| 摘要 |
A double-ducted fan (2000) includes a hub (200), a rotor (205) having a plurality of blades (207) rotatably coupled to the hub (200), a first duct (210), a second duct (220), and a channel (230) defined between the first duct (210) and second duct (220). The first duct (210) circumscribes the rotor (205) and the second duct (220) circumscribes at least a portion of the first duct (210). The second duct (220) can be oriented axially upward such that there is an axial distance is between the leading edges (213, 245) of the first duct (210) and second duct (220). The channel (230) can be configured to direct air flow cross-wise to the first duct (210) over a leading edge (213) of the first duct (210) into the inlet (225) of the rotor (205). The second duct (220) can be movable relative to the first duct (210) to adjust at least a portion of the width (275) of the channel (230). The length (255) of the first duct (210) can be different from the length (250) of the second duct (220). |
