Positionable ejector member for ejector enhanced boundary layer alleviation

Patent metadata

Field	Value
Publication number	US-9630706-B2
Application number	US-201414180032-A
Country	US
Kind code	B2
Filing date	Feb 13, 2014
Priority date	Feb 22, 2013
Publication date	Apr 25, 2017
Grant date	Apr 25, 2017

Abstract

An aircraft having a moveable ejector member for assisting in alleviating a boundary layer flowing along an aircraft surface is disclosed. The moveable ejector member is capable of being placed at a variety of positions between a fully open position and a nested position to entrain the boundary layer with another fluid flow. The ejector member can take the form of an ejector shroud used with a nacelle. In some forms, a gas turbine engine is used to provide an ejector flow to entrain the boundary layer through the flow path.

First claim

What is claimed is:

1. An apparatus comprising:
an aircraft having a power plant configured to discharge a fluid stream to provide a force that affects a movement of the aircraft, the fluid stream adapted for use as a primary flow stream of an ejector;
a flow surface over which a working fluid passes to form a boundary layer as the aircraft is in motion, the flow surface comprising a nacelle of the power plant;
an ejector having an ejector shroud structured to be moveable fore and aft relative to the flow surface between an open position and a closed position, the ejector shroud capable of producing a gap between a portion of the ejector shroud and the flow surface, wherein the gap serves to capture at least a portion of the boundary layer from the flow surface and provide it as a secondary flow stream of the ejector; and
a controller configured to operate upon a determined condition and actuate the ejector shroud to a variety of positions between the open position and the closed position as a function of the determined condition to control the ejector, and the determined condition includes one of a determined aircraft altitude, static temperature, static pressure, total temperature, total pressure, and aircraft configuration.

2. The apparatus of claim 1 , wherein the power plant is a gas turbine engine and the fluid stream is an exhaust of the gas turbine engine.

3. The apparatus of claim 2 , wherein the aircraft includes a plurality of power plants each having respective ejector shrouds and wherein the respective ejector shroud can be commanded to a series of discrete positions as result of the controller operating upon a series of determined conditions.

4. The apparatus of claim 3 , wherein the controller is a plurality of controllers associated with each respective power plant.

5. The apparatus of claim 1 , wherein the ejector shroud is configured to rotate to cause the ejector shroud to move fore and aft with respect to an axial direction of the power plant.

6. The apparatus of claim 1 , further including a mechanical ratchet system configured to move the ejector shroud in pre-set steps between the open position and the closed position.

7. An apparatus comprising:
a gas turbine engine that includes a compressor, combustor, and turbine and a passage for flowing a working fluid produced during operation of the gas turbine engine;
an aircraft flow surface structured to form a boundary for the passage of a gas, a boundary layer formed as the gas is passed along the aircraft flow surface;
an ejector flow member in proximity to the aircraft flow surface and capable of being actuated to a plurality of positions to vary an ejector passage formed between the ejector flow member and the aircraft flow surface, the ejector passage oriented to capture the boundary layer formed on the aircraft flow surface, and the ejector flow member includes a rotatable ejector shroud; and
a control module including sensors, an actuator, and a controller, the sensors configured to asses a plurality of flight conditions of the gas turbine engine and determine a position of the ejector flow member relative to the aircraft flow surface, the actuator configured to rotate the rotatable ejector shroud to cause the ejector flow member to move axially forward and aft with respect to an axial direction of the gas turbine engine, and the controller configured to command the actuator to move the ejector flow member to any of the plurality of positions, based on outputs received from the sensor and the determined position of the ejector flow member relative to the aircraft flow surface, to entrain a momentum thickness of the boundary layer with the working fluid produced during operation of the gas turbine engine that is flowed through the passage.

8. The apparatus of claim 7 , wherein the passage is an exhaust and the working fluid is an exhaust gas, and which further includes an aircraft.

9. The apparatus of claim 7 , wherein the ejector flow member is operable to entrain an entirety of the boundary layer.

10. The apparatus of claim 7 , wherein the control module is structured to modulate the ejector flow member as a function of one of engine condition and flight condition.

11. The apparatus of claim 7 , wherein the variety of flight conditions include at least one of an aircraft altitude, shaft speed, static temperature, static pressure, total temperature, and total pressure.

12. The apparatus of claim 7 , wherein the sensors include boundary layer rakes that extend into the working fluid.

Assignees

• Rolls Royce Corp

Inventors

• Khalid Syed J

Classifications

• B64C2230/06

  by explicitly adjusting fluid flow, e.g. by using valves, variable aperture or slot areas, variable pump action or variable fluid pressure · CPC title

• Y02T50/166

  Cross-Sectional Technologies · mapped topic

• B64C21/04

  for blowing · CPC title

• B64C21/08 Primary

  adjustable · CPC title

• Y02T50/10

  Drag reduction · CPC title