Fan-stator interaction tone reduction
AssigneePratt & Whitney Canada Corp.
InventorMan-Chun Tse
Life of this patent
Estimating the term…
Abstract
A gas turbine engine rotor assembly such as a fan or compressor includes fan blades spaced axially from stator vanes inside an annular duct. A controlled air blowing system is secured to the annular duct and adapted to blow a hot air flow in a direction opposite to the rotation of the fan blades into the annular duct between the fan blades and the stator vanes, to impart an opposite rotational momentum with respect to the air compressed by the rotor blades, in a asymmetrical pattern to interfere with or destroy a symmetrical pattern of the blade rotation-wake of the compressed air, thereby reducing the strength or preventing the generation of the spinning mode so that the fan-stator interaction tones are significantly reduced.
Claims14
A method for reducing rotor-stator interaction tones in an annular duct surrounding a plurality of circumferentially spaced rotor blades and a plurality of circumferentially spaced stator vanes axially spaced apart from the rotor blades, the annular duct including an inlet for receiving air and an outlet for discharging at least a portion of the air compressed by the rotor blades, comprising a step of proving a controlled air blowing system for blowing an air flow in a direction opposite to the rotation of blade-wakes into the annular duct between the rotor blades and the stator vanes to impart an opposite rotational momentum with respect to the air compressed by the rotor blades, thereby reducing the strength of a spinning mode generated by a symmetrical pattern of the blade rotation-wakes of the compressed air.
A gas turbine engine fan assembly comprising:
- a plurality of circumferentially spaced rotor blades;
- a plurality of circumferentially spaced stator vanes axially spaced apart from the rotor blades;
- an annular duct surrounding the rotor blades and stator vanes, and having an inlet for receiving air and an outlet for discharging at least a portion of the air upon compression by the blades;
- and
- means for blowing an air flow in a direction opposite to the rotation of blade-wakes into the annular duct between the rotor blades and the stator vanes to impart an opposite rotational momentum with respect to the air compressed by the rotor blades, thereby reducing the strength of a spinning mode generated by a symmetrical pattern of the blade rotation-wakes of the compressed air.
Dependencies are inferred from the claim text.