (δ) on the smoke-streak flow patterns, surface oil-flow configurations, and aerodynamic performance of the wingleted wings. The airfoil is NACA 0012 and the winglet dihedral varies from −30° to 135°. The smoke-wire technique was utilized to visualize the three-dimensional flow structures. Furthermore, the effect of δ on the wingtip surface vortex was examined using the surface oil-flow scheme. The wingtip surface vortex was observed on a baseline wing using the smoke-streak flow and surface-oil flow visualization schemes. Moreover, the length of wingtip surface vortex (Lb ) decreases with increasing δ for δ > 15° where Lb denotes the major axis of wingtip surface vortex. The maximum Lb /C of 1.2 occurs at δ = 15° which is about 42% higher than that of a baseline wing, where C represents the wing chord length. The high flow momentum expands the wingtip surface vortex toward the winglet when δ < 15°. However, the minimum Lb /C of 0.55 occurs at δ = 90° which is about 34% lower than that of a baseline wing because the wingtip surface vortex is squeezed intensely at high δ. The aerodynamic performance was measured using a force-moment balance. The experimental data indicates that the lift-drag ratio at stalling (CL /CD )stall and maximum lift-drag ratio (CL /CD )max occurs at δ = 90°.

FIGURES IN THIS ARTICLE
<>
Copyright © 2011 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 2

Profile view of smoke-streak flow patterns around a baseline wing at Re = 9000. (a) and (b) at y/C = 5.0, near wing tip; (c) and (d) at y/C = 2.5, at midwing semispan; (e) and (f) at y/C = 0.5, near wing junction.

Grahic Jump Location
Figure 3

Profile view of smoke-streak flow patterns near the wingleted wing tip at Re = 9000. (a)–(d) δ = 15°; (e)–(h) δ = 30°; (i)–(l) δ = 90°.

Grahic Jump Location
Figure 4

Planform view of smoke-streak flow patterns around a baseline wing tip at Re = 9000. (a) α = 0°, (b) α = 10°, (c) α = 15°, and (d) α = 30°.

Grahic Jump Location
Figure 5

Surface oil-flow patterns on a baseline wing and wingleted wings (δ = 15°–90°) at (a) α = 0° and (b) α = 15° when Re = 8.0 × 104

Grahic Jump Location
Figure 6

Hand sketches of boundary-layer flow patterns corresponding to Fig. 5

Grahic Jump Location
Figure 7

Variation of Lb /C versus δ at Re = 8.0 × 104

Grahic Jump Location
Figure 8

Distributions of lift coefficient (CL ), drag coefficient (CD ), and lift-drag ratio (CL /CD ) versus angle of attack (α) for (a)–(c) baseline wing and (d)–(f) δ = 30° when Re = 8.0 × 104

Grahic Jump Location
Figure 9

Distributions of (a) lift coefficient (CL ), (b) drag coefficient (CD ), and (c) lift-drag ratio (CL /CD ) against angle of attack (α) at Re = 8.0 × 104

Grahic Jump Location
Figure 10

Variation of lift-drag-ratio change rate (η) versus angle of attack (α) at Re = 8.0 × 104

Grahic Jump Location
Figure 11

Distributions of (a) stall angle of attack (αstall ), (b) stall lift coefficient (CL stall ), and (c) stall drag coefficient (CD stall ) against the winglet dihedral (δ)

Grahic Jump Location
Figure 12

Distributions of stall point lift-drag ratio (CL /CD )stall and maximum lift-drag ratio (CL /CD )max against winglet dihedral (δ)

Grahic Jump Location
Figure 1

Experimental setup

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