Fan blade with internal magnetorheological fluid damping

Patent metadata

Field	Value
Publication number	US-11560801-B1
Application number	US-202117561632-A
Country	US
Kind code	B1
Filing date	Dec 23, 2021
Priority date	Dec 23, 2021
Publication date	Jan 24, 2023
Grant date	Jan 24, 2023

Abstract

An airfoil for use in a gas turbine engine is formed to define a cavity formed in the airfoil. The airfoil further includes at least one obstructing member arranged within the cavity and a magnetorheological fluid disposed in the cavity. A viscosity of the magnetorheological fluid increases in response to a magnetic field being generated proximate to the fluid in response to the airfoil experiencing an aeromechanic response or vibrations. As such, the obstruction of the movement of the thicker fluid by the obstructing member dampens the vibrations of the airfoil and reduces negative effects of a dynamic response of the airfoil.

First claim

What is claimed is:

1. An airfoil assembly for use in a gas turbine engine, the airfoil assembly comprising
at least one airfoil including an airfoil body extending radially outwardly relative to an axis and configured to interact with gases surrounding the airfoil body, the airfoil body having a leading edge, a trailing edge opposite the leading edge, a pressure side, and a suction side opposite the pressure side, the airfoil body formed to define a cavity within the airfoil body, the cavity being defined by a radially outer top surface, a radially inner bottom surface, a first inner side surface, a second inner side surface, a pressure side surface, and a suction side surface the airfoil body including a magnetorheological fluid disposed within the cavity, the at least one airfoil further including at least one obstructing member arranged within the cavity and configured to obstruct movement of the magnetorheological fluid within the cavity, and
at least one electromagnet configured to generate a first magnetic field and a second magnetic field different than the first magnetic field, wherein the first magnetic field causes the magnetorheological fluid to have a first viscosity, wherein the second magnetic field causes the magnetorheological fluid to have a second viscosity, wherein the second viscosity is greater than the first viscosity, wherein the at least one electromagnet is configured to generate the second magnetic field in response to the airfoil operating in a first operating condition that causes at least one of an aeromechanical response and vibrations in the airfoil,
wherein the at least one obstructing member is configured to obstruct movement of the magnetorheological fluid within the cavity in response to the magnetorheological fluid having the second viscosity so as to dampen vibrations of the airfoil and reduce negative effects of a dynamic response of the airfoil.

2. The airfoil assembly of claim 1 , wherein the at least one obstructing member includes a plurality of pegs that each extend from the pressure side surface to the suction side surface of the cavity.

3. The airfoil assembly of claim 2 , wherein the plurality of pegs includes at least two rows of pegs, each row including at least two pegs, wherein each row of pegs of the at least two rows of pegs extends from the leading edge to the trailing edge in a direction generally perpendicular to the leading edge and the trailing edge, wherein each row of pegs of the at least two rows of pegs is spaced apart from an adjacent row of pegs in a radially direction.

4. The airfoil assembly of claim 1 , wherein the at least one obstructing member includes a plurality of radially extending walls, the plurality of radially extending walls including at least one first wall that extends radially outwardly away from the radially inner bottom surface towards the radially outer top surface of the cavity, the at least one first wall extending partway from the radially inner bottom surface towards the radially outer top surface of the cavity, the plurality of radially extending walls further including at least one second wall that extends radially inwardly away from the radially outer top surface towards the radially inner bottom surface of the cavity, the at least one second wall extending partway from the radially outer top surface towards the radially inner bottom surface of the cavity.

5. The airfoil assembly of claim 4 , wherein the at least one first wall extends generally perpendicularly away from the radially inner bottom surface of the cavity and the at least one second wall extends generally perpendicularly away from the radially outer top surface of the cavity, wherein each wall of the at least one first wall and the at least one second wall includes a terminal end, wherein the plurality of radially extending walls alternate between the at least one first wall and the at least one second wall in a direction from the leading edge to the trailing edge, and wherein each wall of the at least one first wall extends radially beyond a terminal end of an adjacent second wall of the at least one second wall.

6. The airfoil assembly of claim 1 , wherein the at least one obstructing member includes a plurality of angled walls, the plurality of angled walls including at least one first angled wall that extends away from the first inner side surface of the cavity towards the radially inner bottom surface and the second inner side surface, the at least one first angled wall extending at a first angle relative to the first inner side surface and extending partway from the first inner side surface of the cavity towards the radially inner bottom surface and the second inner side surface, the plurality of angled walls further including at least one second angled wall that extends away from the second inner side surface of the cavity towards the radially outer top surface and the first inner side surface, the at least one second angled wall extending at the first angle relative to the second inner side surface and extending partway from the second inner side surface of the cavity towards the radially outer top surface and the first inner side surface such that each first angled wall is parallel to each second angled wall.

7. The airfoil assembly of claim 6 , wherein each angled wall of the at least one first angled wall and the at least one second angled wall includes a terminal end, wherein the plurality of angled walls alternate between the at least one first angled wall and the at least one second angled wall in a direction from the radially inner bottom surface to the radially outer top surface of the cavity, and wherein each angled wall of the at least one first angled wall extends beyond a terminal end of an adjacent second angled wall of the at least one second angled wall.

8. The airfoil assembly of claim 1 , further comprising:
at least one of (i) a rotor assembly including a wheel configured to rotate about the axis and the at least one airfoil extending radially outward from the wheel, and (ii) a vane assembly including at least one inner platform, at least one outer platform, and the at least one airfoil arranged between the at least one inner platform and the at least one outer platform,
wherein the at least one electromagnet is arranged radially outward of the at least one airfoil.

9. The airfoil assembly of claim 1 , further comprising:
at least one of (i) a rotor assembly including a wheel configured to rotate about the axis and the at least one airfoil extending radially outward from the wheel, and (ii) a vane assembly including at least one inner platform, at least one outer platform, and the at least one airfoil arranged between the at least one inner platform and the at least one outer platform,
wherein the at least one electromagnet is arranged radially inward of the at least one airfoil.

10. The airfoil assembly of claim 1 , further comprising
at least one sensor configured to determine an operating condition of the airfoil, and
a controller operably connected to the at least one sensor and to the at least one electromagnet,
wherein, in response to the at least one sensor determining that the airfoil is operating in the first operating condition, the controller is configured to instruct the at least one electromagnet to generate the second magnetic field such that the magnetorheological fluid has the second viscosity, and
wherein the first operating condition includes at least one of a predetermined speed of rotation of the airfoil, a predetermined speed of forward travel of the airfoil, a predetermined vibration of the airfoil, and a predetermined distortion level of air flow interacting with the airfoil.

11. A gas turbine engine, c

Assignees

• Rolls Royce Nam Tech Inc
• Rolls Royce Corp

Inventors

• Heeter Robert W
• Molnar Jr Daniel E
• Hall Christopher D

Classifications

• F01D5/16 Primary

  for counteracting blade vibration · CPC title

• F05D2260/96

  Preventing, counteracting or reducing vibration or noise · CPC title

• F01D5/187

  Convection cooling · CPC title

• F05D2300/507

  Magnetic properties · CPC title

• F05D2260/903

  using electrical or magnetic forces · CPC title