Positionable ejector member for ejector enhanced boundary layer alleviation

Patent metadata

Field	Value
Publication number	US-2016009377-A1
Application number	US-201414180032-A
Country	US
Kind code	A1
Filing date	Feb 13, 2014
Priority date	Feb 22, 2013
Publication date	Jan 14, 2016
Grant date	—

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 useful to discharge a relatively high velocity fluid stream to provide a force useful in affecting a movement of the aircraft, the fluid stream being useful 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; an airflow member structured to be moveable relative to the flow surface between a relatively open position and a relatively closed position, the airflow member capable of producing a gap between a portion of the airflow member 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 structured to operate upon a determined condition and actuate the airflow member to a variety of positions as a function of the determined condition to control the ejector, the variety of positions corresponding to respective gap distances appropriate to entrain the at least a portion of the boundary layer.

2 . The apparatus of claim 1 , wherein the flow surface comprises a nacelle of the power plant.

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

4 . The apparatus of claim 3 , wherein the airflow member comprises an ejector shroud, wherein the relatively closed position is a closed position, and wherein the controller is a digital controller.

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

6 . The apparatus of claim 5 , wherein the controller is a plurality of controllers associated with each respective power plant.

7 . The apparatus of claim 1 , wherein the determined condition includes one of a determined engine condition, flight condition, aircraft mode, and aircraft configuration and wherein, the airflow member is capable of dwelling at a plurality of positions until the determined flight condition changes.

8 . 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 a control module configured to command the ejector flow member to any of the plurality of positions 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.

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

10 . The apparatus of claim 9 , wherein the ejector flow member is an ejector shroud disposed at least partially around a nacelle of the gas turbine engine.

11 . The apparatus of claim 9 , wherein the control module is configured to command an actuator useful to change a position of the ejector flow member.

12 . The apparatus of claim 8 , wherein the ejector flow member is operable to entrain an entirety of the boundary layer.

13 . The apparatus of claim 8 , wherein the control module is structured to modulate the ejector flow member as a function of one of engine condition and flight condition.

14 . The apparatus of claim 13 , wherein the ejector flow member is an ejector shroud and wherein the control module updates a command of the ejector flow member.

15 . The apparatus of claim 8 , further comprising an aircraft and a sensor for determining an operating condition; and means for entraining the boundary layer with the working fluid as a function of the operating condition.

16 . A method comprising:
operating a gas turbine engine to produce a relatively high velocity flow stream; propelling a vehicle having the gas turbine engine to produce an external flow stream along a flow surface, the movement of the vehicle producing a boundary layer; determining a condition useful to operate an ejector forming member; and adjusting an ejector flow passage area based upon the determining between a minimum area position and a maximum area position, a position of the ejector forming member resolved from possible positions ranging between the minimum area position and maximum area position.

17 . The method of claim 16 , wherein the adjusting includes moving an ejector flow passage member to a first position and which further includes moving the ejector flow passage member to a second position based upon re-determining the condition.

18 . The method of claim 17 , wherein the adjusting includes issuing a command to an actuation member.

19 . The method of claim 18 , wherein the e-determining occurs repeatedly throughout at least a portion of a flight.

20 . The method of claim 17 , wherein the determining includes caiculating a flight condition based upon a sensed condition.

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

• B64C21/08 Primary

  adjustable · CPC title

• B64D29/00

  Power-plant nacelles, fairings or cowlings · CPC title

• Y02T50/10

  Drag reduction · CPC title

• B64C21/04

  for blowing · CPC title