Published online by Cambridge University Press: 04 July 2016
Theoretical data from lifting-surface theory are presented to illustrate
(i) that the vortex drag factor is closely related to the half-wing spanwise centre of pressure on simple planforms without camber or twist,
(ii) that lifting-line theory is useless for predicting the spanwise distribution of vortex drag on swept wings,
(iii) that recent numerical improvements in lifting-surface theory help to reconcile the concepts of wake energy and leading-edge suction in relation to vortex drag.