Hostname: page-component-cb9f654ff-9knnw Total loading time: 0 Render date: 2025-09-01T10:11:05.362Z Has data issue: false hasContentIssue false
  • English
  • Français

On the effect of a strake-like junctionfillet on the lift and drag of awing

Published online by Cambridge University Press:  04 July 2016

L. Bernstein  and
S. Hamid
L. Bernstein
Affiliation:
Queen Mary and Westfield College , University of London
S. Hamid
Affiliation:
Queen Mary and Westfield College , University of London
Get access Rights & Permissions [Opens in a new window]

Summary

An experimental study of the effects on the low-speedaerodynamic characteristics of a strake-like filletis described, modelled on one used on an Airbus A320variant fitted at the leading edge of a sweptwing-plate junction. The wing, swept back at 20°,was of NACA 0015 section and chord 500 mm, bothnormal to its leading edge. A turbulent boundarylayer had developed on the plate well ahead of thejunction. The tests were conducted at a unitReynolds number of 1.56 x 106m-1.

Surface pressure distributions were measured on theplate in the neighbourhood of the leading edgejunction and also on the aerofoil and fillet at wingincidences of 0°, 3°, 6°, 9° and 12°. These weresupplemented by surface oil-flow studies.

The mean velocity and turbulence intensity fieldsaround the leading edge were examined for incidencesof 0° and 9°, using both a single tube yaw meterdeveloped for the purpose and an X-wire anemometer.The X-wire anemometer was also used downstream ofthe trailing edge of the swept wing; five of theReynolds stresses and the mean velocity field weremeasured.

The sectional lift coefficients on the aerofoil werefound to diminish as the junction was approached,slightly more so with the fillet than without it.The sectional drag coefficients due to pressureincreased as the junction was approached, the filletmoderating this increase to only a small extent.

However, the addition of the drooped fillet modifiedthe flow considerably. The horseshoe-like vortex wasless well defined than without it. At zeroincidence, the peak in the turbulence intensitylevels was virtually eliminated on what becameeffectively the compression side of the wing due tothe local camber introduced by the asymmetricfillet. The turbulence levels were also reduced bythe addition of the fillet at an incidence of 9°.However, the turbulent activity was spread through alarger proportion of the viscous region. Thesecondary flows and the turbulence activity in thewake are associated with unrecoverable kineticenergy and will be manifest as drag on the surfacesforming the junction.

It is concluded that a carefully designed fillet,optimised for the cruise incidence of an aircraft,can reduce the peak turbulence levels in thejunction. It remains unclear whether the total dragassociated with the junction flow can be reducedsignificantly.

However because of its effects on the turbulence, theremay be other benefits, for example on the efficiencyof downstream elements, such as fuselage-mountedengine intakes or the following stages of an axialflow machine. Junction fillets might also be used tocontrol the scouring of river beds around bridgepiers.

Information

Type
Research Article
Information
The Aeronautical Journal , Volume 100 , Issue 992 , February 1996 , pp. 39 - 52
Copyright
Copyright © Royal Aeronautical Society 1996 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Article purchase

Temporarily unavailable

Footnotes

*

Currently at DERA, Farnborough, UK

References

1. Barber, T.J. An investigation of strut-wall intersection losses, J Aircr, 1978, 15, pp 676–681.Google Scholar
2. Mehta, R.D. Effect of wing-nose shape on the flow in a wing-body junction, Aeronaut J, 1984, 88, pp 456–460.Google Scholar
3. Kubendran, L.R., McMahon, H.M. and Hubbartt, J.E. Turbulent flow around a wing/fuselage type juncture, AIAA J, 1986, 24, pp 1447–1452.Google Scholar
4. Rood, E.P. and Anthony, D.G. Tail profile effects on unsteady large-scale flow structure in the wing and plate junction, Forum on Unsteady Flow, (Ed) Rothe, P. H., ASME FGD 27, 1985.Google Scholar
5. Gough, M.L. The effect of fillets between wings and fuselages on the drag and propulsion efficiency of an airplane, NACA TN 299, 1928.Google Scholar
6. Hoerner, S.F. Aerodynamic Drag, Washington, DC, 1965.Google Scholar
7. Kubendran, L.R. and Harvey, W.D. Juncture flow control using leading edge fillets. AIAA Paper 85-4097. AIAA 3rd Applied Aero dynamics Conference, Colorado Springs, Colorado, 1985.Google Scholar
8. Maughmer, M., Hallman, D., Ruszkowski, R., Chappel, G. and Waitz, I. Experimental investigation of wing-fuselage integration geometries, J Aircr, 1989, 26, pp 705–711.Google Scholar
9. Sung, C-H., Yang, C-I. and Kubendran, L.R. Control of horseshoe vortex juncture flow using fillet, In: Proc of Symposium on Hydrodynamic Performance Enhancement for Marine Applications, Newport, RI, 1988.Google Scholar
10. Pierce, F.J., Frangistas, G.A. and Nelson, D.J. Geometry-modification effects on a junction-vortex flow. Proc. of Symp. on Hydrodynamic Performance Enhancement for Marine Applications, pp 37–44. Newport, RI, 1988.Google Scholar
11. Devenport, W.J., Agarwal, N K., Dewitz, M.B., Simpson, R.L. and Podder, K. Effects of a fillet on the flow past a wing-body junction, AIAA J, 1990, 28, pp 2017–2024.Google Scholar
12. Bernstein, L. and Hamid, S. On the effect of a swept wing-plate junction flow on the lift and drag, Aeronaut J, 1995, 99, (987), pp 293–305.Google Scholar
13. Bernstein, L. and Hamid, S. An experimental investigation of wing/body junction flows with and without a fillet. QMW EP-1095, 1993.Google Scholar
14. Chu, J.K., Rios-Chiquete, E., Sarohia, S.H. and Bernstein, L. The ‘Chu-tube’: a velocimeter for use in highly-sheared, three-dimensional steady flows, Aeronaut J, March 1987, 91, (903), pp 142–149.Google Scholar