CA2021086A1 - Exhaust nozzle hinge - Google Patents
Exhaust nozzle hingeInfo
- Publication number
- CA2021086A1 CA2021086A1 CA 2021086 CA2021086A CA2021086A1 CA 2021086 A1 CA2021086 A1 CA 2021086A1 CA 2021086 CA2021086 CA 2021086 CA 2021086 A CA2021086 A CA 2021086A CA 2021086 A1 CA2021086 A1 CA 2021086A1
- Authority
- CA
- Canada
- Prior art keywords
- wall sections
- upstream
- air flow
- hinge
- cooling air
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02K—JET-PROPULSION PLANTS
- F02K1/00—Plants characterised by the form or arrangement of the jet pipe or nozzle; Jet pipes or nozzles peculiar thereto
- F02K1/78—Other construction of jet pipes
- F02K1/80—Couplings or connections
- F02K1/805—Sealing devices therefor, e.g. for movable parts of jet pipes or nozzle flaps
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02K—JET-PROPULSION PLANTS
- F02K1/00—Plants characterised by the form or arrangement of the jet pipe or nozzle; Jet pipes or nozzles peculiar thereto
- F02K1/06—Varying effective area of jet pipe or nozzle
- F02K1/12—Varying effective area of jet pipe or nozzle by means of pivoted flaps
Abstract
EXHAUST NOZZLE HINGE
ABSTRACT OF THE DISCLOSURE
A hinge for pivotably connecting upstream and downstream wall sections of an exhaust nozzle of a gas turbine engine. Each wall section includes a liner spaced from the interior surface of the wall section to define respective first and second cooling air flow passages therebetween. One of the wall sections includes a curved end portion and the hinge includes a leaf seal which extends from the other wall section and biases against the curved end portion to form an air tight seal and define, at least in part, a plenum at the hinged connection of the wall sections. The plenum provides an air flow communication path between the first and second cooling air flow passages to transfer cooling air from the air flow passage of the upstream wall section to the air flow passage of the downstream wall section to thereby increase the efficiency of cooling of each of the wall sections.
ABSTRACT OF THE DISCLOSURE
A hinge for pivotably connecting upstream and downstream wall sections of an exhaust nozzle of a gas turbine engine. Each wall section includes a liner spaced from the interior surface of the wall section to define respective first and second cooling air flow passages therebetween. One of the wall sections includes a curved end portion and the hinge includes a leaf seal which extends from the other wall section and biases against the curved end portion to form an air tight seal and define, at least in part, a plenum at the hinged connection of the wall sections. The plenum provides an air flow communication path between the first and second cooling air flow passages to transfer cooling air from the air flow passage of the upstream wall section to the air flow passage of the downstream wall section to thereby increase the efficiency of cooling of each of the wall sections.
Description
~02~8~ -E~ST NOZZLE HINGE
The invention described herein was made in the course of, or under, United State~ Department of the Air Force Contract No.
F33657-83-C-0281. The United States Government has rights in this invention pursuant to said contract.
BACRGROUND OF THE INVENTION
Field of the Invention The present invention relates to hinges for pivotably connecting axially adjacent upstream and downstream wall sections of a gas turbine engine exhaust nozzle, and particularly to a nozzle hinge having a novel configuration for transferring cooling air from the upstream wall section to the downstream wall section.
Description of the Related Art Maneuverability of modern high performance aircraft is greatly enhanced by extending the role of ~he engine exhaust nozzle beyond its con~entional jet accelerating function. An exhaust nozzle with jet deflection capability can produce more ; rapid aircraft maneuvers at lower fligh~ speeds than can be achieved by conventional control surfaces. In addition, reverse ~;~ thrust capabllity incorporated within the exhaust nozzle can ~; 20 enable the aircraft to decelerate very rapidly for in-fligh~
maneuvering purposes, and also to decelerate on landing to reduee the landing roll for short field operation.
Exhaust nozzles capable of such additional functions are know as multi-function exhaust nozzles. A typical such exhaust - ~ 25 nozzle 10 is illustrated ln Fig. 1. Nozzle 10 is a two dimensional exhaust nozzle having wall sections comprised of side .
The invention described herein was made in the course of, or under, United State~ Department of the Air Force Contract No.
F33657-83-C-0281. The United States Government has rights in this invention pursuant to said contract.
BACRGROUND OF THE INVENTION
Field of the Invention The present invention relates to hinges for pivotably connecting axially adjacent upstream and downstream wall sections of a gas turbine engine exhaust nozzle, and particularly to a nozzle hinge having a novel configuration for transferring cooling air from the upstream wall section to the downstream wall section.
Description of the Related Art Maneuverability of modern high performance aircraft is greatly enhanced by extending the role of ~he engine exhaust nozzle beyond its con~entional jet accelerating function. An exhaust nozzle with jet deflection capability can produce more ; rapid aircraft maneuvers at lower fligh~ speeds than can be achieved by conventional control surfaces. In addition, reverse ~;~ thrust capabllity incorporated within the exhaust nozzle can ~; 20 enable the aircraft to decelerate very rapidly for in-fligh~
maneuvering purposes, and also to decelerate on landing to reduee the landing roll for short field operation.
Exhaust nozzles capable of such additional functions are know as multi-function exhaust nozzles. A typical such exhaust - ~ 25 nozzle 10 is illustrated ln Fig. 1. Nozzle 10 is a two dimensional exhaust nozzle having wall sections comprised of side .
2~210~6 13~V-9099 walls 12, upstream converging flaps 14, and downstream diverging flaps 16 and 16a disposed between side walls 12. Such two~
dimensional nozzles are preferred for multi-function applications since, unlike round section, axisymmetric nozzles, flaps 16 S and 16a may be actuated differentially to thereby deflect the stream of hot combustion gases exiting through the nozzle for rapid pitch maneuvering of the aircraft. Such di ferential actu-ation of flaps 16 and 16a is illustrated in Fig. 3. Fig. 2 illus-trates the position of flaps 16 and 16a for normal thrust operation. ~ig. 3 illustrates the deflected positions of flaps 16 and 16a for rapid pitch maneuvering of the aircraft. Fig. 4 illustrates a closed position of flaps 14, 16, and 16a wherein the hot combustion gases are discharged through auxiliary exhaust nozzles 18 to produce a reverse thrust.
Since the wall sections of the exhaust nozzles are exposed to extremely high ~emperatures from the stream of hot products of combustion exhausting through nozzle 10, it is preferable to cool the interior surfaces of the wall sections to extend the service life of the nozzle and reduce maintenance requirements.
2~ Typically, prior art nozzles utilized a surface cooling configu-ration for the wall sections of the nozzles as illustrated in Fig. 5. Fig. 5 schematically illustrates a portion of exhaust no2zle lO including a casing section 20 positioned upstream of converging flap 14 in the hot gas flow path. Casing 20 includes a liner 22 spaced from the interior surface thereof. cooling air, typically bypass air from the turbine engine, is injected into ; cooling air flow passage 24 between casing section 20 and ::
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liner 22. The cooling air is ejected from cooling air flow passage 24 along the interior surfaces of flaps 14 and 16 to provide a film of cooling air on the interior surfaces of those flaps as illustrated by the arrows in Fig. 5.
However, the Fig. ~ configuration has significant drawbacks.
First, the cooling air exiting from cooling air flow passage 24 is depleted as it flows along the surfaces of flaps 14, 16, and 16a by mixing with hot ga~es in the exhaust gas flow path. This depletion of the cooling air results in an excessive amount of lo cooling air flow being required to cool the flap sections 14, 16 and 16a. Excessi.ve cooling air flow results in performance loss since the cooling air flow is typically taken from the turbine engine bypass air. Moreover, and with reference to Fig. 6, when flaps 14, 16, and 16a are deflected for pitch maneuvering of the aircraft, a severe anqle exists at the junction of the convergent flaps 14 and divergen~ flaps 16 and 16a resulting in local flow separation 28 downstream of throat 30. Interior surfaces of flaps 16 and 16a, which depend on the conventional film of cooling air injected upstream of the flap for cooling, overheat since ~he turbulence in separated flow region 28 mixes the film of cooling air with hot gas flowing through the exhaust nozzle and thereby seriously diminishes the effectiveness of this type of cooling configura~'on.
Although ~he problem of cooling nozzle wall sections is equally applicable to axisymmetric nozzles as to multi-function, two-dimensional type exhaust nozzles, pro~lems associated with cooling the rearmost, divergent nozzle flap on a multi-functiOn .,~ .
