Active Aircraft Pylon Noise Control System

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(12) United States Patent (io) Patent No.:

US 9,669,921 B2

(45) Date of Patent: Jun.

Thomas et al. 6,2017

(54) ACTIVE AIRCRAFT PYLON NOISE (58) Field of Classification Search CPC ....... B64C 21/04; B64C 2220/00; B64C 7/02; CONTROL SYSTEM B64C 21/02; B64D 27/18; B64D 33/06; (71) Applicant: The United States of America as B64D 27/26 represented by the Administrator of See application file for complete search history.

the National Aeronautics and Space (56) References Cited Administration, Washington, DC(US) U.S. PATENT DOCUMENTS (72) Inventors: Russell H. Thomas, Yorktown, VA (US); Michael J. Czech, Issaquah, WA 4,917,336 A * 4/1990 Jacobs et al. ................. 244/207 (US); Alaa A. Elmiligui, Virginia 6,820,410 132 11/2004 Lair Beach, VA (US) (Continued) (73) Assignee: THE UNITED STATES OF FOREIGN PATENT DOCUMENTS AMERICA AS REPRESENTED BY THE ADMINISTRATOR OF THE WO 2009107646 Al 9/2009 WO WO 2011104488 A9 * 12/2011 NATIONAL AERONAUTICS AND SPACE ADMINISTRATION, Washington, DC (US) OTHER PUBLICATIONS Steven J. Massey, Alaa A. Elmiligm, Craig A. Hunter, Russell H.

(*) Notice: Subject to any disclaimer, the term ofthis Thomas, S. Paul Pao, and Vinod G. Mengle, "Computational patent is extended or adjusted under 35 Analysis of a Chevron Nozzle Uniquely Tailored for Propulsion U.S.C. 154(b) by 0 days.

Airframe Aeroacoustics," 12th AIAA/CEAS Aeroacuoustics (21) Appl. No.: 14/703,288 Conferenence (27th AIAA Aeroacoustics Conference) May 8-10, 2006, Cambridge, Massachusetts.

(22) Filed: May 4, 2015 (Continued) (65) Prior Publication Data Primary Examiner Valentina Xavier (74) Attorney, Agent, or Firm Robin W. Edwards US 2015/0232170 Al Aug. 20, 2015 Related U.S. Application Data (57) ABSTRACT (62) Division of application No. 13/214,481, filed on Aug. An active pylon noise control system for an aircraft includes 22, 2011, now Pat. No. 9,022,311. a pylon structure connecting an engine system with an airframe surface of the aircraft and having at least one (Continued) aperture to supply a gas or fluid therethrough, an intake portion attached to the pylon structure to intake a gas or (51) Int. Cl.

fluid, a regulator connected with the intake portion via a B64C 7/02 (2006.01) plurality of pipes, to regulate a pressure of the gas or fluid, B64D 27/26 (2006.01) a plenum chamber formed within the pylon structure and B64C 21/04 (2006.01) connected with the regulator, and configured to receive the (52) U.S. Cl.

gas or fluid as regulated by the regulator, and a plurality of CPC ................ B64C 7/02 (2013.01); B64C 21/04 injectors in communication with the plenum chamber to (2013.01); B64D 27/26 (2013.01); B64C 2220100 (2013.01) (Continued) 300- - B- - ■aeaee• 350 f

US 9,669,921 B2

Page 2 actively inject the gas or fluid through the plurality of apertures of the pylon structure.

4 Claims, 6 Drawing Sheets Related U.S. Application Data (60) Provisional application No. 61/375,382,filed on Aug.

20, 2010.

(56) References Cited U.S. PATENT DOCUMENTS 2008/0272228 Al 11/2008 Mengle et al.

2010/0257865 Al 10/2010 Mengle 2011/0000181 Al * 1/2011 Oishi ........................ B64C 7/02 60/39.5 2011/0155862 Al 6/2011 Mengle OTHER PUBLICATIONS Craig A. Hunter, Russell H. Thomas, K.S. Abdol-Hamid, S. Paul Pao, Alaa A. Elmiligui, and Steven J. Massey, "Computational Analysis ofthe Flow and Acoustic Effects of Jet-Pylon Interaction," 11th AIAA/CEAS Aeroacoustics Conference May 23-25, 2005, Monterey, California.

