23rd Congress of International Council of the Aeronautical Sciences, 8-13 September, 2002, Toronto, Canada
Paper ICAS 2002-2.2.3

NUMERICAL PREDICTIONS OF WING-TIP EFFECTS ON LIFT-INDUCED DRAG

P. Bourdin
ONERA, France

Keywords: far field analysis, lift-induced drag reduction, wing-tip dihedral

This paper points out two small effects concerning lift-induced drag and wing-tip dihedral. To this end, a far field technique is used to extract drag from Euler computations. Numerical predictions show that at fixed projected span downward winglets produce less lift-induced drag than upward winglets of the same length. It is also found that at fixed winglet length, the minimum lift-induced drag is obtained with a little negative dihedral. These two effects are thought to be due to a better layout of the bound vorticity relative to the trailing vorticity.

view full paper