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~21~86 two-dimensional type exhaust nozzle are magnified for two basic reasons. First, divergent flaps on two-dimensional type nozzles are longer for a given nozzle size and flow area than axisymmetric nozzle flaps and, thus, are more difficult to cool by the conven-tional method of in~ecting a f ilm of cooling air at the flaphinge. The flaps of two-dimensional exhaust nozzles are longer than axisymmetric nozzle flaps since the-side walls of the two-dimensional nozzle are fixed and the flap ~otion m~st therefore provide all of the required nozzle area variation. Two-dimensional nozzle flaps, the tips of which travel through a greater excursion to provide the required area variation, must necessarily be longer so that nozzle flap external contour angles are low as required for low drag and thus high performance of the aircraft.
Secondly, and in conjunction with the reasons noted above, during operation of a two-dimensional type exhal~st nozzle with full jet deflection, a severe angle exists at the junction of the con~ergent and divergent f laps resulting in local flow separation - ~downstream of the throat as described above with reference to FLg. 6.
In practice, two-dimensional exhaust nozzle flaps cooled by a film of cooling air injected at the hinge are subjected to exces-sive and nonuniform temperatures due ~o the general inefficiency ;~ of this type of film injected cooling flow. Such inefficiency has resulted in distortion, thermal fatigue, and crackinq of the flap surface on some exhaust nozzles currently in operational service.
Furthermore, as overall engine efficiency is increased in response . ~:
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the aircraft, the availability of bypass air for cooling the exhaust nozzle flaps is becoming increasingly scarce. To provide adequate temperature control of nozzle flaps on modern engines, a more efficient convec~ion cooling means is required which, in general, can provide for more uniform distribution of cooling air over the wall sections of the nozzle.
Therefore, it is an object of the present invention to provide a hinge for pivotably connecting upstream and downstream exhaust no~zle wall sections wherein cooling air may be more efficiently transferred from the upstream to the downstream wall sections of the nozzle.
It is a further object of the present invention to provide a hinge connection for adjacent upstream and downstream wall sections of an exhaust nozzle which accommodates ~he use of liners disposed on the interior surfaces of the wall sections of the nozzle to define cooling air flow passages therebetween.
It is still a further object of the present invention to - provide a hinge for adjacent upstream and downstream wall sections of a nozzle which is capable of more efficiently transferring -20 cooling air along the upstream and downstream interior surfaces of the nozzle wall sections to thereby reduce the demand for cooling air flow resulting in increased performance and efficiency of the aircraft prime mover.
Additional objects and advan~ages of the invention will be set forth in the description which follows, and in part will be obvious from the desGription, or may be learned by practice of the invention. The objects and advantages of the invention may be ;~ 5 :~ :
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13~V-9099 realized and attained by means of the instrumentalities and combi-nations particularly pointed out in the appended claims.
SUMMARY OF THE INVENTION
To achieve the foregoing ob~ects, and in accordance with th~
purpo~es of the invention as em~odied and broadly described herein, a hinge is provided for connecting a first wall section and a second wall section of a gas turbine engine exhaust nozzle and for allawing relatire pivoting mo~ion therebetween. The first and second wall sections each ha~e an inside surface and a liner attached to and spaced apart from the inside surface for defining first and second cooling air flow passages therebetween. The hinge comprises a curved end portion having a curved surface formed at a first end of one of the first and second wall sections, and leaf seal means, fixedly attached to and extending from a first end of the other one of said first and second wall sections, for slidably bearing against the cur~ed surface to form -~ a substantially air-tight seal therebetween as the first and second wall sections pirot relatire to one another. Plenum means, defined at least in part by the leaf seal means and the first end of the other one of the first and second wall sections, provides a flow communication between the first and second cooling air flow passages, and offset brac~et means are prorided for pivotably connecting the first and second wall sections at respective first ends of the wall sections.
Preferabl-~, the first wall section is positioned upstream of the second wa~l section in the gas flow path through the exhaus~
:, nozzle and the curred surface is formed at the upstream end of the :, ~ 6-~'~' , .
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~2~6 ,` l~DV-9099 second wall section. The liner of the second wall section is then configured to include a curved upstream end portion spaced from the curved portion of the second wall section to define a portion of the cooling air flow passage of the second wall section. With such a configuration, the liner of the first wall section is configured with a downstream end portion terminating proximate to, spaced from, and in sealing engagement with the curved end portion of the liner of the second wall section. ~n this manner, as the flrst and second wall sections pivot relative to one another the curved upstream end portion of the liner of the second wall section follows and remains proxLmate to and in sealing engagement with to the downstream end portion of the liner of the first wall section to maintain a continuous flow path from the first cooling air flow pa sage, through the plenum means, to the second cooling air flow passage without significant leaks therethrough.
BRIEF DESCRIPTION OF THE DR~NINGS
The accompanying drawings, which are incorporated in and con-stitute a part of the specification, illustrate a preferred ; embodLment of the invention and, together with the general des-cription given above and the detailed description of the preferred embodiment given below, serve to explain the principles of the invention.
Fig. 1 is a perspective view of a typical two-dimensional converging/diverging exhaust nozzle;
Fig. 2 is a schematic side view of the nozzle of Fig. 1 with the flaps of the nozzle positioned for full jet thrust;
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~ -7-~2~g6 Fig. 3 is a schematic side view of the nozzle of Fig. 1 wi~h the flaps of the nozzle deflected for pitch maneuvering of the aircraft;
Fig. 4 is a schematic side view of the nozzle of Fig. 1 with the nozzle flaps in a closed position to direct the exhaust gases through auxiliary nozzles which provide reverse thrust for short :
field operations;
Fig. 5 is a schematic side view of a conventional film type cooling airflow configuration across convergent and divergent lo flaps of a two-dimensional exhaust nozzle;
Fig. 6 is a schematic representation of the flow of film cooling air across the interior surfaces of the two-dimensional nozzle of Fig. 5 which illustrates the area of flow separation downstream of the hinge connection when the divergent and conver-i~
gent flaps are deflected for pitch maneuvering of the aircraft;
Fig. 7 is a detailed side view of an exhaust nozzle hingeincorporating the teachings of the present invention wherein the wall sections of the nozzle are fully closed for reverse thrust operation;
2u Fig. 8 is a detailed side view of the exhaus~ nozzle hinge of Fig. 7 wherein the wall sections of the nozzle are positioned for deflection of the exhaust gas flow path for pitch maneuvering of .
the aircraft;
Fig. 9 is a partial isometrLc view of the exhaust nozzle hinye of Fig. 7 illustrating the pivoting bracket connection of the wall sections of the nozzle;
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~2~ ~6 Fig. 10 is a partial side view of the exhaust nozzle hinge of Fig. 7;
Fig. ll is a partial top view of the exhaust nozzle hinge of Fig. 7; and ~ ~ Fig. 12 is a schematic representation of a portion of an - exhaust nozzle wherein hinges incorporating the teachings of the present invention are incorporated at the connection of convergent and divergent flaps and at the connection of the convergent flap with the nozzle casing.
o DESCRIPTION OF THE PREFERRED EMBODIMENT
Reference will now be made in detail to the present preferred embodiment of the invention as illustrated in the accompanying drawings. It is here noted that the present invention is equally applicable to axisymmetric type exhaust nozzles as to multi-i5 function, two-dLmensional exhaust nozzles hereinbefor- described.
However, for purposes of desoribing the present preferred embodi-- ~ ment of the invention, and not by way of limitation, the descrip-tion below is directed primarily to a hinge incorporating the teachings of the present invention which connects first and second wall sections of a two-dimensional type exhaust nozzle. Further-more, while a plurality of hLnges of the present invention may be incorporated in a given exhaust nozzle to connect the various pivoting wall sections, each hinge would have s~ubstantially the same configuration, thus, only one such hinge is described herein-below. It will be apparent to those skilled in the art that thedescription of the hinge connection f or pivoting wall sections of the two-dLmensional nozzle is equally applicable to connections of _g_ `. ~
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wall sections of an axisymmetric type nozzle and o~her ~ariations on multifunction type exhaust nozzles.
In accordance with the present invention, a hinge means i~
provided for connecting a first wall section and a second wall section of an exhaust nozzle. As embodied herein, and as illus-trated in Figs. 7 and 8, the hinge means includes a hinge generally referred to as 100. Hinge 100 connects a first wall ~ection 102 and a second wall section 104 and allows relative pivoting motion between first wall section 102 and second wall lo section 104. First and second wall sections 102 and 104 each have an inside surface 106 and 108, respectively. Wall sections 102 and 104 further include liners 110 and 112, respectively, spaced from inside surfaces 106 and 108 to define cooling air flow passages 11~ and 116 therebetween.
