An aerodynamic comparison of planar and non-planar outboard wing planforms

An investigation of seven different configurations for two different spans confirms that an experimentally derived span efficiency of greater than one is possible for a nonplanar wing. It is suggested that the induced drag benefits of wings with nonplanar outboard planforms relate to the movement of vorticity away from the center of the span line. Both the position of the vortex and its effect on the wing's downwash distribution are found to significantly effect nonplanar wing performance.