Patent Publication Number: US-2023160355-A1

Title: Mixed flow exhaust thrust reverser with area control nozzle systems and methods

Description:
FIELD 
     The present disclosure relates generally to aircraft nozzles and thrust reversers used with gas turbine engines and, more particularly, to mixed flow exhaust nozzles incorporating thrust reversers. 
     BACKGROUND 
     Turbofan gas turbine engines are known to include a fan section that produces a bypass airflow for providing the majority of engine propulsion and a core engine section through which a core airflow is compressed, mixed with fuel, combusted and expanded through a turbine to drive the fan section. In a mixed flow turbofan engine, the cool bypass airflow is ducted between a surrounding nacelle and an outer casing of the core engine section and mixed with a hot exhaust stream from the core engine section prior to discharge from the engine nozzle in a combined or mixed exhaust stream. The surrounding nacelle may include a thrust reverser capable of redirecting the mixed exhaust stream from a rearward direction to, at least partially, a forward direction thus producing a rearward thrust that may serve to decelerate forward motion of an aircraft and thereby assist braking the aircraft upon landing. 
     SUMMARY 
     An exhaust nozzle for an aircraft engine nacelle is disclosed, comprising a forward bulkhead, an outer articulating panel comprising an outer skin and an outer thrust reverser door, the outer articulating panel is configured to pivot with respect to the forward bulkhead, an inner articulating panel comprising a forward inner skin, an aft inner skin, and an inner thrust reverser door, the inner articulating panel configured to pivot with respect to the forward bulkhead, a nozzle throat at least partially defined at an interface between the forward inner skin and the aft inner skin, a nozzle exit at least partially defined at an aft end of the inner articulating panel, a first nozzle actuator configured to vary an angle of the outer articulating panel with respect to the forward bulkhead, and a second nozzle actuator configured to vary an angle of the forward inner skin with respect to the forward bulkhead. A nozzle throat area of the nozzle throat is configured to be varied by the second nozzle actuator independent of a nozzle exit area of the nozzle exit. The nozzle exit area is configured to be varied by the first nozzle actuator independent of the nozzle throat area. 
     In various embodiments, the exhaust nozzle further comprises a flap pivotally coupled to the forward bulkhead, wherein the outer skin is slidingly coupled to the flap, and the outer skin translates with respect to the flap in response to the angle of the outer articulating panel varying with respect to the forward bulkhead to maintain a continuous aerodynamic outer surface of the exhaust nozzle. 
     In various embodiments, the outer skin is configured to pivot with respect to the forward bulkhead independent of the forward inner skin. 
     In various embodiments, the exhaust nozzle further comprises a first thrust reverser actuator configured to move the outer thrust reverser door between a stowed position and a deployed position. 
     In various embodiments, the exhaust nozzle further comprises a second thrust reverser actuator configured to move the inner thrust reverser door between a stowed position and a deployed position. 
     In various embodiments, the first nozzle actuator and the second nozzle actuator are configured to operate in concert to vary either the nozzle throat area or the nozzle exit area and either maintain or vary the other of the nozzle throat area and the nozzle exit area. 
     In various embodiments, the nozzle exit area comprises a substantially rectangular geometry. 
     In various embodiments, the exhaust nozzle further comprises a sliding joint offset from the interface between the forward inner skin and the aft inner skin, wherein the forward inner skin and the aft inner skin are coupled together at the sliding joint. 
     In various embodiments, the exhaust nozzle further comprises a linear joint coupled between the first nozzle actuator and the outer articulating panel, the linear joint configured to transmit lateral loads between the forward bulkhead and the outer articulating panel. 
     A thrust reverser is disclosed, comprising an outer articulating panel and an inner articulating panel. The outer articulating panel comprises an outer skin and an outer thrust reverser door. The outer articulating panel is configured to pivot to vary a nozzle exit area. The inner articulating panel comprises a forward inner skin, an aft inner skin, and an inner thrust reverser door. The forward inner skin is configured to pivot to vary a nozzle throat area. The outer thrust reverser door is pivotally coupled to the outer skin, and the inner thrust reverser door is pivotally coupled to the aft inner skin. 
     In various embodiments, a nozzle throat is at least partially defined at an interface between the forward inner skin and the aft inner skin. 
     In various embodiments, a nozzle exit is at least partially defined at an aft end of the inner articulating panel. 
