Variable-geometry ducted fan

An aircraft comprising:

• a vehicle body;
• and
• at least one variable-geometry ducted fan coupled to said vehicle body, wherein said variable-geometry ducted fan is rotatable between an approximately vertical orientation and an approximately horizontal orientation, and wherein said variable-geometry ducted fan comprises:
• an air duct having a longitudinal axis, said air duct comprising an inlet of said variable-geometry ducted fan;
• a fan rotatably mounted within said air duct downstream from said inlet, said fan comprising fan blades defining a fan area;
• a variable-area nozzle coupled to said air duct downstream from said fan, said variable-area nozzle comprising an exhaust of said variable-geometry ducted fan having a variable exhaust area, wherein said variable-area nozzle comprises a circumferential array of pedals,
• wherein a first pedal of the circumferential array of pedals comprises a first inner skin and a first outer skin, wherein said first pedal includes a first moment arm rigidly coupled between said first inner skin and said first outer skin and a first ring fitting coupled to said first moment arm, said first ring fitting encircling an first opening,
• wherein a second pedal of the circumferential array of pedals comprises a second inner skin and a second outer skin, wherein said second pedal includes a second moment arm rigidly coupled between said second inner skin and said second outer skin and a second ring fitting coupled to said second moment arm, said second ring fitting encircling a second opening;
• and
• an actuation system, said actuation system comprising:
• an actuator ring passing through said first opening and through said second opening, wherein said actuator ring extends circumferentially around said variable-area nozzle, wherein expansion of said actuator ring expands said variable-area nozzle and contraction of said actuator ring contracts said variable-area nozzle;
• and an actuator that drives expansion and contraction of said actuator ring.

A method comprising:

• positioning a variable-geometry ducted fan in one of an approximately vertical orientation or an approximately horizontal orientation, said variable-geometry ducted fan comprising:
• an air duct comprising an inlet of said variable-geometry ducted fan;
• a fan rotatably mounted within said air duct downstream from said inlet;
• a variable-area nozzle coupled to said air duct downstream from said fan and comprising an exhaust of said variable-geometry ducted fan, wherein said variable-area nozzle comprises a circumferential array of pedals, wherein a first pedal of the circumferential array of pedals comprises a first inner skin and a first outer skin, wherein said first pedal includes a first moment arm rigidly coupled between said first inner skin and said first outer skin and a first ring fitting coupled to said first moment arm, said first ring fitting encircling an first opening, wherein a second pedal of the circumferential array of pedals comprises a second inner skin and a second outer skin, wherein said second pedal includes a second moment arm rigidly coupled between said second inner skin and said second outer skin and a second ring fitting coupled to said second moment arm, said second ring fitting encircling a second opening;
• and
• an actuation system, said actuation system comprising:
• an actuator ring passing through said first opening and through said second opening, wherein said actuator ring extends circumferentially around said variable-area nozzle, wherein expansion of said actuator ring expands said variable-area nozzle and contraction of said actuator ring contracts said variable-area nozzle;
• and an actuator that drives expansion and contraction of said actuator ring;
• one of:
• expanding said variable-area nozzle relative to a longitudinal axis of said variable-geometry ducted fan to increase an exhaust area of said exhaust when said variable-geometry ducted fan is in said approximately vertical orientation for vertical flight;
• or
• contracting said variable-area nozzle relative to said longitudinal axis of said variable-geometry ducted fan to decrease said exhaust area of said exhaust when said variable-geometry ducted fan is in said approximately horizontal orientation for horizontal flight;
• drawing air into said variable-geometry ducted fan through said inlet;
• moving said air through said variable-area nozzle;
• and
• exiting said air from said variable-geometry ducted fan through said exhaust to generate thrust suitable to enable one of said vertical flight or said horizontal flight depending upon said orientation of said variable-geometry ducted fan.