The joined-wing airplane employs two sets of wings rigidly connected together to form a triangulated, self-bracing structure. Structural analyses and wind-tunnel tests have shown that, compared to cantilever-wing aircraft, joined-wing aircraft are lighter and stiffer and have lower induced drag. The joined wing also permits thinner airfoils to be used, thus increasing the Mach Number for drag divergence and the maximum speed. Applied to tilt-rotor aircraft, in addition to the advantages cited, the joined wing may reduce adverse downwash effects in hover. This project will delineate joined-wing, tilt-rotor configurations that give maximum increases in performance. It will compare the performance and aeroelastic characteristics of joined-wing versus cantilever configurations and outline detailed analyses and tests which will provide a data base for design of joined-wing, tilt-rotor aircraft.
Potential Commercial Applications:This project may lead to performance improvements for military and civil tilt-rotor aircraft which will combine the hover capability of helicopters with the cruise speed of fixed-wing aircraft.STATUS: Phase I Only