     In various embodiments, the thrust reverser further comprises a first thrust reverser actuator configured to pivot the outer thrust reverser door with respect to the outer skin between a deployed position and a stowed position. 
     In various embodiments, the thrust reverser further comprises a second thrust reverser actuator configured to pivot the inner thrust reverser door with respect to the aft inner skin between a deployed position and a stowed position. 
     In various embodiments, the thrust reverser further comprises a first nozzle actuator configured to pivot the outer articulating panel. 
     In various embodiments, the thrust reverser further comprises a second nozzle actuator configured to pivot the forward inner skin. 
     In various embodiments, the thrust reverser further comprises a first linear joint disposed between the first nozzle actuator and the outer articulating panel, and a second linear joint disposed between the second nozzle actuator and the forward inner skin. 
     In various embodiments, the thrust reverser further comprises a third linear joint disposed between the first thrust reverser actuator and the outer thrust reverser door, and a fourth linear joint disposed between the second thrust reverser actuator and the inner thrust reverser door. 
     In various embodiments, the thrust reverser further comprises a flap located at a forward edge of the outer skin, wherein the flap is slidingly coupled to the outer skin to maintain a continuous aerodynamic surface while the outer articulating panel pivots. 
     A method for articulating an exhaust nozzle to vary at least one of a nozzle throat area and a nozzle exit area is disclosed, the method comprising moving a first nozzle actuator to vary an angle of an outer articulating panel of the exhaust nozzle with respect to a forward bulkhead and to either maintain or vary the nozzle exit area, moving a second nozzle actuator to vary an angle of an inner articulating panel of the exhaust nozzle with respect to the forward bulkhead, and varying an angle between a forward inner skin of the inner articulating panel and an aft inner skin of the inner articulating panel in response to performing the step of moving the second nozzle actuator to either maintain or vary the nozzle throat area. 
     In various embodiments, the method further comprises moving a first thrust reverser actuator to pivot an outer thrust reverser door between a stowed position and a deployed position, wherein the outer thrust reverser door is pivotally mounted to an outer skin of the outer articulating panel, and moving a second thrust reverser actuator to pivot an inner thrust reverser door between a stowed position and a deployed position, wherein the inner thrust reverser door is pivotally mounted to an aft inner skin of the inner articulating panel. 
     The foregoing features and elements may be combined in various combinations without exclusivity, unless expressly indicated herein otherwise. These features and elements as well as the operation of the disclosed embodiments will become more apparent in light of the following description and accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The subject matter of the present disclosure is particularly pointed out and distinctly claimed in the concluding portion of the specification. A more complete understanding of the present disclosure, however, may best be obtained by referring to the following detailed description and claims in connection with the following drawings. While the drawings illustrate various embodiments employing the principles described herein, the drawings do not limit the scope of the claims. 
         FIG.  1 A  provides a schematic view of a gas turbine engine including a nozzle arrangement, in accordance with various embodiments; 
         FIG.  1 B  provides a cross-section view of the nozzle arrangement of  FIG.  1 A , in accordance with various embodiments; 
         FIG.  2    provides a partial section, perspective rear view of a nozzle and thrust reverser, in accordance with various embodiments; 
         FIG.  3    provides a schematic, profile view of four quadrants of a thrust reverser, in accordance with various embodiments; 
         FIG.  4 A  provides a section view of an upper quadrant of a thrust reverser, in accordance with various embodiments; 
         FIG.  4 B  provides a section view of the upper quadrant of the thrust reverser of  FIG.  4 A  with the actuators omitted, in accordance with various embodiments; 
         FIG.  5 A  provides a perspective section view of the upper quadrant of the thrust reverser of  FIG.  4 A  in a first position, in accordance with various embodiments; 
         FIG.  5 B  provides a perspective section view of the upper quadrant of the thrust reverser of  FIG.  5 A  in a second position, in accordance with various embodiments; 
         FIG.  5 C  provides a perspective section view of the upper quadrant of the thrust reverser of  FIG.  5 A  in a third position, in accordance with various embodiments; 
         FIG.  5 D  provides a perspective section view of the upper quadrant of the thrust reverser of  FIG.  5 A  in a fourth position, in accordance with various embodiments; 
         FIG.  5 E  provides a perspective section view of the upper quadrant of the thrust reverser of  FIG.  5 A  with the thrust reverser doors in deployed positions, in accordance with various embodiments; and 
         FIG.  6    provides a perspective view of a translating link for use with an actuator of the thrust reverser arrangement, in accordance with various embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     The following detailed description of various embodiments herein makes reference to the accompanying drawings, which show various embodiments by way of illustration. While these various embodiments are described in sufficient detail to enable those skilled in the art to practice the disclosure, it should be understood that other embodiments may be realized and that changes may be made without departing from the scope of the disclosure. Thus, the detailed description herein is presented for purposes of illustration only and not of limitation. Furthermore, any reference to singular includes plural embodiments, and any reference to more than one component or step may include a singular embodiment or step. Also, any reference to attached, fixed, connected, or the like may include permanent, removable, temporary, partial, full or any other possible attachment option. Additionally, any reference to without contact (or similar phrases) may also include reduced contact or minimal contact. It should also be understood that unless specifically stated otherwise, references to “a,” “an” or “the” may include one or more than one and that reference to an item in the singular may also include the item in the plural. Further, all ranges may include upper and lower values and all ranges and ratio limits disclosed herein may be combined. 
