Sounds are generated by an aerial vehicle during operation. For example, the motors and propellers of an aerial vehicle generate sounds during operation. Disclosed are systems, methods, and apparatus for actively adjusting the position and/or configuration of one or more propeller blades of a propulsion mechanism to generate different sounds and/or lifting forces from the propulsion mechanism.

This disclosure describes aerial vehicles and systems for altering the noise generated by the rotation of a propeller during flight of the aerial vehicle. In some implementations, propellers of the aerial vehicle are paired in a coaxially aligned configuration in which the pair of propellers both rotate in the same direction, are rotationally phase aligned, and separated a defined distance so that the noise from high pressure pulse of the induced flow from the lower propeller is at least partially canceled out by the noise of the high pressure pulse of the induced flow from the upper propeller.

This disclosure describes aerial vehicles and systems for altering the noise generated by the rotation of a propeller during flight of the aerial vehicle. In some implementations, propellers of the aerial vehicle are paired in a coaxially aligned configuration in which the pair of propellers both rotate in the same direction, are rotationally phase aligned, and separated a defined distance so that the noise from high pressure pulse of the induced flow from the lower propeller is at least partially canceled out by the noise of the high pressure pulse of the induced flow from the upper propeller.

Sounds are generated by an aerial vehicle during operation. For example, the motors and propellers of an aerial vehicle generate sounds during operation. Disclosed are systems, methods, and apparatus for actively adjusting the position and/or configuration of one or more propeller blades of a propulsion mechanism to generate different sounds and/or lifting forces from the propulsion mechanism.

An axial flow turbomachine (102) for producing thrust to propel an aircraft is shown. The turbomachine has an inner duct (202) and an outer duct (204), both of which are annular and concentric with one another. An inner fan (206) is located in the inner duct, and is configured to produce a primary pressurised flow (P). An outer fan (207) is located in an outer duct, and is configured to produce a secondary pressurised flow (S). The outer fan has a hollow hub (208) through which the inner duct passes. A hub-tip ratio of the outer fan is from 1.6 to 2.2 times a hub-tip ratio of the inner fan.

An axial flow turbomachine (102) for producing thrust to propel an aircraft is shown. The turbomachine has an inner duct (202) and an outer duct (204), both of which are annular and concentric with one another. An inner fan (206) is located in the inner duct, and is configured to produce a primary pressurised flow (P). An outer fan (207) is located in an outer duct, and is configured to produce a secondary pressurised flow (S). The outer fan has a hollow hub (208) through which the inner duct passes. A hub-tip ratio of the outer fan is from 1.6 to 2.2 times a hub-tip ratio of the inner fan.

An aircraft includes a fuselage having a front, a center, and a rear section. A first mounting member is coupled to the front section. A second mounting member is coupled to the rear section. A first and a second wing are coupled to the center section. A plurality of power generator systems are included and coupled to the first or second mounting member. Each power generator system includes a power source, a first and a second propeller. The power source is configured to drive the first and second propeller. The first and second propeller have an axis of rotation, and are pivotable between a first and a second position. An amphibious landing gear system is coupled to an underside of the fuselage and has a flap and a bladder. The bladder is located under the flap, configured to inflate and deflate, and sized to provide buoyancy for the aircraft.

An aircraft includes a fuselage having a front, a center, and a rear section. A first mounting member is coupled to the front section. A second mounting member is coupled to the rear section. A first and a second wing are coupled to the center section. A plurality of power generator systems are included and coupled to the first or second mounting member. Each power generator system includes a power source, a first and a second propeller. The power source is configured to drive the first and second propeller. The first and second propeller have an axis of rotation, and are pivotable between a first and a second position. An amphibious landing gear system is coupled to an underside of the fuselage and has a flap and a bladder. The bladder is located under the flap, configured to inflate and deflate, and sized to provide buoyancy for the aircraft.

An ultra-efficient “green” aircraft propulsor utilizing an augmentor fan is disclosed. A balanced design is provided combining a fuel efficient and low-noise high bypass ratio augmentor fan and a low-noise shrouded high bypass ratio turbofan. Three mass flow streams are utilized to reduce propulsor specific fuel consumption and increase performance relative to conventional turbofans. Methods are provided for optimization of fuel efficiency, power, and noise by varying mass flow ratios of the three mass flow streams. Methods are also provided for integration of external propellers into turbofan machinery.

An ultra-efficient “green” aircraft propulsor utilizing an augmentor fan is disclosed. A balanced design is provided combining a fuel efficient and low-noise high bypass ratio augmentor fan and a low-noise shrouded high bypass ratio turbofan. Three mass flow streams are utilized to reduce propulsor specific fuel consumption and increase performance relative to conventional turbofans. Methods are provided for optimization of fuel efficiency, power, and noise by varying mass flow ratios of the three mass flow streams. Methods are also provided for integration of external propellers into turbofan machinery.