Advertisement

The Effect of a Drooped Wing Tip on Its Trailing Vortex System

  • Barnes W. McCormick
  • Raghuveera Padakannaya
Conference paper

Abstract

The effect of wing tip droop on the structure and position of its trailing vortex is studied. Spanwise load distributions determined by vortex lattice theory show that the stronger vortex moves from the tip of the wing to the hinge of the drooped tip as the droop angle increases. Experimental results on model wings are given which present the strength and the induced velocity profiles of the rolled-up vortex as a function of tip geometry. These results confirm at least qualitatively, the analytical prediction. It is concluded that a droop angle of approximately 90° is optimum and results in a maximum induced velocity which is half of that produced by a plane wing.

Keywords

Control Point Horseshoe Vortex Vorticity Distribution Model Wing Helicopter Rotor 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Nomenclature

a

core radius where v(r) is a maximum

A

aspect ratio = b2/S

b

wing span

c

local wing chord

Cι

section lift coefficient

L

lift per unit span

r

radial coordinate

R

radius

s

semispan

S

wing area

v(r)

tangential velocity at radius r

vmax

maximum value of v(r) = v(a)

V

free stream velocity

W

downwash velocity

x, y, z

coordinates of the control point

y′

spanwise coordinate of the wing

X=x/yv

nondimensional coordinates of the control point

Y=y/yv

nondimensional coordinates of the control point

Z=z/yv

nondimensional coordinates of the control point

Z1

distance downstream of wing trailing edge

yv

semiwidth of the horseshoe vortex

θ

droop angle

α

angle of attack

Г(η)

circulation at the section η

η

y′/(b/2) nondimensional spanwise coordinate

ζ

vorticity at any radius r

ζmax

center value of ζ (r=0)

i, j

number of chordwise and spanwise locations of control points

ι, m

number of chordwise and spanwise locations of vortices

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    Padakannaya, R., “Effect of Wing Tip Configuration on the Strength and Position of a Rolled-up Vortex,” M. S. Thesis, 1970, The Pennsylvania State University, University Park, Pa.Google Scholar
  2. 2.
    Falkner, V. M., “The Calculations of Aerodynamic Loading on Surfaces of any Shape”, ARC, R & M No. 1910 (1941).Google Scholar
  3. 3.
    May, D. M., “The Development of a Vortex Meter,” M. S. Thesis, 1964, The Pennsylvania State University, University Park, Pa.Google Scholar
  4. 4.
    Falkner, V. M., “Calculated Loadings Due to Incidence of a Number of Straight and Swept-pack Wings”, ARC, R & M No. 2596 (1952).Google Scholar
  5. 5.
    McCormick, B. W., and Tangler, J. M., and Sherrieb, H. E., “Structure of Trailing Vortices,” Journal of Aircraft, May-June 1968, pp. 260–267.Google Scholar
  6. 6.
    Hoffman, E. R. and Joubert, P. N., “Turbulent Line Vortices”, Journal of Fluid Mechanics,“ Vol. 16, Pt. 3, July 63, pp. 395–411.CrossRefGoogle Scholar

Copyright information

© Plenum Press, New York 1971

Authors and Affiliations

  • Barnes W. McCormick
    • 1
  • Raghuveera Padakannaya
    • 1
  1. 1.The Pennsylvania State UniversityUSA

Personalised recommendations