High frequency jet nozzle actuators for jet noise reduction
IPC분류정보
국가/구분
United States(US) Patent
등록
국제특허분류(IPC7판)
A61F-011/06
A61F-011/00
출원번호
US-0172755
(2002-06-14)
발명자
/ 주소
Butler,George W.
Reed,David H.
Calkins,Frederick T.
Davis,Christopher L.
Mabe,James H.
출원인 / 주소
The Boeing Company
대리인 / 주소
Harness, Dickey &
인용정보
피인용 횟수 :
8인용 특허 :
9
초록▼
A noise reduction system for use with an exhaust nozzle associated with a jet engine of an aircraft. The noise reduction system employs a plurality of flow-altering components disposed circumferentially about a lip portion of an exhaust nozzle. In one preferred form the flow-altering components each
A noise reduction system for use with an exhaust nozzle associated with a jet engine of an aircraft. The noise reduction system employs a plurality of flow-altering components disposed circumferentially about a lip portion of an exhaust nozzle. In one preferred form the flow-altering components each comprise piezoelectric transduction layers. The flow-altering components are caused to move in an oscillating manner by an AC signal applied thereto such that they move into and out of the exhaust gas emitted from the exhaust nozzle to achieve a desired degree of intermixing of the exhaust flow with the flow adjacent the exhaust nozzle. This produces a reduction in the noise generated by the jet engine. The noise reduction can be utilized during takeoff conditions of an aircraft. The flow-altering components are maintained out of the exhaust gas flowpath during cruise conditions of the aircraft so as not to cause a reduction of thrust, that would in turn result in an increase in the fuel burn during cruise conditions.
대표청구항▼
What is claimed is: 1. A noise reduction system for a jet engine housed within a nacelle of an aircraft, comprising: a plurality of flow-altering components disposed circumferentially about a lip portion of an exhaust nozzle of said nacelle so as to extend adjacent to an exhaust flow emitted from s
What is claimed is: 1. A noise reduction system for a jet engine housed within a nacelle of an aircraft, comprising: a plurality of flow-altering components disposed circumferentially about a lip portion of an exhaust nozzle of said nacelle so as to extend adjacent to an exhaust flow emitted from said exhaust nozzle; each of said flow-altering components including a transduction element adapted to deform in response to an application of an electric current thereto such that each said flow-altering component extends into said exhaust flow, thereby promoting mixing of said exhaust flow with an adjacent flow stream outside of said exhaust nozzle; and a current source for controllably applying an electric current to said transduction element. 2. The system of claim 1, wherein each said flow-altering component comprises: a pair of said transduction elements; and a layer of metal disposed in between said pair of transduction elements. 3. The system of claim 2, wherein a first one of said pair of transduction elements expands when said electric current is applied thereto, and wherein a second one of said transduction elements contracts when said electric current is applied thereto, thereby causing said flow-altering component to deform and project into said exhaust flow. 4. The system of claim 1, wherein said current source comprises an alternating current source that causes said flow-altering components to move in an oscillating manner generally in accordance with a frequency and phase of said electric current output by said alternating current source. 5. The system of claim 1, wherein said flow-altering components are spaced apart generally evenly about a circumference of said lip portion of said exhaust nozzle. 6. The system of claim 1, wherein said transduction element comprises a layer of piezoelectric material. 7. A noise reduction system for a jet engine housed within a nacelle of an aircraft, comprising: a plurality of flow-altering components disposed circumferentially about a trailing lip portion of an exhaust nozzle of said nacelle so as to form extensions of said lip portion that extend adjacent to an exhaust flow emitted from said exhaust nozzle; each of said flow-altering components including: at least one transduction element adapted to deform sufficiently in response to an application of an electric current thereto such that each said flow-altering component extends, in a first position, into said exhaust flow, thereby promoting mixing of said exhaust flow with an adjacent flow stream outside of said exhaust nozzle, and in a second position generally co-planar with said lip portion so as not to extend into said exhaust flow; and a substrate secured to said transduction element for providing support to said transduction element; and a current source for controllably applying an electric current to said transduction element. 8. The system of claim 7, wherein said substrate comprises a layer of metal. 9. The system of claim 7, wherein each said flow-altering component comprises: a pair of said transduction elements; and wherein said substrate comprises a metal layer interposed between said transduction elements. 10. The system of claim 7, wherein said current source comprises an alternating current source, and wherein said alternating current generated from said alternating current source causes an oscillating movement of said flow-altering components towards and away from said exhaust flow. 11. The system of claim 10, wherein said flow-altering components oscillate at a frequency generally in accordance with a frequency and phase of said alternating current. 12. The system of claim 7, wherein each said transduction element comprises a piezoelectric layer of material. 13. The system of claim 7, wherein each of said flow altering components form rectangular-like projections extending from said trailing lip portion of said exhaust nozzle. 14. A method for reducing noise emitted from an exhaust nozzle of a jet engine, comprising: disposing a plurality of flow-altering components circumferentially about a lip portion of exhaust nozzle to extend from said lip portion, wherein each of said flow-altering components deforms in response to an electric current applied thereto so as to project, in a first position, into an exhaust flow emitted from said exhaust nozzle and in a second position to extend generally co-planar with said lip portion; and applying an electric current to said flow-altering components to thereby cause said flow-altering components to deform move from said second position into said first position, to thus project into said exhaust flow, thereby promoting mixing of said exhaust flow with an adjacent air stream outside of said exhaust nozzle to attenuate noise emitted from said exhaust nozzle. 15. The method of claim 14, wherein said step of applying electric current comprises applying an alternating current to cause said flow-altering components to oscillate towards and away from said exhaust flow. 16. The method of claim 14, wherein the step of disposing a plurality of flow-altering components comprises disposing a plurality of piezoelectric, flow-altering components circumferentially about said lip portion. 17. The method of claim 14, wherein disposing said flow altering components comprise disposing a plurality of rectangular-like flow altering components to extend from said lip portion.
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이 특허에 인용된 특허 (9)
Wanke Ronald L. (1960 N. Lincoln Park West Chicago IL 60614), Acoustic abatement method and apparatus.
Burdisso Ricardo (Blacksburg VA) Fuller Chris R. (Blacksburg VA) O\Brien Walter F. (Blacksburg VA) Thomas Russell H. (Blacksburg VA) Dungan Mary E. (Malden SC), Active control of aircraft engine inlet noise using compact sound sources and distributed error sensors.
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