* cited by examiner

Jun. Sheet 1 of 6 U.S. Patent 6,2017 US 9,669,921 B2 100---, 103--/ FIG. 1 (Prior Art)

Jun. Sheet 2 of 6 B2 U.S. Patent 6,2017 US 9,669,921 I ,) FIG. 2 (Prior Art)

Jun. Sheet 3 of 6

U.S. Patent 6,2017 US 9,669,921 B2

M Cd iz M

Jun. Sheet 4 of 6 B2 U.S. Patent 6,2017 US 9,669,921 405- Intake Regulator Portion 406--\ Plenum Chamber Switch 40$ti Injector Injector F - C 365--~ FIG. 4

Jun. Sheet 5 of 6 U.S. Patent 6,2017 US 9,669,921 B2 FIG. 5

Patent Jun. Sheet of 9,669,921 B2 U.S. 6, 2017 6 6 US Inputting a gas or fluid in the pylon structure Controlling a pressure of a flow of the gas or fluid input Selectively injecting the gas or fluid through at least one aperture formed on the pylon structure FIG. 6

US 9,669,921 B2

ACTIVE AIRCRAFT PYLON NOISE different operations (e.g., takeoff, approach, and cruise) of CONTROL SYSTEM the aircraft 100. The level of noise may vary depending on the operation. For example, jet noise is typically higher CROSS-REFERENCE TO RELATED during a takeoff operation. Further, shock cell noise may APPLICATIONS 5 occur during a cruising operation of the aircraft 100 which may affect the passengers and crew aboard the aircraft 100.

This patent application claims the benefit of priority to In addition, the interaction of the engine jet exhaust with a and is a divisional of U.S. patent application Ser. No.

deployed high-lift device(e.g.,flaps 105 and 119, or ailerons 13/214,481,filed Aug. 22, 2011, which claims the benefit of 113 and 117) is another source of noise and is accentuated priority under 35 U.S.C. §119 to U.S. Provisional Patent based upon a configuration of the propulsion engine system Application No. 61/375,382, with a filing date of Aug. 20, 103.

2010, the contents of the foregoing applications hereby Therefore, it is desirable to have an aircraft pylon noise incorporated by reference in their entirety.

control system capable ofreducing jet-flap interaction noise 15 and redistributing noise sources within the aircraft to ORIGIN OF THE INVENTION enhance acoustic shielding by the aircraft.

The present invention was made in part by an employee SUMMARY OF THE INVENTION of the United States Government and may be manufactured and used by or for the Government of the United States of 20 According to an embodiment of the present invention, an America for governmental purposes without the payment of active pylon noise system is provided. An active pylon noise any royalties thereon or therefore.

control system for an aircraft includes a pylon structure connecting an engine system with an airframe surface ofthe BACKGROUND OF THE INVENTION aircraft and having at least one aperture to supply a gas or The present invention relates to an aircraft pylon noise 25 fluid therethrough, an intake portion attached to the pylon control system, and more specifically, to an active aircraft structure to intake a gas or fluid, a regulator connected with pylon noise control system capable of reducing the overall the intake portion via a plurality of pipes, to regulate a noise ofan aircraft by reducing noise associated withjet-flap pressure ofthe gas or fluid, a plenum chamber formed within interaction where the engine exhaust flow interacts with a the pylon structure and connected with the regulator, and trailing edge device (e.g., flaps or ailerons) or by redistrib- 30 configured to receive the gas or fluid as regulated by the uting noise sources and reducing jet source noise or by regulator, and a plurality ofinjectors in communication with enhancing acoustic shielding of jet noise by an airframe the plenum chamber to actively inject the gas or fluid surface of the aircraft.

through the plurality of apertures of the pylon structure.

FIGS. 1 and 2 illustrate a conventional aircraft and an According to other embodiments ofthe present invention, aircraft wing of the aircraft, respectively. As shown in FIG.