     An articulating exhaust nozzle for a mixed flow (i.e., fan duct and core) nacelle of the present disclosure incorporates features for independently controlling the nozzle throat (A8) and nozzle exit (A9). An articulating exhaust nozzle of the present disclosure further incorporates a thrust reverser (also referred to as a “clamshell” type thrust reverser). An articulating exhaust nozzle of the present disclosure may be suitable for high Mach number aircraft applications. An articulating exhaust nozzle of the present disclosure may be suitable for a rectangular exhaust duct. 
     Referring now to the drawings,  FIG.  1 A  schematically illustrates a gas turbine engine  100  of a mixed flow exhaust turbofan variety. The gas turbine engine  100  generally includes a fan section  102  and a core engine section  104 , which includes a compressor section  106 , a combustor section  108  and a turbine section  110 . The fan section  102  drives air along a bypass flow path B in a bypass duct  112  defined within a radially inner surface  115  of a nacelle  114  and an outer casing  116  of the core engine section  104 , while the compressor section  106  drives air along a core flow path C of the core engine section  104  for compression and communication into the combustor section  108  and then expansion through the turbine section  110 . 
     The core engine section  104  may generally include a low speed spool and a high speed spool mounted for rotation about a central longitudinal axis A. The low speed spool generally includes an inner shaft that interconnects a fan  118  within the fan section  102 , a low pressure compressor within the compressor section  106  and a low pressure turbine within the turbine section  110 . The inner shaft may be connected to the fan  118  through a speed change mechanism or gear box to drive the fan  118  at a lower rotational speed than the rotational speed of the low speed spool. The high speed spool generally includes an outer shaft that interconnects a high pressure compressor within the compressor section  106  and a high pressure turbine within the turbine section  110 . A combustor is arranged in the combustor section  108  between the high pressure compressor and the high pressure turbine. The air passing through the bypass flow path B mixes with the combustion gases exiting the core flow path C in a mixing section  122  positioned downstream of the core engine section  104  prior to discharge as a mixed exhaust stream  120 , which provides the thrust achieved by the gas turbine engine  100 . 
     A thrust reverser  130  (also referred to herein as an exhaust nozzle) is mounted to the aft end of the gas turbine engine  100 . The thrust reverser  130  includes an exhaust duct  132 , which defines an outer boundary for discharging the mixed exhaust stream  120  when the thrust reverser  130  assumes a stowed position (also referred to as a closed position or a retracted position), as illustrated in  FIG.  1 A . In various embodiments, exhaust duct  132  defines a substantially rectangular outer boundary for discharging the mixed exhaust stream  120  when the thrust reverser  130  assumes the stowed position. 
     As discussed below, thrust reversal is affected by opening reverser doors to direct all or a portion of the mixed exhaust stream  120  in a direction having an upstream component relative to the central longitudinal axis A of the gas turbine engine  100 . The momentum of the upstream component of the mixed exhaust stream  120  exiting the thrust reverser  130  while in an open or deployed position provides the reverse thrust used to decelerate an aircraft upon landing or during a rejected takeoff. 
     Referring now to  FIG.  1 B , a cross-section view of thrust reverser  130  is illustrated, in accordance with various embodiments. Thrust reverser  130  may comprise an outer articulating panel and a lower articulating panel, as described herein in further detail, each having articulating components that can move to independently vary a throat area A8 and a nozzle exit area A9. In this manner, a thrust reverser of the present disclosure is capable of varying the nozzle throat area A8 independent of the nozzle exit area A9. 
