Patent attributes
An adjustable size inlet duct system for a ducted fan propulsion system may change its inlet profile to enhance thrust levels in low-speed and hovering flight conditions and may change its inlet profile to reduce drag to permit faster flight speeds at higher operating speeds. The adjustable size inlet duct system may include duct petals and associated actuators. During slow speed flight, the petals may expand to generate a rounded large inlet area bellmouth profile. At higher flight speeds, the petals may contract to reduce the profile drag of the duct in forward flight. An optional exterior bypass duct may be included to provide additional thrust in excess of the thrust provided by the ducted fan. An optional annular electric motor housed in the exterior bypass duct may be included to generate still more excess thrust.
