Methods and apparatus for passive thrust vectoring and plume deflection
원문보기
IPC분류정보
국가/구분
United States(US) Patent
등록
국제특허분류(IPC7판)
F02K-001/00
F02K-001/06
F02K-001/30
F02K-001/46
B64C-007/02
B64D-033/04
출원번호
US-0496526
(2014-09-25)
등록번호
US-9732700
(2017-08-15)
발명자
/ 주소
Cerra, David F.
Willie, Robert H.
Prieto, Alvaro
출원인 / 주소
The Boeing Company
대리인 / 주소
Hanley, Flight & Zimmerman, LLC
인용정보
피인용 횟수 :
0인용 특허 :
6
초록▼
A flow vectoring turbofan engine employs a fixed geometry fan sleeve and core cowl forming a nozzle incorporating an asymmetric convergent/divergent (con-di) and/or curvature section which varies angularly from a midplane for reduced pressure in a first operating condition to induce flow turning and
A flow vectoring turbofan engine employs a fixed geometry fan sleeve and core cowl forming a nozzle incorporating an asymmetric convergent/divergent (con-di) and/or curvature section which varies angularly from a midplane for reduced pressure in a first operating condition to induce flow turning and axially symmetric equal pressure in a second operating condition for substantially axial flow.
대표청구항▼
1. A jet propulsion device having a flow vectoring duct, the jet propulsion device comprising: a substantially annular exhaust duct surrounding a jet engine center body forming a pair of concentric opposing inner and outer walls;a throat region substantially symmetrically positioned in the outer wal
1. A jet propulsion device having a flow vectoring duct, the jet propulsion device comprising: a substantially annular exhaust duct surrounding a jet engine center body forming a pair of concentric opposing inner and outer walls;a throat region substantially symmetrically positioned in the outer wall of the exhaust duct forming a region of convergence, where the inner and outer walls converge, an amount of convergence varying longitudinally along the inner and outer walls; anda region of divergence, where the inner and outer walls diverge, an amount of divergence varying longitudinally along the inner and outer walls, an exit vector of an outlet plume at a first bypass engine operating condition is different than the exit vector at a second bypass engine operating condition, wherein the exit vector of the outlet plume transitions at a nozzle pressure ratio of approximately between 1.6 and 1.89, a first transition from the first bypass engine operating condition to the second bypass engine operating condition at which the differential directing of the plume occurs corresponds to a second transition between a low speed operation and a high speed operation. 2. The jet propulsion device as defined in claim 1, wherein the exhaust duct includes a fixed geometry fan sleeve and a core cowl forming a nozzle, the nozzle incorporating asymmetric convergence/divergence (con-di) and wall curvature varying angularly from a midplane for (1) reduced pressure in the first bypass engine operating condition to induce flow turning and (2) axially symmetrically equal pressure in the second bypass engine operating condition. 3. The jet propulsion device as defined in claim 2, wherein the first bypass engine operating condition includes the nozzle pressure ratio being below a threshold allowing unchoked flow through the throat region and an exit of the nozzle. 4. The jet propulsion device as defined in claim 3, wherein the second bypass engine operating condition includes the nozzle pressure ratio being above the threshold creating a sonic wave for choked flow through the throat region. 5. The jet propulsion device as defined in claim 2, wherein the midplane is vertical and a selected portion having maximum con-di is a bottom portion of the nozzle for downward vectoring of flow in the first bypass engine operating condition. 6. The jet propulsion device as defined in claim 5, wherein the core cowl has a symmetrical curvature and an exit of the fan sleeve is not aligned with a constant nacelle station having an exit. 7. The jet propulsion device as defined in claim 5, wherein the core cowl has a symmetrical increased curvature and the fan sleeve has decreased asymmetrical con-di in the fan sleeve. 8. The jet propulsion device as defined in claim 5, wherein the core cowl has an asymmetric increasing curvature with a maximum curvature of the core cowl in the bottom portion of the nozzle. 9. The jet propulsion device as defined in claim 2, further comprising chevrons on an exit circumference of the nozzle. 10. The jet propulsion device as defined in claim 9, wherein the chevrons span a top portion of about 25%-50% of the exit circumference of the nozzle. 11. The jet propulsion device as defined in claim 2, wherein: the axially symmetrically equal pressure in the second operating condition occurs at a throat of the nozzle; andthe asymmetric con-di and the wall curvature varying angularly from the midplane provide an exhaust annulus downstream of the throat having a first portion more fully expanded than a second portion. 12. The jet propulsion device as defined in claim 11, the first portion of the exhaust annulus being more fully expanded than the second portion to reduce shock cell noise. 13. The jet propulsion device as defined in claim 11, the first portion of the exhaust annulus being more fully expanded than the second portion to dissipate a shock cell train more rapidly relative to the exhaust annulus being symmetrically expanded. 14. The jet propulsion device as defined in claim 1, wherein the exhaust duct includes an outlet region; and the throat region is located in the outlet region of the exhaust duct. 15. The jet propulsion device as defined in of claim 14, wherein the throat region comprises a section of wall surfaces of the exhaust duct transitioning in a non-uniform manner, the section being located in the outlet region of the exhaust duct. 16. The jet propulsion device as defined in claim 1, wherein a difference between a planar angle of the exit vector at the first bypass engine operating condition and the second bypass engine operating condition is in a range of between 0 to 5 degrees. 