35 an aircraft system includes the above-mentioned active 1, the aircraft 100 includes a fuselage 101, wings 102, and pylon noise control system and a method for the same is also a propulsion engine system 103. The propulsion engine provided.

system 103 includes engines 106 at a lower surface of the Additional features and advantages are realized through wings 102. Each engine 106 is housed in a nacelle 104 the techniques of the present invention. Other embodiments having an inlet 105 and a nozzle system 150 attached to the 40 and aspects of the invention are described in detail herein wing 102 via a pylon structure 108. FIG. 2 shows high-lift and are considered a part of the claimed invention. For a devices included on the wing 102. The high lift devices may better understanding of the invention with the advantages include deployable slats 111 positioned toward a leading and the features, refer to the description and to the drawings.

edge of the wing 102 and multiple trailing edge devices positioned toward a trailing edge of the wing 102. The 45 BRIEF DESCRIPTION OF THE DRAWINGS trailing edge devices include an outboard aileron 113, an outboard flap 105, an inboard aileron 117, and an inboard The subject matter, which is regarded as the invention, is flap 119. The outboard and inboard ailerons 113 and 117 are particularly pointed out and distinctly claimed in the claims typically used for roll control of the aircraft 100 while the at the conclusion ofthe specification. The forgoing and other outboard and inboard flaps 105 and 119 are used to control 50 features, and advantages of the invention are apparent from the lift of the aircraft 100 during takeoff and landing the following detailed description taken in conjunction with operations. The ailerons 113 and 117 are hinged devices that the accompanying drawings in which: are un-gapped when in their deployed position. When the FIG. 1 illustrates a conventional aircraft.

flaps 105 and 119 are deployed, they rotate and move in an FIG. 2 illustrates a wing of the conventional aircraft aft direction to open a gap relative to the wing 102 (as 55 shown in FIG. 1.

depicted by arrows 121 and 123). Since the motion path of FIG. 3 is a partial schematic of a propulsion engine the inboard flap 119 (as indicated by arrow 121) converges system that can be implemented within embodiments of the with the motion path of the outboard flap 105, the inboard present invention.

aileron 117 located between the flaps 105 and 119 may be a FIG. 4 is a diagram illustrating an active pylon noise hinged device and does not move aft when deployed (as 60 control system that can be implemented within embodiments indicated by arrow 125). When a flaperon is used in place of of the present invention.

the inboard aileron 117, it moves in an aft direction unlike FIG. 5 is a schematic illustrating a heat shield formed on the inboard aileron 117. a pylon structure that can be implemented within other Aircraft noise continues to have a significant negative embodiments of the present invention.

impact on the environment, e.g., on the air transportation 65 FIG. 6 is a flowchart illustrating a method for injecting a system and the public, There are several factors that con- gas or fluid into a pylon structure of an aircraft that can be tribute to overall aircraft noise. These factors include the implemented within embodiments of the present invention.

US 9,669,921 B2

3 4

DETAILED DESCRIPTION OF THE passively based on a higher pressure of gas or fluid from the INVENTION intake flowing through the pipes 405 and where the pump may create an even higher pressure and also may control the The present invention describes an active pylon noise pressure through the noise control system 400.

control system that can be implemented within existing 5 A plenum chamber 406 is also formed within the pylon pylon structures or new pylon structures of an aircraft. The structure 360 and is connected with the regulator and/or active pylon noise control system of the present invention pump 404, and configured to receive the gas or fluid as provides a method for actively injecting gas or fluid such as regulated by the regulator and/or pump 404. The plenum air through a pylon structure ofthe aircraft Details regarding chamber 406 is connected with and communicates with a the active pylon noise control system and the method will be io plurality ofinjectors 408 configured to actively inject the gas discussed below with reference to FIGS. 3 through 6.

or fluid through the apertures 365. The plenum chamber 406 FIG. 3 is a partial schematic of a propulsion engine distributes the gas or fluid so that it can be delivered to the system that can be implemented within embodiments of the injectors 408 in a uniform flow profile and pressure. The gas present invention. As shown in FIG. 3, a portion 300 of an or fluid is then release from the injectors (Arrow Q.

