NACA-TN-1732

Abstract

A simple theory has been used to determine the effects of geometric dihedral angle on the rolling derivatives of swept wings. Equations and charts are given to show these effects. The analysis indicates that geometric dihedral has an appreciable effect on the lateral force due to rolling, that the damping in roll can be appreciably affected by geometric dihedral under some conditions, and that the yawing moment due to rolling is almost independent of geometric dihedral. The equations have been derived specifically for uptapered wings; however, the relations presented are believed to be reasonably reliable for wing of taper ratio as low as 0.5. <br>Some comparisons are made between calculated and experimental values of the rolling derivatives of an untapered 45&#186; sweptback wing of aspect ratio 2.61 having geometric dihedral angles from -20&#186; to 10&#186;. In general, good agreement between experimental and calculated results was obtained over the low- and moderate-lift-coefficient ranges.