23rd Congress of International Council of the Aeronautical Sciences, 8-13 September, 2002, Toronto, Canada
Paper ICAS 2002-R46

ON DESIGN OF UNCONVENTIONAL HIGH ASPECT RATIO "JOINED-WING" TYPE AIRCRAFT

R. K. Nangia (1), M. E. Palmer (1), C. P. Tilmann (2)
(1) Nangia Aero Research Associates, UK; (2) Wright-Patterson AFB, OHIO, USA

Keywords: joined wing aircraft, design, high aspect ratio

Unmanned Sensor Craft air vehicles have been proposed as the air-breathing component of a future intelligence, surveillance, and reconnaissance (ISR) infrastructure to provide revolutionary capabilities. Such craft must take advantage of high aspect ratio (AR) wings for aerodynamic efficiency, and may also be required to enclose an antenna in a diamond aircraft planform. A large proportion of fuel must be carried, and "loiter" is at high altitudes for a few days in each flight. This implies that a wide CL-altitude capability is required. This paper is concerned with aspects of configuration and design studies of high AR Sensor Craft. Implications of typical flight envelope on wing design aspects have been mentioned. Using Panel and Euler codes, results are presented for configurations with uncambered wing sections and then for configurations with designed camber and twist (trimmed for neutral stability). The designed case displays considerable reduction in LE suction, yet maintaining the lift, drag and near-elliptic wing loading characteristics. Results of an inverse design application are shown and further work is proposed in several areas.

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