In accordance with the preqent invention, the hinge comprises a curved portion formed at a first end of one of the first and second wall sections. In the preferred embodiment of the present ~ invention illustrated in Figs. 7 and 8, curved portion 118 is ~; formed at a first end 120 of second wall section 104.
` 20 In accordance with the present invention, the hinge further includes seal means for forming a substantially air tight seal between the curved portion of the second wall section and a firs~
end of the first wall section as the first and second wall sections pivot relative to one another. Preferably, the seal mea~s compr~ses a leaf seal means, fixedly attached to and extending from one of the wall sections, for slidably bearing against the other wall section to form a substantially airtight ~' ~. .. ,. - : :
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seal therebetween as the first and second wall sections pivot relative to one another. As embodied and illustrated in Fig. 7, - the leaf seal means is fixedly attached to a first end 121 of wall ~ection 102 and includes leaf seal 122 having a root portion 124 and a biasing portion 126 cantilevered from root portion 124.
Bia~ing portion 126 includes a distal end portion 128. Root portion 124 of leaf seal 122 is attached ~o first end 121 of wall section 102 via a bracket 130. Root portion 124 is firmly fixed to bracket 130 by a bolted connection 132. Alternatively, root portion 124 may be attached to bracket 130 by welding or any other fastening means. Bracket 130 is in turn fixedly attached to wall section 102 by a bolted connection 134. Bracket 130 is of course not limited to being connected to wall section 102 by bolt 134 and may also be welded to wall section 102 or attached by any other lS known fa~tening means. Alternatively, root portion 124 may be fixedly attached directly to wall section 102. In the present preferred embodiment bracket 130 serves to position and support biasing portion 126 of leaf seal 122 in the desired position as will be discussed hereinafter.
~; 20 With the configuration of leaf seal 122 and bracket 130 as shown in Figs. 7 and 8, the distal end 128 of biasing portion 126 conforms to, and slidably bears against, cur~ed portion 118 of second wall section 104 as wall sections 102 and 104 pivot ~; relatiYe to one another thereby forming an airtight seal between -~ 25 biasing portion 126 and cur~ed portion 118.
In accordance with the present invention, the hinge further ;.: : . ,; includes plenum means, defined at least in part by the leaf seal :~.
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means and a first end of one wall section, for flow communicating the firs~ and second cooling air flow passages. As embodied herein, and as shown in Figs. 7 and 8, the plenum means comprises a plenum 136 defined a~ least in part by first end 121 of wall section 102 and leaf seal 122. Each of wall sections 102 and 104 have a width along respective first ends 120 and 121 thereo~ sub-stantially commensurate with one another. Liners 110 and 11~ also have a width substantially commensurate wi~h the widths of wall sections 102 and 104. Plenum 136 extends along substantially the entire width of first ends 120 and 121 of first and second wall sections 102 and 104, respectively, to form a continuous air flow path between first cooling air flow passage 114 and sesond cooling air flow passage 116 through plenum 136 along substantially the entire width of wall sections 102 and 104. The airflow path of cooling air through the cooling air flow passages and plenum is , .~
illustrated in Fig. 7 with arrows 138. Thus, since plenum 136 connects cooling air flow passages 114 and 116 along substantially the entire width of wall sections 102 and 104, uniform flow of cooling air through the plenum and along the wall sections is obtained without mixing with the hot exhaust gases exiting through the nozzle.
In accordance with the present in~ention, the hinge further includes offset bracket msans for pivotably connecting the first and second wall sections at respective first ends thereof. As embodied herein, the offset bracket means includes at least two brackets 140. With reference to Figs. 9 and 11, bracket 140 includes a base portion 142 and an arm portion 144 extending from ' ' ~ ' . : ~' .. , : -~ .. .. .. :
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base portion 142. ~ase portion 142 is fixedly attached to first end 121 of wall section 102 by welding or by any other suitable fastening means. Each of the at least two brackets 140 are spaced from one another along the width of first end 121 of wall section 102. Arm portion 144 of bracket 140 includes a distal end portion 146 having an aperture 148. Distal end portions 146 of e~ch bracket are thus offse~ by the length of arm portion 144 from wall section 102. In this manner the brackets 140 provide a con-.~ figuration for pivotably connecting the first and second wall sections while stepping over curved end portion 118 as discussed below.
Ribs 1~0 are fixedly attached to wall section 104 proximate first end 120 by welding, for ex~mple. Each pair of ribs 150 are spaced to receive distal end portion 146 of bracket 140 therein and includes apertures 151 which align with aper ure 148 when : distal end portion 146 is received between ribs 150. Wall section 104 is pivota~ly attached to distal end 146 of arm portion 144 by means of pins 152 which extend through aperture 148 of bracket 140 and apertures 151 of ribs 150 to connect wall sections 102 and 104 in an assemhled state.
The configuration of the offset bracket means permits wall sections 102 and 104 to pivot relative to one another to different : angular orientations in accordance with the opera~ing condition of ; : the nozzle while stepping over curved portion 118 of wall section 104. In this manner, curved portion 118 remains spaced ~ ~ from first end 121 of wall s~ction 102 to partially define ::;~ plenum 136. Moreover, while Fi~. 9 illustrates at least two ~: :.
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, ~, brackets 140, each is substantially identical in construction, thus, only one has been described abo~e. Furthermore, any number of brackets 140 may be arranged along the first ends of wall sections 102 and 104 to pivotably connect the wall sections in the S assembled state and securely support the same. The present invention is not limited to the specific configuration of the bracket 140 shown and described and numerous other configurations for the offset bracket means will be envisioned by those skilled in the art while remaining within the scope of the present lnvention.
With reference to Figs. 7 and 8, liner 112 of wall section 104 includes a curved upstream end portion 154 spaced from curved portion 118 of second wall section 104 to thereby define the upstream-most portion of cooling air flow passage 116.
15 Liner 110 includes a downstream end portion 156 terminating proximate to and spaced from curved end portion 154 of liner 11 to define an airflow path 158 therebetween.
Airflow path 158 between curved upstream end por~ion 154 of liner 112 and downstream end portion 156 of liner 110 may be ' 20 dimensioned to control the amount of coolant air leakage from plenum 136 and to eject a thin film of cooling air along the , . .
surface of liner 112 as indicated by arrow 160. Alternatively, hinge 100 may be configured with a means for sealing airflow path 158. As embodied herein, the sealing means may incorporate a . .
leaf spring 162 fixedly attached to downs~ream end portion 156 of `~ ~ liner 110 wherein a leaf 164 of Ieaf spring 162 is configured to . ' .
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13~V-9099 bias against curved upstream end portion 154 of liner 112 to thereby seal airflow gap 158.
Cur~ed portion 118 of wall section 104 includes at leas~ two notched portions 166 illustrated by dotted lines in Fig. 8.
Notched portions 165 are spaced from one another along the width of wall section 112 to correspond to arm portions 144 of brackets 148. Arm portions 144 are movable into and out of notched portions 166 of curved portion 118 as first and second ~ wall sections 102 and 104 pivot relative to one another about ~he ; 10 offset bracket means. When wall sections 102 and 104 are positioned relative to one another such that the exhaust nozzle is in a fully deflected configuration as shown in Fig. 3, curved upstream end portion 154 of liner 112 extends upward into plenum 136 and arm portions 144 move into notched portions 166. In this position the flow path of cooling air through air flow passage 114 is into plenum 136 and then around the end of curved upstream end portion 154 and back down and into cooling air flow passage 116 as again illustrated by arrows 138.
~, With reference to Fig. 9, leaf seals 122 extend along the , ~,, width of wall sections 102 and 104 and are interrupted by brackets 140 spaced across the width of wall sec~ion 102. In this i:
manner leaf seals 122 do not interfere with bracXets 140 as wall sections 102 and 104 pivot relative to one another. To control leakage from plenum 136 through notched portions 166, local 25 appendages 16B are attached to distal end 128 of cantilevered portion 126 of each leaf seal to bridge notch portions 166 and ~, seal plenum 136 as first and second wall sections 102 and 104 ~. ~
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'-` ~ 13DV-9099 pivot about the offset bracket means to progressively larger angles therebetween. In this manner, potential leakage loss o~
cooling air from plenum 136 is minimized by sealing notch i portions 166 with appendages 168 as the wall sections pivot relative to one another and curved end portion 118 of wall section 104 for each of the angular orientations of the wall sections. Similarly, leakage through air gap 158 between down-stream end portion 156 of liner 110 and curved upstream end portion 154 of liner 112 may be minimized by incorporation of leaf spring 162 across gap 158.