     Referring now to  FIG.  2   , a perspective view of a section of thrust reverser  130  in a stowed position is illustrated, in accordance with various embodiments. It should be appreciated that for ease of illustration, only an upper portion of the thrust reverser  130  is illustrated, and that a lower portion will also be provided, similar to that of the upper section (e.g., in a mirror configuration; see  FIG.  1 B ). Moreover, it should be appreciated that for ease of illustration,  FIG.  4 A  through  FIG.  5 E  illustrate only a half of the upper portion of the thrust reverser  130 , and that the other half will also be provided (e.g., in a mirror configuration). Stated differently, with momentary reference to  FIG.  3   , the illustrated embodiments of  FIG.  4 A  through  FIG.  5 E  depict the details of only a quadrant  301  of the thrust reverser  130 . Quadrant  302  may generally be a mirror image of quadrant  301 . 
     Likewise, quadrants  303  and  304  may generally be mirror images of quadrants  302  and  301 , respectively (see  FIG.  1 B ). Exhaust duct  132  may define a substantially rectangular geometry.  FIG.  2    illustrates a perspective view of the details of quadrants  301  and  302  of thrust reverser  130 , with one sidewall (i.e., the left sidewall in  FIG.  2   ) removed for ease of illustration. 
     With reference to  FIG.  2   , thrust reverser  130  includes a forward bulkhead  202 . Thrust reverser  130  further includes an exhaust nozzle door  204  (also referred to herein as a first articulating exhaust nozzle door). It should be understood that although  FIG.  2    illustrates only the first (top) articulating exhaust nozzle door, the thrust reverser  130  further includes a second (bottom) articulating exhaust nozzle door, similar to that of the first articulating exhaust nozzle door, and in mirror configuration (see  FIG.  1 B ). The bottom exhaust nozzle door is omitted for ease of illustration. 
     Exhaust nozzle door  204  may comprise an outer articulating panel  210  comprising an outer skin  212  and an outer thrust reverser door  214 . The outer articulating panel  210  may be configured to pivot with respect to the forward bulkhead  202 . Outer articulating panel  210  may comprise a width substantially equal to the width  290  of the thrust reverser  130  exhaust outlet. Thrust reverser door  214  may be mounted to outer skin  212 . Thrust reverser door  214  may be configured to pivot with respect to outer skin  212 . 
     Exhaust nozzle door  204  may further comprise an inner articulating panel  220  comprising a forward inner skin  222 , an aft inner skin  224 , and an inner thrust reverser door  226 . Inner articulating panel  220  may be configured to pivot with respect to the forward bulkhead  202 . Inner articulating panel  220  may be configured to pivot with respect to the forward bulkhead  202  independent of outer articulating panel  210 . 
     More particularly, outer skin  212  may be configured to pivot with respect to forward bulkhead  202  independent of forward inner skin  222 . Likewise, forward inner skin  222  may be configured to pivot with respect to forward bulkhead  202  independent of outer skin  212 . 
     Inner articulating panel  220  may comprise a width substantially equal to the width  290  of the thrust reverser  130  exhaust outlet. Inner thrust reverser door  226  may be mounted to aft inner skin  224 . Inner thrust reverser door  226  may be configured to pivot with respect to aft inner skin  224 . 
     In various embodiments, forward inner skin  222 , aft inner skin  224 , and/or inner thrust reverser door  226  may be acoustically treated (e.g., with a honeycomb core or other suitable core) to reduce the overall acoustic signature of thrust reverser  130 . 
     The forward end of inner articulating panel  220  may be disposed radially from the forward end of outer articulating panel  210 . The aft end of inner articulating panel  220  may be located at the aft end of outer articulating panel  210 . In various embodiments, the aft end of inner articulating panel  220  is connected to the aft end of outer articulating panel  210 . In this manner, inner articulating panel  220  and outer articulating panel  210  may form a wedge shape, in accordance with various embodiments. The nozzle exit may be at least partially defined at the aft end of the inner articulating panel  220 . 
     Referring now to  FIG.  4 A , thrust reverser  130  may further include a first nozzle actuator  230  configured to vary an angle of the outer articulating panel  210  with respect to the forward bulkhead  202 . First nozzle actuator  230  may be a linear actuator. 