aircraft is provided. Awing 302 includes a propulsion engine 15 According to an embodiment of the present invention, a system 303 attached thereto. The engine system 303 switch 410 is provided and attached to the plurality of includes an engine (not shown) housed in a nacelle 304, and injectors 408 to selectively direct the gas or fluid to at least a nozzle system 350 for releasing exhaust flow from the one of the injectors 408.

engine. The nozzle system 350 includes a fan nozzle 351 According to an embodiment of the present invention, the configured to receive a fan flow from a fan (not shown) 20 disposed adjacent to an engine disposed above an airframe aperture 365 is formed within a shelf surface or a trailing surface (e.g., the wing 302) of the aircraft and a core nozzle edge surface of the pylon structure 360. The gas or fluid is 352 disposed within the fan nozzle 351 and configured to therefore injected through the shelf surface or the trailing receive an engine core flow. The nozzle system 350 further edge surface as indicated by the arrows A and B shown in includes a plug 355 formed within the core nozzle 352. 25 FIG. 3. An injection angle of the gas or fluid injected from According to an embodiment of the present invention, a the injectors 408 may be angled perpendicular to the exhaust pylon structure 360 is connected to the fan nozzle 351 and flow direction or angled in a downstream direction or at an structurally attached with the wing 302 to secure the engine angle therebetween (Arrows B) if injected from the shelf system 303 to the aircraft. In this embodiment of the present surface or a heat shield of the pylon structure 360, or a invention, the engine system 303 is attached to a lower 30 trailing edge direction (i.e., a downstream direction)(Arrow surface ofthe wing 302, however the present invention is not A) if injected from the trailing edge surface of the pylon limited hereto and the engine system 303 may be attached to structure 360. The injection of the gas or fluid alters a an upper surface of the wing, the tail, the fuselage or to an trajectory of a flow of the core nozzle 352 and a flow of the upper surface of a hybrid body-wing configuration of an fan nozzle 351, and impacts a mixing process of the flow of aircraft. The pylon noise control system of the present 35 the core nozzle 352 and the flow of the fan nozzle 351. At invention supplies a gas or fluid through the pylon structure cruise conditions, the invention can be used by adjusting the 360 of the aircraft. According to an embodiment of the regulator and/or pump to inject very small levels of flow present invention, the fluid may be air or a gas mixture, from the shelf, microblowing, in order to reduce drag water or other liquid. Details regarding the active pylon associated with high-speed core flow scrubbing over the noise control system will now be discussed below with 40 shelf surface.

reference to FIGS. 3 through 5. According to an embodiment of the present invention, FIG. 4 is a diagram illustrating an active pylon noise when an injector 408 is formed at the trailing edge surface control system that can be implemented within embodiments of the pylon structure 360, the wake of the pylon structure of the present invention. 360 is affected by injecting a higher pressure and velocity of As shown in FIG. 4, the active pylon noise control system 45 air through the respective injector 408 (arrow A depicted in 400 includes the pylon structure 360 which comprises at FIG. 3). Further, since the mixing of the flow of the core least one aperture 365 (i.e., a slot or a plurality of apertures) nozzle 352 and ofthe fan nozzle 351 is changed,the strength to supply a gas or fluid therethrough. The noise control and distribution of the aircraft noise sources is altered. The system 400 further includes an intake portion 402 attached strengths of the aircraft noise sources are reduced and move to the pylon structure 360 and configured to intake a gas or 50 upstream instead of downstream. Further, the overall trajec- fluid. According to an embodiment of the present invention, tory of the aircraft is altered away from the high-lift devices the intake portion 402 may be formed on at least one (i.e., the flaps or ailerons) included on the wing 302. The junction between the nacelle 304 and the pylon structure present invention is not limited to the apertures 365 being 360, on the side, upper surface or leading edge of the pylon formed on a shelf surface or trailing edge surface of the structure 360, on the side or leading edge of the pylon 55 pylon structure 360. According to an embodiment of the structure that is interior (e.g., an upper bifurcator, not present invention, the apertures 365 may be formed on a heat shown) to the nacelle 304, or on an inner surface of the shield of the pylon structure. A detailed description will be nacelle 304. The intake offluid from these surfaces can also discussed below with reference to FIG. 5 result in drag reduction, an additional desirable aspect of the FIG. 5 is a schematic illustrating a heat shield formed on present invention. 60 the shelf of a pylon structure that can be implemented within The noise control system 400 further includes a regulator other embodiments of the present invention. According to and/or pump 404 connected with the intake portion 402 via another embodiment of the present invention, the pylon a pipe(s) 405, and is configured to regulate a pressure of the structure 360 includes a heat shield 362. As shown in FIG.