A third potential leakage point of cooling air from plenum 136 exists at the endmost connections of wall section 102 and 104 where these endmost connections abut adjoining wall sections. To minimize leakage of cooling air from the dis~al ends of plenum 136, an end cap 170 is attached to each distal edge of the first end 120 of wall section 102, as illustrated in Figs. 9 ; and 10, to seal plenum 136 at the ends thereof. End cap 170 fits closely with the end of leaf seal 122 and bracket 130 to minimize ~ loss of coolant air flow between the mating surfaces thereof. To ; 20 control leakage at the interface of wall sections 102 and 104 and a side wall 172 of the nozzle, a cylindrical seal 174 is inserted in each endmost portion of the curved portion 118 of wall section 104. A spring 176 may be inserted within each cylindrical ; seal 174 to bias against an abutment 177 and urge each cylindrical seal towards a respective side wall 172 of the nozzle. Here again, since the end caps 170 and as~ociated cylindrical seals 174 disposed at each outermost edge of wall sections 102 and 104 are ~; .
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2a2l0~6 substantially identical in construction, only one edge configura-tion is illustrated and described herein.
In the preferred embodlment of the present invention described hereinabove, wall section 104 comprises a diverging flap S of a two-dimensional exhaust nozzle and wall section 102 comprises a converging flap of the exhaust nozzle. The con~erging flap 102 i9 positioned upstream of diverging flap 104 in the exhaust gas flow path through the nozzle. Liners 110 and 112 o~ converging and diverging flaps 102 and 104 define a portion of the gas flow lo path through the nozzle. However, the present invention is not limited to use at the connection between converging and diverging flaps of a two-dimensional nozzle. Alternatively, as illustrated schematically in Fig. 12, the teachings of the present invention may be incorporated at a hinge connection between a nozzle casing lS section and the converging wall section, such as in hinge connection 200 between nozzle casing section 202 and converging wall section 102. A liner 204 is spaced from casing section 202 to define a cooling air flow pa~sage 206 therebetween. In this em~odiment, cooling air flowing through passage 206 arrives in plenum 208 at hinge connection 200 and from plenum 208 passes into cooling air flow passage 114 along substantially the entire width of convergen~ wall section 102 and into plenum 136 of hinge lO0.
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; From plenum 136 cooling air flows into cooling air flow passage l16 of divergen~ wall section 104. Thus the present invention may be incorporated at each pivota~le connection of respective wall sections defining the exhaust nozzle gas flow ~, path.
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-Furthermore, the preferred embodiment of the present invention has been described hereinabove with curved portion 118 formed at first end 120 of wall section 104 and with the leaf seal means fixedly attached to and extending from first end 121 of wall section 102. However it is well within the scope of the present invention that the curved portion be formed at first end 121 of wall section 102 with the leaf seal means and the offset bracket means extending from first end 120 of wall section 104. With such an arrangement the plenum means is still defined at least in part by the leaf seal means and the first end of one of the wall sections, and coolin~ air flow is directed from cooling air flow passage 114 into plenum 136 and therefrom into cooling air flow passage 116.
The present invention provides a novel configuration of an exhaust nozzle hinge capable of transferring cooling air flow from an upstream cooling air flow passage defined by a liner spaced from the upstream wall section, to a downstream cooling air flow passage defined by a liner spaced from the downstream wall section. This arrangement allows for more efficient use of ~; ~o cooling air passing throuqh the cooling air flow passages and is particularly applicable to two-dimensional exhaust nozzles wherein the diverging flaps are of relatively long length. Through use of the pre~ent invention avoidance of thermal distortion and fatigue, and generally improved maintainability of the wall section5 of the exhaust nozzle may be obtained.
- Additional advantages and modifications will readily occur to those skilled in the art. The invention in its broadest aspects ~` :
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is, therefore, not lLmited to the specific details, representative apparatus and illu~trative examples shown and described.
Accordingly, departures may be made from such details without departinq from the spirit or scope of the applicants' inventive S concept.
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dimensional nozzles are preferred for multi-function applications since, unlike round section, axisymmetric nozzles, flaps 16 S and 16a may be actuated differentially to thereby deflect the stream of hot combustion gases exiting through the nozzle for rapid pitch maneuvering of the aircraft. Such di ferential actu-ation of flaps 16 and 16a is illustrated in Fig. 3. Fig. 2 illus-trates the position of flaps 16 and 16a for normal thrust operation. ~ig. 3 illustrates the deflected positions of flaps 16 and 16a for rapid pitch maneuvering of the aircraft. Fig. 4 illustrates a closed position of flaps 14, 16, and 16a wherein the hot combustion gases are discharged through auxiliary exhaust nozzles 18 to produce a reverse thrust.
Since the wall sections of the exhaust nozzles are exposed to extremely high ~emperatures from the stream of hot products of combustion exhausting through nozzle 10, it is preferable to cool the interior surfaces of the wall sections to extend the service life of the nozzle and reduce maintenance requirements.
2~ Typically, prior art nozzles utilized a surface cooling configu-ration for the wall sections of the nozzles as illustrated in Fig. 5. Fig. 5 schematically illustrates a portion of exhaust no2zle lO including a casing section 20 positioned upstream of converging flap 14 in the hot gas flow path. Casing 20 includes a liner 22 spaced from the interior surface thereof. cooling air, typically bypass air from the turbine engine, is injected into ; cooling air flow passage 24 between casing section 20 and ::
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liner 22. The cooling air is ejected from cooling air flow passage 24 along the interior surfaces of flaps 14 and 16 to provide a film of cooling air on the interior surfaces of those flaps as illustrated by the arrows in Fig. 5.
However, the Fig. ~ configuration has significant drawbacks.
First, the cooling air exiting from cooling air flow passage 24 is depleted as it flows along the surfaces of flaps 14, 16, and 16a by mixing with hot ga~es in the exhaust gas flow path. This depletion of the cooling air results in an excessive amount of lo cooling air flow being required to cool the flap sections 14, 16 and 16a. Excessi.ve cooling air flow results in performance loss since the cooling air flow is typically taken from the turbine engine bypass air. Moreover, and with reference to Fig. 6, when flaps 14, 16, and 16a are deflected for pitch maneuvering of the aircraft, a severe anqle exists at the junction of the convergent flaps 14 and divergen~ flaps 16 and 16a resulting in local flow separation 28 downstream of throat 30. Interior surfaces of flaps 16 and 16a, which depend on the conventional film of cooling air injected upstream of the flap for cooling, overheat since ~he turbulence in separated flow region 28 mixes the film of cooling air with hot gas flowing through the exhaust nozzle and thereby seriously diminishes the effectiveness of this type of cooling configura~'on.
Although ~he problem of cooling nozzle wall sections is equally applicable to axisymmetric nozzles as to multi-function, two-dimensional type exhaust nozzles, pro~lems associated with cooling the rearmost, divergent nozzle flap on a multi-functiOn .,~ .
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~21~86 two-dimensional type exhaust nozzle are magnified for two basic reasons. First, divergent flaps on two-dimensional type nozzles are longer for a given nozzle size and flow area than axisymmetric nozzle flaps and, thus, are more difficult to cool by the conven-tional method of in~ecting a f ilm of cooling air at the flaphinge. The flaps of two-dimensional exhaust nozzles are longer than axisymmetric nozzle flaps since the-side walls of the two-dimensional nozzle are fixed and the flap ~otion m~st therefore provide all of the required nozzle area variation. Two-dimensional nozzle flaps, the tips of which travel through a greater excursion to provide the required area variation, must necessarily be longer so that nozzle flap external contour angles are low as required for low drag and thus high performance of the aircraft.
Secondly, and in conjunction with the reasons noted above, during operation of a two-dimensional type exhal~st nozzle with full jet deflection, a severe angle exists at the junction of the con~ergent and divergent f laps resulting in local flow separation - ~downstream of the throat as described above with reference to FLg. 6.
In practice, two-dimensional exhaust nozzle flaps cooled by a film of cooling air injected at the hinge are subjected to exces-sive and nonuniform temperatures due ~o the general inefficiency ;~ of this type of film injected cooling flow. Such inefficiency has resulted in distortion, thermal fatigue, and crackinq of the flap surface on some exhaust nozzles currently in operational service.
Furthermore, as overall engine efficiency is increased in response . ~:
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the aircraft, the availability of bypass air for cooling the exhaust nozzle flaps is becoming increasingly scarce. To provide adequate temperature control of nozzle flaps on modern engines, a more efficient convec~ion cooling means is required which, in general, can provide for more uniform distribution of cooling air over the wall sections of the nozzle.