     The nozzle exit area (e.g., see nozzle exit area A9 of  FIG.  1 B ) is configured to be varied by the first nozzle actuator  230  and second nozzle actuator  232  independent of the nozzle throat area (e.g., see nozzle throat area A8 of  FIG.  1 B ). For example, first nozzle actuator  230  may retract to pivot outer articulating panel  210  inward to reduce the nozzle exit area. Conversely, first nozzle actuator  230  may extend to pivot outer articulating panel  210  outward to increase the nozzle exit area. In both cases, the second nozzle actuator  232  may extend or retract to maintain or change the throat area A8 simultaneously with the movement of first nozzle actuator  230 . 
     Thrust reverser  130  may further include a second nozzle actuator  232  configured to vary an angle of the forward inner skin  222  with respect to the forward bulkhead  202 . Second nozzle actuator  232  may be a linear actuator. A nozzle throat area (e.g., see throat area A8 of  FIG.  1 B ) of the nozzle throat is configured to be varied by the second nozzle actuator  232  independent of a nozzle exit area (e.g., see nozzle exit area A9 of  FIG.  1 B ) of the nozzle exit. The nozzle throat may be at least partially defined at the interface of forward inner skin  222  and aft inner skin  224 . The angle between forward inner skin  222  and aft inner skin  224  may vary in response to second nozzle actuator  232  pivoting forward inner skin  222  with respect to forward bulkhead  202 . For example, second nozzle actuator  232  may extend to pivot forward inner skin  222  inward to reduce the nozzle throat area. Conversely, second nozzle actuator  232  may retract to pivot forward inner skin  222  outward to increase the nozzle throat area. The aft end of forward inner skin  222  and the forward end of aft inner skin  224  may be pivotally connected to each other. 
     Thrust reverser  130  may further include a first thrust reverser actuator  234  configured to move the outer thrust reverser door  214  between a stowed position (see  FIG.  4 A  and  FIG.  5 A ) and a deployed position (see  FIG.  5 E ). First thrust reverser actuator  234  may be a linear actuator. First thrust reverser actuator  234  may be configured to actuate outer thrust reverser door  214  to pivot with respect to outer skin  212  independent of the position of outer skin  212 . 
     Thrust reverser  130  may further include a second thrust reverser actuator  236  configured to move the inner thrust reverser door  226  between a stowed position (see  FIG.  4 A  and  FIG.  5 A ) and a deployed position (see  FIG.  5 E ). Second thrust reverser actuator  236  may be a linear actuator. Second thrust reverser actuator  236  may be configured to actuate inner thrust reverser door  226  to pivot with respect to aft inner skin  224  independent of the position of aft inner skin  224 . In this regard, first nozzle actuator  230 , second nozzle actuator  232 , first thrust reverser actuator  234 , and second thrust reverser actuator  236  may each be independently and individually operated to independently control one or more of nozzle throat area A8 (see  FIG.  1 B ), nozzle exit area A9 (see  FIG.  1 B ), and/or thrust reversal. 
     Thrust reverser  130  may further include a flap  216  between outer skin  212  and forward bulkhead  202 . Flap  216  may be pivotally coupled to forward bulkhead  202 . Flap  216  may be slidingly coupled to outer skin  212  to provide a continuous aerodynamic surface between outer skin  212  and forward bulkhead  202  (and/or the nacelle skin located thereon). Flap  216  may provide a sliding connection between flap  216  and outer skin  212  to maintain said continuous, aerodynamic surface as outer skin  212  pivots between various angular positions with respect to forward bulkhead  202 . 
     Stated differently, flap  216  may form an articulating bridge between outer skin  212  and forward bulkhead  202  to maintain a smooth aerodynamic surface therebetween. Outer skin  212  may translate with respect to flap  216  in response to the angle of the outer skin  212  varying with respect to the forward bulkhead  202  to maintain said continuous aerodynamic outer surface of the exhaust nozzle  130 . 
