Active bleed for airfoils

Patent metadata

Field	Value
Publication number	US-9512821-B2
Application number	US-201313967566-A
Country	US
Kind code	B2
Filing date	Aug 15, 2013
Priority date	Aug 15, 2013
Publication date	Dec 6, 2016
Grant date	Dec 6, 2016

Abstract

An airfoil active bleed system and related method. A housing includes an induction wall, an exhaust wall having one or more exhaust ports, and a chamber between the induction and exhaust walls. Zero-net-mass-flux actuators are located in the chamber and configured and positioned to collectively induct fluid through the induction wall and selectively exhaust fluid through the exhaust port(s).

First claim

What is claimed is:

1. An airfoil active boundary layer control system, comprising:
a housing including an induction wall having a gas permeable surface, an exhaust wall having at least one exhaust port, and a chamber disposed between and at least partially defined by the induction and exhaust walls; and
at least one zero-net-mass-flux actuator in the chamber including an actuator orifice in fluid communication with the gas permeable surface of the induction wall and the at least one exhaust port, the actuator orifice being aligned with the at least one exhaust port.

2. The airfoil active boundary layer control system of claim 1 , wherein the gas permeable surface includes at least one of a porous surface or an apertured surface.

3. The airfoil active boundary layer control system of claim 1 , wherein the at least one exhaust port includes a nozzle.

4. The airfoil active boundary layer control system of claim 3 , wherein the actuator orifice axially overlaps the nozzle in a direction along an exhaust axis extending longitudinally through the nozzle.

5. The airfoil active boundary layer control system of claim 3 , wherein the nozzle is larger in diameter than the actuator orifice.

6. The airfoil active boundary layer control system of claim 3 , wherein the nozzle includes a nozzle entrance on an interior side of the exhaust wall and an exit on an exterior side of the exhaust wall.

7. The airfoil active boundary layer control system of claim 6 , wherein the nozzle entrance has a larger diameter than the nozzle exit and the actuator orifice is conically convergent at an open end and circumscribed by the nozzle entrance.

8. The airfoil active boundary layer control system of claim 1 , wherein the actuator orifice is in registration with the at least one exhaust port.

9. An airfoil including the airfoil active boundary layer control system of claim 1 , and also including:
a leading surface;
a trailing surface spaced from the leading surface;
a pressure surface extending between the leading and trailing surfaces;
a suction surface extending the leading and trailing surfaces; and
a bleed path that opens to the suction surface, extends through the airfoil, and through which working fluid flows to actively bleed working fluid from the suction surface,
wherein the airfoil active boundary layer control system of claim 1 is carried between the pressure and suction surfaces with the induction wall of the airfoil active boundary layer control system being part of the bleed path at the suction surface.

10. The airfoil of claim 9 , wherein the bleed path includes:
an inlet in the suction surface to receive working fluid on the suction surface;
a conduit in communication with the inlet and configured to convey the working fluid from the inlet toward the tip region; and
an outlet in communication with the conduit, disposed radially outwardly of the inlet to exhaust the working fluid from the conduit.

11. An active boundary layer control for an airfoil, comprising:
a housing including an induction wall having a gas permeable surface, an exhaust wall having one or more exhaust ports, and a chamber between the induction and exhaust walls;
a plurality of zero-net-mass-flux actuators located in the chamber and configured and positioned to at least augment bleed through the airfoil by collectively inducting fluid through the gas permeable surface of the induction wall and selectively exhausting fluid through the one or more exhaust ports; and
a plurality of actuator orifices carried by respective actuators of the plurality of zero-net-mass-flux-actuators, the plurality of actuator orifices being positioned and aligned to entrain into a respective one of the one or more exhaust ports at least some air that does not pass through the plurality of actuator orifices.

12. The active boundary layer control system of claim 11 , wherein the gas permeable surface includes at least one of a porous surface or an apertured surface, the one or more exhaust ports include nozzles including nozzle entrances.

13. The active boundary layer control system of claim 12 , wherein the nozzle entrances have larger diameters than the nozzle exits and actuator orifices of the plurality of actuator orifices are conically convergent at open ends and circumscribed by the nozzle entrances and actuator orifices axially overlap the nozzle entrances in a direction along exhaust axes extending longitudinally through the nozzles.

14. The active boundary layer control system of claim 11 , wherein actuator orifices of the plurality of actuator orifices are in registration with the one or more exhaust ports.

15. An airfoil including the active boundary layer control system of claim 11 , and also including:
a leading surface;
a trailing surface spaced from the leading surface;
a pressure surface extending between the leading and trailing surfaces;
a suction surface extending the leading and trailing surfaces; and
a bleed path that opens to the suction surface, extending through the airfoil, and through which working fluid flows to actively bleed working fluid from the suction surface,
wherein the active boundary layer control system of claim 11 is carried between the pressure and suction surfaces with the induction wall of the active boundary layer control system being part of the bleed path at the suction surface.

16. The active boundary layer control system of claim 11 , wherein the housing includes a plurality of exhaust walls, each having a plurality of the exhaust ports and each corresponding to multiple zero-net-mass-flux actuators.

17. The active boundary layer control system of claim 11 , wherein the plurality of zero-net-mass-flux actuators are arranged in an array evenly distributed in the housing including respective zero-net-mass-flux actuators associated with the exhaust wall having side walls, end walls, and a bottom wall.

18. A method of actively controlling a boundary layer of fluid flowing over an airfoil suction surface, comprising:
inducting at least some of the fluid through a portion of the airfoil suction surface, into a chamber under the airfoil suction surface, and into an actuator orifice of a zero-net-mass-flux actuator located in the chamber; and
exhausting fluid out of the zero-net-mass-flux actuator through the actuator orifice thereof, through a chamber exhaust port located in an exhaust wall that is aligned with the actuator orifice, and out of the chamber exhaust port to an interior of the airfoil.

Assignees

• Lockheed Corp

Inventors

• Baruzzini Dan
• Domel Neal David
• Hakes Jeffrey G
• Miller Daniel N

Classifications

• B64C21/06

  for sucking (BLI propulsion B64C21/01) · CPC title

• Y02T50/166

  Cross-Sectional Technologies · mapped topic

• Y02E10/723

  Cross-Sectional Technologies · mapped topic

• F15D1/0055

  comprising apertures in the surface, through which fluid is withdrawn from or injected into the flow · CPC title

• F05B2240/30

  Characteristics of rotor blades, i.e. of any element transforming dynamic fluid energy to or from rotational energy and being attached to a rotor · CPC title