Therefore, it is an object of the present invention to provide a hinge for pivotably connecting upstream and downstream exhaust no~zle wall sections wherein cooling air may be more efficiently transferred from the upstream to the downstream wall sections of the nozzle.
It is a further object of the present invention to provide a hinge connection for adjacent upstream and downstream wall sections of an exhaust nozzle which accommodates ~he use of liners disposed on the interior surfaces of the wall sections of the nozzle to define cooling air flow passages therebetween.
It is still a further object of the present invention to - provide a hinge for adjacent upstream and downstream wall sections of a nozzle which is capable of more efficiently transferring -20 cooling air along the upstream and downstream interior surfaces of the nozzle wall sections to thereby reduce the demand for cooling air flow resulting in increased performance and efficiency of the aircraft prime mover.
Additional objects and advan~ages of the invention will be set forth in the description which follows, and in part will be obvious from the desGription, or may be learned by practice of the invention. The objects and advantages of the invention may be ;~ 5 :~ :
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13~V-9099 realized and attained by means of the instrumentalities and combi-nations particularly pointed out in the appended claims.
SUMMARY OF THE INVENTION
To achieve the foregoing ob~ects, and in accordance with th~
purpo~es of the invention as em~odied and broadly described herein, a hinge is provided for connecting a first wall section and a second wall section of a gas turbine engine exhaust nozzle and for allawing relatire pivoting mo~ion therebetween. The first and second wall sections each ha~e an inside surface and a liner attached to and spaced apart from the inside surface for defining first and second cooling air flow passages therebetween. The hinge comprises a curved end portion having a curved surface formed at a first end of one of the first and second wall sections, and leaf seal means, fixedly attached to and extending from a first end of the other one of said first and second wall sections, for slidably bearing against the cur~ed surface to form -~ a substantially air-tight seal therebetween as the first and second wall sections pirot relatire to one another. Plenum means, defined at least in part by the leaf seal means and the first end of the other one of the first and second wall sections, provides a flow communication between the first and second cooling air flow passages, and offset brac~et means are prorided for pivotably connecting the first and second wall sections at respective first ends of the wall sections.
Preferabl-~, the first wall section is positioned upstream of the second wa~l section in the gas flow path through the exhaus~
:, nozzle and the curred surface is formed at the upstream end of the :, ~ 6-~'~' , .
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~2~6 ,` l~DV-9099 second wall section. The liner of the second wall section is then configured to include a curved upstream end portion spaced from the curved portion of the second wall section to define a portion of the cooling air flow passage of the second wall section. With such a configuration, the liner of the first wall section is configured with a downstream end portion terminating proximate to, spaced from, and in sealing engagement with the curved end portion of the liner of the second wall section. ~n this manner, as the flrst and second wall sections pivot relative to one another the curved upstream end portion of the liner of the second wall section follows and remains proxLmate to and in sealing engagement with to the downstream end portion of the liner of the first wall section to maintain a continuous flow path from the first cooling air flow pa sage, through the plenum means, to the second cooling air flow passage without significant leaks therethrough.
BRIEF DESCRIPTION OF THE DR~NINGS
The accompanying drawings, which are incorporated in and con-stitute a part of the specification, illustrate a preferred ; embodLment of the invention and, together with the general des-cription given above and the detailed description of the preferred embodiment given below, serve to explain the principles of the invention.
Fig. 1 is a perspective view of a typical two-dimensional converging/diverging exhaust nozzle;
Fig. 2 is a schematic side view of the nozzle of Fig. 1 with the flaps of the nozzle positioned for full jet thrust;
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~ -7-~2~g6 Fig. 3 is a schematic side view of the nozzle of Fig. 1 wi~h the flaps of the nozzle deflected for pitch maneuvering of the aircraft;
Fig. 4 is a schematic side view of the nozzle of Fig. 1 with the nozzle flaps in a closed position to direct the exhaust gases through auxiliary nozzles which provide reverse thrust for short :
field operations;
Fig. 5 is a schematic side view of a conventional film type cooling airflow configuration across convergent and divergent lo flaps of a two-dimensional exhaust nozzle;
Fig. 6 is a schematic representation of the flow of film cooling air across the interior surfaces of the two-dimensional nozzle of Fig. 5 which illustrates the area of flow separation downstream of the hinge connection when the divergent and conver-i~
gent flaps are deflected for pitch maneuvering of the aircraft;
Fig. 7 is a detailed side view of an exhaust nozzle hingeincorporating the teachings of the present invention wherein the wall sections of the nozzle are fully closed for reverse thrust operation;
2u Fig. 8 is a detailed side view of the exhaus~ nozzle hinge of Fig. 7 wherein the wall sections of the nozzle are positioned for deflection of the exhaust gas flow path for pitch maneuvering of .
the aircraft;
Fig. 9 is a partial isometrLc view of the exhaust nozzle hinye of Fig. 7 illustrating the pivoting bracket connection of the wall sections of the nozzle;
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~2~ ~6 Fig. 10 is a partial side view of the exhaust nozzle hinge of Fig. 7;
Fig. ll is a partial top view of the exhaust nozzle hinge of Fig. 7; and ~ ~ Fig. 12 is a schematic representation of a portion of an - exhaust nozzle wherein hinges incorporating the teachings of the present invention are incorporated at the connection of convergent and divergent flaps and at the connection of the convergent flap with the nozzle casing.
o DESCRIPTION OF THE PREFERRED EMBODIMENT
Reference will now be made in detail to the present preferred embodiment of the invention as illustrated in the accompanying drawings. It is here noted that the present invention is equally applicable to axisymmetric type exhaust nozzles as to multi-i5 function, two-dLmensional exhaust nozzles hereinbefor- described.
However, for purposes of desoribing the present preferred embodi-- ~ ment of the invention, and not by way of limitation, the descrip-tion below is directed primarily to a hinge incorporating the teachings of the present invention which connects first and second wall sections of a two-dimensional type exhaust nozzle. Further-more, while a plurality of hLnges of the present invention may be incorporated in a given exhaust nozzle to connect the various pivoting wall sections, each hinge would have s~ubstantially the same configuration, thus, only one such hinge is described herein-below. It will be apparent to those skilled in the art that thedescription of the hinge connection f or pivoting wall sections of the two-dLmensional nozzle is equally applicable to connections of _g_ `. ~
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wall sections of an axisymmetric type nozzle and o~her ~ariations on multifunction type exhaust nozzles.
In accordance with the present invention, a hinge means i~
provided for connecting a first wall section and a second wall section of an exhaust nozzle. As embodied herein, and as illus-trated in Figs. 7 and 8, the hinge means includes a hinge generally referred to as 100. Hinge 100 connects a first wall ~ection 102 and a second wall section 104 and allows relative pivoting motion between first wall section 102 and second wall lo section 104. First and second wall sections 102 and 104 each have an inside surface 106 and 108, respectively. Wall sections 102 and 104 further include liners 110 and 112, respectively, spaced from inside surfaces 106 and 108 to define cooling air flow passages 11~ and 116 therebetween.
In accordance with the preqent invention, the hinge comprises a curved portion formed at a first end of one of the first and second wall sections. In the preferred embodiment of the present ~ invention illustrated in Figs. 7 and 8, curved portion 118 is ~; formed at a first end 120 of second wall section 104.
` 20 In accordance with the present invention, the hinge further includes seal means for forming a substantially air tight seal between the curved portion of the second wall section and a firs~
end of the first wall section as the first and second wall sections pivot relative to one another. Preferably, the seal mea~s compr~ses a leaf seal means, fixedly attached to and extending from one of the wall sections, for slidably bearing against the other wall section to form a substantially airtight ~' ~. .. ,. - : :
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seal therebetween as the first and second wall sections pivot relative to one another. As embodied and illustrated in Fig. 7, - the leaf seal means is fixedly attached to a first end 121 of wall ~ection 102 and includes leaf seal 122 having a root portion 124 and a biasing portion 126 cantilevered from root portion 124.
Bia~ing portion 126 includes a distal end portion 128. Root portion 124 of leaf seal 122 is attached ~o first end 121 of wall section 102 via a bracket 130. Root portion 124 is firmly fixed to bracket 130 by a bolted connection 132. Alternatively, root portion 124 may be attached to bracket 130 by welding or any other fastening means. Bracket 130 is in turn fixedly attached to wall section 102 by a bolted connection 134. Bracket 130 is of course not limited to being connected to wall section 102 by bolt 134 and may also be welded to wall section 102 or attached by any other lS known fa~tening means. Alternatively, root portion 124 may be fixedly attached directly to wall section 102. In the present preferred embodiment bracket 130 serves to position and support biasing portion 126 of leaf seal 122 in the desired position as will be discussed hereinafter.
