Exploiting Formation Flying for Fuel Saving Supersonic Oblique Wing Aircraft

摘要

Currently there is a great emphasis on fuel-efficient flight and this may be reflected in planned budgets and constraints for future. The idea of Close Formation Flying (CFF) to reduce drag and hence fuel usage, has been appreciated. A fair deal of theoretical and experimental work in subsonic flight is available. This report summarises theoretical analysis on a generic OFW planform in CFF at Mach 1.4. The analysis begins with an assessment of the planar (uncambered) OFW. Typical flight envelope parameters and design targets are established. Several design options are presented. The performance of the OFW, both planar and designed, in CFF is established and benefits, in terms of increased L/D throughout a range of formation geometries are determined. Results (trimmed for lift only at this stage) show up to 50% reduction in lift- induced drag of the trail aircraft. This implies 30-35% increases in lift-drag ratio and hence similar increases in range. Multiple aircraft formations reflect the benefits on all trailing aircraft. In view of the encouragement, further detailed work has been proposed in several areas.