gas or fluid received from the intake portion 402. According 5, an inner surface of the heat shield facing the core nozzle to other embodiments of the present invention, a regulator 65 352 includes a perforated surface that includes a plurality of and/or a pump is provided to control the pressure of the gas apertures 365. The gas or fluid is therefore injected through or fluid. Thus, the noise control system 400 may operate the perforated surface.

US 9,669,921 B2

5 6

FIG. 6 is a flowchart illustrating a method for injecting a the present invention has been presented for purposes of gas or fluid into a pylon structure of an aircraft that can be illustration and description, but is not intended to be exhaus- implemented within embodiments of the present invention. tive or limited to the invention in the form disclosed. Many As shown in FIG. 6, at operation 600, a gas or fluid is modifications and variations will be apparent to those of input into the pylon structure 360 via the intake portion 402. 5 ordinary skill in the art without departing from the scope and From operation 600, the process continues to operation 610, spirit of the invention. The embodiment was chosen and where a pressure of the flow of the gas or fluid input in the described in order to best explain the principles of the pylon structure 360 is controlled via the regulator and/or invention and the practical application, and to enable others pump 404. The gas or fluid is selectively injected, at of ordinary skill in the art to understand the invention for operation 615, through at least one aperture 365 formed on io various embodiments with various modifications as are the pylon structure 360, via the switch 410. This selection suited to the particular use contemplated. It is therefore to be may involve injecting the gas or fluid through the shelf understood that, within the scope of the appended claims, surface or the trailing edge surface of the pylon structure the invention may be practiced other than as specifically 360. described.

Embodiments of the present invention provide an active 15 What is claimed as new and desired to be secured by pylon noise control system that is capable of reducing Letters Patent of the United States is: overall aircraft noise by injecting air, for example, through 1. A method for injecting a gas or fluid from a pylon a pylon structure attaching the engine system to the airframe structure of an aircraft into an exhaust flow from a nozzle of surface of the aircraft. In this system, the flow rate of the air 20 an engine, the method comprising: is adjustable at different operating points of the aircraft, and inputting a gas or fluid in the pylon structure; the system operates at relatively low pressures, typically less controlling a pressure of a flow of the gas or fluid input in than approximately two atmospheres of pressure. The sys- the pylon structure; and tem is applicable to different aircraft configurations and may selectively injecting the gas or fluid through at least one be implemented within existing pylon structures.

25 aperture formed on the pylon structure aft ofthe nozzle The terminology used herein is for the purpose of describ- of the engine.

ing particular embodiments only and is not intended to be 2. The method of claim 1, wherein selectively injecting limiting of the invention. As used herein, the singular forms the gas or fluid comprises selectively directing the gas or "a,""an," and "the" are intended to include the plural forms fluid to at least one injector.

as well, unless the context clearly indicates otherwise. It will 3. The method of claim 2, wherein selectively injecting be further understood that the terms "comprises" and/or 30 the gas or fluid further comprises selecting injecting the gas "comprising," when used in this specification, specify the or fluid through the at least one aperture formed at a shelf presence of stated features, integers, steps, operations, ele- surface or a trailing edge surface of the pylon structure.

ments, and/or components, but do not preclude the presence 4. The method of claim 3, wherein an injection angle of or addition of one ore more other features, integers, steps, 35 the gas or fluid is an angle perpendicular to an exhaust flow operations, element components, and/or groups thereof.

direction or in a downstream direction or an angle therebe- The corresponding structures, materials, acts, and equiva- tween ifinjected from the shelf surface or a heat shield ofthe lents of all means or step plus function elements in the pylon structure, or in a downstream direction if injected claims below are intended to include any structure, material, from the trailing edge surface of the pylon structure.

or act for performing the function in combination with other claimed elements as specifically claimed. The description of