~; 20 With the configuration of leaf seal 122 and bracket 130 as shown in Figs. 7 and 8, the distal end 128 of biasing portion 126 conforms to, and slidably bears against, cur~ed portion 118 of second wall section 104 as wall sections 102 and 104 pivot ~; relatiYe to one another thereby forming an airtight seal between -~ 25 biasing portion 126 and cur~ed portion 118.
In accordance with the present invention, the hinge further ;.: : . ,; includes plenum means, defined at least in part by the leaf seal :~.
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means and a first end of one wall section, for flow communicating the firs~ and second cooling air flow passages. As embodied herein, and as shown in Figs. 7 and 8, the plenum means comprises a plenum 136 defined a~ least in part by first end 121 of wall section 102 and leaf seal 122. Each of wall sections 102 and 104 have a width along respective first ends 120 and 121 thereo~ sub-stantially commensurate with one another. Liners 110 and 11~ also have a width substantially commensurate wi~h the widths of wall sections 102 and 104. Plenum 136 extends along substantially the entire width of first ends 120 and 121 of first and second wall sections 102 and 104, respectively, to form a continuous air flow path between first cooling air flow passage 114 and sesond cooling air flow passage 116 through plenum 136 along substantially the entire width of wall sections 102 and 104. The airflow path of cooling air through the cooling air flow passages and plenum is , .~
illustrated in Fig. 7 with arrows 138. Thus, since plenum 136 connects cooling air flow passages 114 and 116 along substantially the entire width of wall sections 102 and 104, uniform flow of cooling air through the plenum and along the wall sections is obtained without mixing with the hot exhaust gases exiting through the nozzle.
In accordance with the present in~ention, the hinge further includes offset bracket msans for pivotably connecting the first and second wall sections at respective first ends thereof. As embodied herein, the offset bracket means includes at least two brackets 140. With reference to Figs. 9 and 11, bracket 140 includes a base portion 142 and an arm portion 144 extending from ' ' ~ ' . : ~' .. , : -~ .. .. .. :
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base portion 142. ~ase portion 142 is fixedly attached to first end 121 of wall section 102 by welding or by any other suitable fastening means. Each of the at least two brackets 140 are spaced from one another along the width of first end 121 of wall section 102. Arm portion 144 of bracket 140 includes a distal end portion 146 having an aperture 148. Distal end portions 146 of e~ch bracket are thus offse~ by the length of arm portion 144 from wall section 102. In this manner the brackets 140 provide a con-.~ figuration for pivotably connecting the first and second wall sections while stepping over curved end portion 118 as discussed below.
Ribs 1~0 are fixedly attached to wall section 104 proximate first end 120 by welding, for ex~mple. Each pair of ribs 150 are spaced to receive distal end portion 146 of bracket 140 therein and includes apertures 151 which align with aper ure 148 when : distal end portion 146 is received between ribs 150. Wall section 104 is pivota~ly attached to distal end 146 of arm portion 144 by means of pins 152 which extend through aperture 148 of bracket 140 and apertures 151 of ribs 150 to connect wall sections 102 and 104 in an assemhled state.
The configuration of the offset bracket means permits wall sections 102 and 104 to pivot relative to one another to different : angular orientations in accordance with the opera~ing condition of ; : the nozzle while stepping over curved portion 118 of wall section 104. In this manner, curved portion 118 remains spaced ~ ~ from first end 121 of wall s~ction 102 to partially define ::;~ plenum 136. Moreover, while Fi~. 9 illustrates at least two ~: :.
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, ~, brackets 140, each is substantially identical in construction, thus, only one has been described abo~e. Furthermore, any number of brackets 140 may be arranged along the first ends of wall sections 102 and 104 to pivotably connect the wall sections in the S assembled state and securely support the same. The present invention is not limited to the specific configuration of the bracket 140 shown and described and numerous other configurations for the offset bracket means will be envisioned by those skilled in the art while remaining within the scope of the present lnvention.
With reference to Figs. 7 and 8, liner 112 of wall section 104 includes a curved upstream end portion 154 spaced from curved portion 118 of second wall section 104 to thereby define the upstream-most portion of cooling air flow passage 116.
15 Liner 110 includes a downstream end portion 156 terminating proximate to and spaced from curved end portion 154 of liner 11 to define an airflow path 158 therebetween.
Airflow path 158 between curved upstream end por~ion 154 of liner 112 and downstream end portion 156 of liner 110 may be ' 20 dimensioned to control the amount of coolant air leakage from plenum 136 and to eject a thin film of cooling air along the , . .
surface of liner 112 as indicated by arrow 160. Alternatively, hinge 100 may be configured with a means for sealing airflow path 158. As embodied herein, the sealing means may incorporate a . .
leaf spring 162 fixedly attached to downs~ream end portion 156 of `~ ~ liner 110 wherein a leaf 164 of Ieaf spring 162 is configured to . ' .
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13~V-9099 bias against curved upstream end portion 154 of liner 112 to thereby seal airflow gap 158.
Cur~ed portion 118 of wall section 104 includes at leas~ two notched portions 166 illustrated by dotted lines in Fig. 8.
Notched portions 165 are spaced from one another along the width of wall section 112 to correspond to arm portions 144 of brackets 148. Arm portions 144 are movable into and out of notched portions 166 of curved portion 118 as first and second ~ wall sections 102 and 104 pivot relative to one another about ~he ; 10 offset bracket means. When wall sections 102 and 104 are positioned relative to one another such that the exhaust nozzle is in a fully deflected configuration as shown in Fig. 3, curved upstream end portion 154 of liner 112 extends upward into plenum 136 and arm portions 144 move into notched portions 166. In this position the flow path of cooling air through air flow passage 114 is into plenum 136 and then around the end of curved upstream end portion 154 and back down and into cooling air flow passage 116 as again illustrated by arrows 138.
~, With reference to Fig. 9, leaf seals 122 extend along the , ~,, width of wall sections 102 and 104 and are interrupted by brackets 140 spaced across the width of wall sec~ion 102. In this i:
manner leaf seals 122 do not interfere with bracXets 140 as wall sections 102 and 104 pivot relative to one another. To control leakage from plenum 136 through notched portions 166, local 25 appendages 16B are attached to distal end 128 of cantilevered portion 126 of each leaf seal to bridge notch portions 166 and ~, seal plenum 136 as first and second wall sections 102 and 104 ~. ~
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'-` ~ 13DV-9099 pivot about the offset bracket means to progressively larger angles therebetween. In this manner, potential leakage loss o~
cooling air from plenum 136 is minimized by sealing notch i portions 166 with appendages 168 as the wall sections pivot relative to one another and curved end portion 118 of wall section 104 for each of the angular orientations of the wall sections. Similarly, leakage through air gap 158 between down-stream end portion 156 of liner 110 and curved upstream end portion 154 of liner 112 may be minimized by incorporation of leaf spring 162 across gap 158.
A third potential leakage point of cooling air from plenum 136 exists at the endmost connections of wall section 102 and 104 where these endmost connections abut adjoining wall sections. To minimize leakage of cooling air from the dis~al ends of plenum 136, an end cap 170 is attached to each distal edge of the first end 120 of wall section 102, as illustrated in Figs. 9 ; and 10, to seal plenum 136 at the ends thereof. End cap 170 fits closely with the end of leaf seal 122 and bracket 130 to minimize ~ loss of coolant air flow between the mating surfaces thereof. To ; 20 control leakage at the interface of wall sections 102 and 104 and a side wall 172 of the nozzle, a cylindrical seal 174 is inserted in each endmost portion of the curved portion 118 of wall section 104. A spring 176 may be inserted within each cylindrical ; seal 174 to bias against an abutment 177 and urge each cylindrical seal towards a respective side wall 172 of the nozzle. Here again, since the end caps 170 and as~ociated cylindrical seals 174 disposed at each outermost edge of wall sections 102 and 104 are ~; .
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2a2l0~6 substantially identical in construction, only one edge configura-tion is illustrated and described herein.
In the preferred embodlment of the present invention described hereinabove, wall section 104 comprises a diverging flap S of a two-dimensional exhaust nozzle and wall section 102 comprises a converging flap of the exhaust nozzle. The con~erging flap 102 i9 positioned upstream of diverging flap 104 in the exhaust gas flow path through the nozzle. Liners 110 and 112 o~ converging and diverging flaps 102 and 104 define a portion of the gas flow lo path through the nozzle. However, the present invention is not limited to use at the connection between converging and diverging flaps of a two-dimensional nozzle. Alternatively, as illustrated schematically in Fig. 12, the teachings of the present invention may be incorporated at a hinge connection between a nozzle casing lS section and the converging wall section, such as in hinge connection 200 between nozzle casing section 202 and converging wall section 102. A liner 204 is spaced from casing section 202 to define a cooling air flow pa~sage 206 therebetween. In this em~odiment, cooling air flowing through passage 206 arrives in plenum 208 at hinge connection 200 and from plenum 208 passes into cooling air flow passage 114 along substantially the entire width of convergen~ wall section 102 and into plenum 136 of hinge lO0.
