Ducted fan with fan casing defining an over-rotor cavity
AssigneeGeneral Electric Company
InventorsDaniel Lawrence Tweedt, Syed Arif Khalid
Life of this patent
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Abstract
A ducted fan is provided including a fan casing surrounding a plurality of fan blades mounted to a rotating drive shaft. The plurality of blades define a tip stagger angle of greater than 68 degrees and the fan casing defines an annular recess defined by an inner wall of the fan casing, the annular recess extending about the circumferential direction proximate a blade tip of each of the plurality of blades. The annular recess may define an average recess depth greater than 10 percent of the tip chord length. The annular recess may also define a length ratio equal to a recess length over the tip axial chord length that is greater than 1.5.
Claims26
A ducted fan defining an axial direction, a radial direction, and a circumferential direction, the ducted fan comprising:
- a fan casing extending about the circumferential direction and defining a flow passageway;
- a drive shaft positioned within the fan casing and being rotatable about the axial direction;
- a plurality of blades operably coupled to the drive shaft and extending substantially along the radial direction toward the fan casing, the plurality of blades defining a tip stagger angle of greater than 68 degrees;
- and
- a permanent recess defined by an inner wall of the fan casing, the recess extending about the circumferential direction proximate a blade tip of each of the plurality of blades.
A ducted fan defining an axial direction, a radial direction, and a circumferential direction, the ducted fan comprising:
- a fan casing extending about the circumferential direction and defining a flow passageway;
- a drive shaft positioned within the fan casing and being rotatable about the axial direction;
- a plurality of blades operably coupled to the drive shaft and extending substantially along the radial direction toward the fan casing, the plurality of blades of the ducted fan with a flow coefficient, determined based on a blade tip speed, of less than 0.4;
- and
- a permanent recess defined by an inner wall of the fan casing, the recess extending about the circumferential direction proximate a blade tip of each of the plurality of blades.
A ducted fan defining an axial direction, a radial direction, and a circumferential direction, the ducted fan comprising:
- a fan casing extending about the circumferential direction and defining a flow passageway;
- a drive shaft positioned within the fan casing and being rotatable about the axial direction;
- a plurality of blades operably coupled to the drive shaft and extending substantially along the radial direction toward the fan casing;
- and
- a permanent recess defined by an inner wall of the fan casing proximate a blade tip of each of the plurality of blades, wherein the recess defines an average recess depth measured along the radial direction, the average recess depth being greater than 1.0 percent of a tip radius of the plurality of blades.
Dependencies are inferred from the claim text.