Subsonic Vortex-Flow Design Study for Slender Wings

A theoretical study describing the effects of spanwise camber on the lift dependent drag of slender delta wings having leading-edge vortex flow is presented. The earlier work by Barsby, using conical flow, indicated that drag levels similar to those in attached flow could be obtained. This is re-examined and then extended to the more practical case of nonconical flow by application of the vortex-lattice method coupled with the suction analogy and the recently developed Boeing free-vortex-sheet method. Lastly, a design code is introduced which employs the suction analogy in an attempt to define "optimum" camber surfaces for minimum lift dependent drag for vortex flow conditions.