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; From plenum 136 cooling air flows into cooling air flow passage l16 of divergen~ wall section 104. Thus the present invention may be incorporated at each pivota~le connection of respective wall sections defining the exhaust nozzle gas flow ~, path.
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-Furthermore, the preferred embodiment of the present invention has been described hereinabove with curved portion 118 formed at first end 120 of wall section 104 and with the leaf seal means fixedly attached to and extending from first end 121 of wall section 102. However it is well within the scope of the present invention that the curved portion be formed at first end 121 of wall section 102 with the leaf seal means and the offset bracket means extending from first end 120 of wall section 104. With such an arrangement the plenum means is still defined at least in part by the leaf seal means and the first end of one of the wall sections, and coolin~ air flow is directed from cooling air flow passage 114 into plenum 136 and therefrom into cooling air flow passage 116.
The present invention provides a novel configuration of an exhaust nozzle hinge capable of transferring cooling air flow from an upstream cooling air flow passage defined by a liner spaced from the upstream wall section, to a downstream cooling air flow passage defined by a liner spaced from the downstream wall section. This arrangement allows for more efficient use of ~; ~o cooling air passing throuqh the cooling air flow passages and is particularly applicable to two-dimensional exhaust nozzles wherein the diverging flaps are of relatively long length. Through use of the pre~ent invention avoidance of thermal distortion and fatigue, and generally improved maintainability of the wall section5 of the exhaust nozzle may be obtained.
- Additional advantages and modifications will readily occur to those skilled in the art. The invention in its broadest aspects ~` :
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is, therefore, not lLmited to the specific details, representative apparatus and illu~trative examples shown and described.
Accordingly, departures may be made from such details without departinq from the spirit or scope of the applicants' inventive S concept.
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Claims (25)
1. A hinge for axially connecting a first wall section and a second wall section of a gas turbine engine exhaust nozzle and for allowing relative pivoting motion therebetween, said first and second wall sections each having an inside surface and a liner attached to and spaced from a respective one of said inside surfaces for defining first and second cooling air flow passages therebetween, comprising:
a curved portion formed at a first end of one of said first and second wall sections;
leaf seal means, fixedly attached to and extending from a first end of the other one of said first and second wall sections, for slidably bearing against said curved portion to form a substantially air-tight seal therebetween as said first and second wall sections pivot relative to one another;
plenum means, defined at least in part by said leaf seal means and said first end of said other one of the first and second wall sections, for flow communicating said first and said second cooling air flow passages; and offset bracket means for pivotably connecting said first and second wall sections at said respective first ends thereof.
a curved portion formed at a first end of one of said first and second wall sections;
leaf seal means, fixedly attached to and extending from a first end of the other one of said first and second wall sections, for slidably bearing against said curved portion to form a substantially air-tight seal therebetween as said first and second wall sections pivot relative to one another;
plenum means, defined at least in part by said leaf seal means and said first end of said other one of the first and second wall sections, for flow communicating said first and said second cooling air flow passages; and offset bracket means for pivotably connecting said first and second wall sections at said respective first ends thereof.
2. The hinge of claim 1 wherein said first and second wall sections comprise a converging flap and a diverging flap, respec-tively, of said exhaust nozzle and said liners spaced from said inside surfaces thereof define a portion of a gas flow path through said nozzle, said converging section being positioned up-stream of said diverging section in said gas flow path.
3. The hinge of claim 1, wherein said first and second wall sections of said nozzle comprise a casing section and a converging flap, respectively, of said exhaust nozzle and said liners spaced from said inside surfaces thereof define a portion of a gas flow path through said nozzle, said casing section being positioned upstream of said diverging section in said gas flow path.
4. The hinge of claim 1, wherein said liners of said first and second wall sections define a portion of a gas flow path through said nozzle, said first wall section being positioned upstream of said second wall section in said gas flow path and said curved portion being formed at the upstream end of said second wall section.
5. The hinge of claim 4, wherein said liner of said second wall section includes a curved upstream end portion spaced from said curved portion of said second wall section to define a portion of the respective cooling air flow passage.
6. The hinge of claim 5, wherein said liner of said first wall section includes a downstream end portion terminating proximate to and spaced from said curved end portion of said liner of said second wall section to define an air flow path therebetween.
7. The hinge of claim 6 including means for sealing said air flow path between the downstream end portion of said liner of said first wall section and the upstream curved portion of said liner of said second wall section.
8. The hinge of claim 1, wherein said offset bracket means includes at least two brackets each having a base portion, fixedly secured to and spaced from one another on said first end of said other one of the first and second wall sections, and an arm portion extending from said base portion and having a distal end thereof, said one of the first and second wall sections being pivotably attached to said distal end of each said arm portion.
9. The hinge of claim 8, wherein said seal means includes at least one leaf seal having a root portion, said root portion being fixedly attached to said other one of the first and second wall sections and extending between said arm portions of said brackets, and a biasing portion cantilevered from a distal end of said root portion, said biasing portion being configured along at least a portion thereof to conform to and slidably bear against said curved portion as said first and second wall sections pivot relative to one another.
10. The hinge of claim 9, wherein said curved portion of said one of the first and second wall sections includes at least two notched portions spaced from one another to correspond to said arm portions of each of said at least two brackets, said arm portions being movable into and out of said notched portions as said first and second wall sections pivot relative to one another about said offset bracket means.
11. The hinge of claim 10, wherein said leaf seal means includes appendages attached to a distal end of said cantilevered portion of said at least one leaf seal to bridge said notch portions of said curved portion and seal said plenum means as said first and second wall sections pivot about said offset bracket means to progressively larger angles therebetween.
12. The hinge of claim 1, wherein said first and second wall sections have a width along respective first ends thereof substan-tially commensurate with one another, and said plenum means and said liners extend along substantially the entire width of said first ends of said first and second wall sections to form a continuous air flow path between said first and second cooling air flow passages along said width, and further including means for sealing said plenum means at the distal ends thereof.
13. The hinge of claim 12, wherein said first and second wall sections comprise convergent and divergent flap sections, respectively, disposed between and adjacent to sidewall sections of a two-dimensional exhaust nozzle, and said means for sealing the distal ends of said plenum means includes:
end caps attached to the distal edges of said first end of said other one of the convergent and divergent flaps to seal said plenum means at the ends thereof;
a pair of cylindrical seals dimensioned to slidably fit within respective endmost portions of said curved portion of said one of the convergent and divergent flaps; and spring means for biasing said pair of cylindrical seals toward said sidewall sections of said nozzle.
end caps attached to the distal edges of said first end of said other one of the convergent and divergent flaps to seal said plenum means at the ends thereof;
a pair of cylindrical seals dimensioned to slidably fit within respective endmost portions of said curved portion of said one of the convergent and divergent flaps; and spring means for biasing said pair of cylindrical seals toward said sidewall sections of said nozzle.
14. A gas turbine engine having a nozzle defining an exhaust gas flow path, comprising:
a plurality of pairs of upstream and downstream nozzle wall sections each having a substantially commensurate width at a first end thereof and an inside surface, and each wall section further including a liner spaced from respective ones of said inside surfaces to define cooling air flow passages therebetween;
hinge means for pivotably connecting respective ones of said pairs of wall sections at respective first ends thereof, said hinge means including:
a curved portion formed at said first end of one of said upstream and downstream wall sections of each said pair;
leaf seal means, fixedly attached to and extending from said first end of the other one of each said pair of upstream and downstream wall sections, for slidably bearing against said curved portion to form a substantially air-tight seal therebetween as said upstream and downstream wall sections pivot relative to one another;
plenum means, defined at least in part by said leaf seal means and said first end of said other of the upstream and downstream wall sections, for flow communicating said first and said second cooling air flow passages; and offset bracket means for pivotably connecting each said pair of upstream and downstream wall sections at said respective first ends thereof.
a plurality of pairs of upstream and downstream nozzle wall sections each having a substantially commensurate width at a first end thereof and an inside surface, and each wall section further including a liner spaced from respective ones of said inside surfaces to define cooling air flow passages therebetween;
hinge means for pivotably connecting respective ones of said pairs of wall sections at respective first ends thereof, said hinge means including:
a curved portion formed at said first end of one of said upstream and downstream wall sections of each said pair;
leaf seal means, fixedly attached to and extending from said first end of the other one of each said pair of upstream and downstream wall sections, for slidably bearing against said curved portion to form a substantially air-tight seal therebetween as said upstream and downstream wall sections pivot relative to one another;
plenum means, defined at least in part by said leaf seal means and said first end of said other of the upstream and downstream wall sections, for flow communicating said first and said second cooling air flow passages; and offset bracket means for pivotably connecting each said pair of upstream and downstream wall sections at said respective first ends thereof.