17. A jet propulsion device, having a flow vectoring duct, the jet propulsion device comprising: a substantially annular exhaust duct surrounding a jet engine center body forming a pair of concentric opposing inner and outer walls;a throat region substantially symmetrically positioned in the outer wall of the exhaust duct forming a region of convergence, where the inner and outer walls converge, an amount of convergence varying longitudinally along the inner and outer walls; and a region of divergence, where the inner and outer walls diverge, an amount of divergence varying longitudinally along the inner and outer walls, an exit vector of an outlet plume at a first bypass engine operating condition is different than the exit vector at a second bypass engine operating condition, wherein a first transition from the first bypass engine operating condition to the second bypass engine operating condition at which differential directing of the plume occurs corresponds to a second transition between unchoked operation of a nozzle of the exhaust duct and choked operation of the nozzle of the exhaust duct. 18. The jet propulsion device as defined in claim 1, wherein the low speed operation comprises at least one of take-off or approach. 19. The jet propulsion device as defined in claim 18, wherein the high speed operation comprises at least one of cruise or climb. 20. The jet propulsion device as defined in claim 1, further comprising an outlet not aligned with a constant nacelle station. 21. The jet propulsion device as defined in claim 1, further comprising an outlet having chevrons. 22. The jet propulsion device as defined in claim 1, wherein the amount of convergence varying longitudinally along the inner and outer walls and the amount of divergence varying longitudinally along the inner and outer walls creates (1) an equalized pressure in the throat region when in a choked condition and (2) an non-equalized pressure region downstream of the throat region when in the choked condition. 23. The jet propulsion device as defined in claim 22, wherein the non-equalized pressure region weakens a shock cell. 24. The propulsion device as defined in claim 1, wherein the exhaust duct includes a fixed geometry differential vectoring nozzle, the nozzle comprising: a first wall portion having a first curvature and a first exit; anda second wall portion having a second curvature and a second exit varying longitudinally with respect to the first curvature to induce (1) lower pressure proximate the second wall portion relative to pressure proximate the first wall portion in the first bypass engine operating condition and (2) substantially equal pressure proximate the first and second wall portions in the second bypass engine operating condition. 25. The propulsion device as defined in claim 24, wherein the second curvature of the second wall portion is increased relative to the first wall portion. 26. The propulsion device as defined in claim 24, wherein the second exit of the second wall portion is extended longitudinally beyond the first exit of the first wall portion. 27. The propulsion device as defined in claim 24, wherein the first operating condition is unchoked flow and the second operating condition is choked flow. 28. A method for fan nozzle plume vectoring in a turbofan engine, the method comprising: providing a fan nozzle having an asymmetric convergence and divergence (con-di) section with greater con-di in a bottom portion of the fan nozzle relative to a top portion;operating the fan nozzle below a choke threshold to reduce pressure in the bottom portion of the fan nozzle having greater con-di for differentially inducing circumferential flow resulting in the fan nozzle flow being vectored toward the bottom portion; and,operating the fan nozzle above the choke threshold for substantially uniform pressure across the con-di section to produce substantially axial flow. 29. The method of claim 28, wherein providing the fan nozzle having the asymmetric con-di section comprises: creating the con-di section with a substantially axially symmetric inner nozzle wall with a curvature and a first exit not aligned with a constant nacelle station outer nozzle wall having a second exit varying angularly about a midplane from minimum divergence at 20° from top midplane to a maximum divergence approaching bottom midplane. 30. The method of claim 28, further comprising providing chevrons adjacent the top portion of the fan nozzle to induce vortical mixing for reducing a velocity gradient across a plume to supplement the vectoring of the nozzle flow. 31. The method of claim 28, further comprising operating the fan nozzle above the choke threshold for a non-uniformly expanded nozzle to weaken shock cell noise. 32. A method comprising: positioning a jet engine having a bypass duct beneath a wing such that unvectored jet exhaust flow from the bypass duct in a choked condition is proximate a trailing edge flap of the wing; andcontouring a predefined portion of the bypass duct distal to the trailing edge flap to redirect and vector a portion of the air flow in the bypass duct in an unchoked condition away from the trailing edge flap to reduce an interaction between the jet exhaust and the trailing edge flap. 33. A method for vectoring flow in a fixed geometry nozzle comprising: configuring a nozzle with convergence and divergence and an exit position providing an asymmetrical sectional area ratio from a first portion of the nozzle to a second portion of the nozzle;operating the nozzle in a choked condition with an exit flow from the nozzle being substantially axial; andoperating the nozzle in an unchoked condition for differential vectoring of the exit flow from the first portion of the nozzle toward the second portion. 34. The method of claim 33, further comprising reducing shock cell noise when operating the nozzle in the choked condition by generating an exhaust annulus having (1) a first portion of a first pressure at a region downstream of a throat and (2) a second portion of a second pressure at the region downstream of the throat, the second pressure being less than the first pressure.
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이 특허에 인용된 특허 (6)
Hebert, Leonard J., Convergent/divergent segmented exhaust nozzle.
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