15. The engine of claim 14, wherein said liner of said one of the upstream and downstream wall sections includes a curved end portion spaced from said curved portion to define a portion of the respective cooling air flow passage.
16. The engine of claim 15, wherein said liner of said other one of the upstream and downstream wall sections includes an end portion terminating proximate to and spaced from said curved end portion of said liner of said one wall section to define an air flow path therebetween.
17. The engine of claim 16 including means for sealing said air flow path between the downstream end portion of said liner of said other one of the upstream and downstream wall sections and the upstream curved portion of said liner of said one of the upstream and downstream wall sections.
18. The engine of claim 14, wherein said offset bracket means includes at least two brackets each having a base portion, fixedly secured to and spaced from one another on said first end of said other one of the upstream and downstream wall sections, and an arm portion extending from said base portion and having a distal end thereof, said one of the upstream and downstream wall sections being pivotably attached to said distal end of each said arm portion.
19. The engine of claim 18, wherein said leaf seal means includes at least one leaf seal having a root portion, said root portion being fixedly attached to said other one of the upstream and downstream wall sections and extending between said arm portions of said brackets, and a biasing portion cantilevered from a distal end of said root portion, said biasing portion being con-figured along at least a portion thereof to conform to and slidably bear against said curved portion as said upstream and downstream wall sections pivot relative to one another.
20. The engine of claim 19, wherein said curved portion of said one of the upstream and downstream wall sections included at least two notched portions spaced from one another to correspond to said arm portions of each of said at least two brackets, said arm portions being movable into and out of said notched portions a said upstream and downstream wall sections pivot relative to one another about said offset bracket means.
21. The engine of claim 20, wherein said leaf seal means includes appendages attached to a distal end of said cantilevered portion of said at least one leaf seal to bridge said notch portions of said curved portion and seal said plenum means as said first and second wall sections pivot about said offset bracket means to progressively larger angles therebetween.
22. The engine of claim 14, wherein said plenum means and said liners extend along substantially the entire width of said first ends of said upstream and downstream wall sections to form a continuous air flow path between said first and second cooling air flow passages along said width, and further including means for sealing said plenum means at the distal ends thereof.
23. The engine of claim 14, including a source of cooling air and means for directing the cooling air into said cooling air flow passage of the upstream wall section.
24. A hinge for axially connecting a first wall section and a second wall section of a gas turbine engine exhaust nozzle and for allowing relative pivoting motion therebetween, said first and second wall sections each having an inside surface and a liner attached to and spaced from a respective one of said inside surfaces for defining first and second cooling air flow passages therebetween, comprising:
a curved portion formed at a first end of one of said first and second wall sections;
seal means for forming a substantially air-tight seal between said curved portion of said one wall section and a first end of the other one of said first and second wall sections as said first and second wall sections pivot relative to one another;
plenum means, defined at least in part by said seal means and said first end of said other one of the first and second wall sections, for flow communicating said first and said second cooling air flow passages; and offset bracket means for pivotably connecting said first and second wall sections at said respective first ends thereof.
a curved portion formed at a first end of one of said first and second wall sections;
seal means for forming a substantially air-tight seal between said curved portion of said one wall section and a first end of the other one of said first and second wall sections as said first and second wall sections pivot relative to one another;
plenum means, defined at least in part by said seal means and said first end of said other one of the first and second wall sections, for flow communicating said first and said second cooling air flow passages; and offset bracket means for pivotably connecting said first and second wall sections at said respective first ends thereof.
25. The invention as defined in any of the preceding claims including any further features of novelty disclosed.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US40402189A | 1989-09-07 | 1989-09-07 | |
| US404,021 | 1989-09-07 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2021086A1 true CA2021086A1 (en) | 1991-03-08 |
Family
ID=23597809
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2021086 Abandoned CA2021086A1 (en) | 1989-09-07 | 1990-07-12 | Exhaust nozzle hinge |
Country Status (5)
| Country | Link |
|---|---|
| JP (1) | JPH0711259B2 (en) |
| CA (1) | CA2021086A1 (en) |
| DE (1) | DE4014574A1 (en) |
| FR (1) | FR2651536A1 (en) |
| GB (1) | GB2235728A (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5255849A (en) * | 1991-11-05 | 1993-10-26 | General Electric Company | Cooling air transfer apparatus for aircraft gas turbine engine exhaust nozzles |
| US5794851A (en) * | 1995-12-07 | 1998-08-18 | United Technologies Corporation | Nozzle sealing apparatus |
| DE19608083A1 (en) * | 1996-03-02 | 1997-09-04 | Mtu Muenchen Gmbh | Seal for two relatively moving machine parts |
| US5813609A (en) * | 1996-12-11 | 1998-09-29 | General Electric Company | Hinged lined exhaust nozzle |
| WO2014185272A1 (en) | 2013-05-15 | 2014-11-20 | 株式会社Ihi | Variable nozzle for aircraft gas turbine engine |
| FR3100286B1 (en) * | 2019-08-30 | 2021-09-17 | Safran Aircraft Engines | TORQUE CONVERGENT-DIVERGENT FLAP FOR VARIABLE GEOMETRY TURBOREACTOR NOZZLE INCLUDING COOLING AIR CIRCULATION DUCTS CONNECTED THROUGH CONTACT SURFACES |
| FR3100282B1 (en) * | 2019-08-30 | 2023-02-10 | Safran Aircraft Engines | CONVERGENT FLAP-DIVERGENT FLAP PAIR FOR VARIABLE GEOMETRY TURBOJET NOZZLE WHOSE FLAPS INCLUDE COOLING AIR CIRCULATION DUCT CONNECTED BY PLUG-IN |
| CN114151197B (en) * | 2021-10-20 | 2022-12-16 | 中国航发四川燃气涡轮研究院 | Cooling drainage structure of thin-wall high-rib round-square casing |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NL87657C (en) * | 1953-04-10 | |||
| GB892289A (en) * | 1958-02-13 | 1962-03-21 | Power Jets Res & Dev Ltd | Duct for conveying fluid flow |
| GB851085A (en) * | 1958-02-27 | 1960-10-12 | Lucas Industries Ltd | Jet discharge nozzles for jet-propulsion engines |
| US3046730A (en) * | 1960-09-21 | 1962-07-31 | Marquardt Corp | Variable area exit nozzle |
| US3979065A (en) * | 1974-10-31 | 1976-09-07 | United Technologies Corporation | Cooling liner for an exhaust nozzle |
| US4073441A (en) * | 1976-10-04 | 1978-02-14 | General Electric Company | Gas turbine engine nozzle apparatus including a nozzle flap slot seal |
| US4081137A (en) * | 1977-01-05 | 1978-03-28 | The United States Of America As Represented By The Secretary Of The Air Force | Finned surface cooled nozzle |
| US4544098A (en) * | 1982-12-27 | 1985-10-01 | United Technologies Corporation | Cooled exhaust nozzle flaps |
| US4742961A (en) * | 1987-05-04 | 1988-05-10 | United Technologies Corporation | Exhaust gas nozzle including a cooling air diverter |
-
1990
- 1990-05-01 JP JP11191490A patent/JPH0711259B2/en not_active Expired - Lifetime
- 1990-05-03 FR FR9005584A patent/FR2651536A1/en active Pending
- 1990-05-04 GB GB9010081A patent/GB2235728A/en not_active Withdrawn
- 1990-05-07 DE DE19904014574 patent/DE4014574A1/en not_active Withdrawn
- 1990-07-12 CA CA 2021086 patent/CA2021086A1/en not_active Abandoned
Also Published As
| Publication number | Publication date |
|---|---|
| DE4014574A1 (en) | 1991-03-21 |
| JPH0711259B2 (en) | 1995-02-08 |
| GB2235728A (en) | 1991-03-13 |
| FR2651536A1 (en) | 1991-03-08 |
| JPH03100359A (en) | 1991-04-25 |
| GB9010081D0 (en) | 1990-06-27 |
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Legal Events
| Date | Code | Title | Description |
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| FZDE | Dead |