     Thrust reverser  130  may further include a sliding joint  228  radially offset from the interface  250  between the forward inner skin  222  and the aft inner skin  224 . The forward inner skin  222  and the aft inner skin  224  may be coupled together at the sliding joint  228 . With reference to  FIG.  4 B , thrust reverser  130  is illustrated with the actuators omitted for clarity purposes. Sliding joint  228  may include a first attachment bracket  252  extending from forward inner skin  222  and a second attachment bracket  254  extending from aft inner skin  224 . First attachment bracket  252  may include a track  253  and second attachment bracket  254  may include a pin  255  configured to ride within track  253 . In this manner, the angular rotation of forward inner skin  222  with respect to aft inner skin  224  is supported and guided by sliding joint  228 . It is further contemplated herein that other types of hinges may be used at the interface  250  between forward inner skin  222  and aft inner skin  224 , such as a piano hinge for example. Moreover, the aft ends of aft inner skin  224  and outer skin  212  may be pivotally coupled together with a hinge, such as a piano hinge or any other suitable hinge. Likewise, the forward ends of flap  216  and/or forward inner skin  222  may be pivotally coupled to bulkhead  202  with a hinge of a suitable type. 
     Each nozzle actuator (i.e., first nozzle actuator  230  and second nozzle actuator  232 ) may be coupled to its respective panel or skin via a linear joint (i.e., linear joints  260 ). Each linear joint  260  may be configured to transmit lateral loads between the forward bulkhead  202  and the respective panel or skin. Linear joint  260  may comprise a housing fixed with respect to forward bulkhead  202  and a translating link configured to reciprocally translate along a single axis in response to the associated actuator extending and/or retracting. In this manner, the respective nozzle actuator may experience only longitudinal loads, which may tend to extend the life of the actuator and/or maximize efficiency of the actuator. Each thrust reverser actuator (i.e., first thrust reverser actuator  234  and second thrust reverser actuator  236 ) may similarly be coupled to its respective thrust reverser door via a linear joint (i.e., linear joints  262 ). 
     Referring now to  FIG.  5 A  through  FIG.  5 E , a kinematic model illustrating articulating exhaust nozzle door  204  in various positions is provided with the actuators omitted for ease of illustration. Thrust reverser  130  may guide mixed flow exhaust gasses comprising both air passing through the bypass flow path B and combustion gases exiting the core flow path C. The positions shown in  FIG.  5 A  through  FIG.  5 D  represent discrete nozzle positions during the mission of an aircraft. It should be understood that the present disclosure allows for intermediary nozzle positions within the limits expressed herein. 
     With reference to  FIG.  5 A , articulating exhaust nozzle door  204  is illustrated in a first position with the forward inner skin  222  substantially in parallel with the aft inner skin  224 . In various embodiments, articulating exhaust nozzle door  204  may be in the first position during takeoff. 
     With reference to  FIG.  5 B , articulating exhaust nozzle door  204  is illustrated in a second position with the forward inner skin  222  substantially in parallel with the aft inner skin  224  and the articulating exhaust nozzle door  204  pivoted inward with respect to the first position. In various embodiments, articulating exhaust nozzle door  204  may be in the second position during takeoff at an elevated altitude with respect to the first position. First nozzle actuator  230  and second nozzle actuator  232  may be activated in concert (i.e., simultaneously) to move articulating exhaust nozzle door  204  from the first position to the second position. First nozzle actuator  230  and second nozzle actuator  232  may extend to move the articulating exhaust nozzle door  204  from the first position to the second position to reduce the nozzle exit area. More particularly, first nozzle actuator  230  may be powered to extend to pivot outer skin  212  inward and second nozzle actuator  232  may be powered to extend to pivot forward inner skin  222  and aft inner skin  224  inward. In various embodiments, outer skin  212 , forward inner skin  222 , and aft inner skin  224  may pivot inward together from the first position to the second position. Stated differently, outer articulating panel  210  may be configured to pivot with respect to forward bulkhead  202  to vary the nozzle exit area. 
     With reference to  FIG.  5 C , articulating exhaust nozzle door  204  is illustrated in a third position with the forward inner skin  222  at an angle with the aft inner skin  224  and the forward inner skin  222  pivoted inward with respect to the second position. In various embodiments, articulating exhaust nozzle door  204  may be in the third position during a climb condition. In this regard, in the third position, nozzle throat area is reduced while the nozzle exit area remains substantially the same with respect to the second position. 
     First nozzle actuator  230  and second nozzle actuator  232  may both operate in concert with one another (i.e., simultaneously) to move the articulating exhaust nozzle door  204  from the second position to the third position. First nozzle actuator  230  may retract and second nozzle actuator  232  may extend to move the articulating exhaust nozzle door  204  from the second position to the third position. Outer skin  212  may remain substantially in the same orientation as the second position when the articulating exhaust nozzle door  204  moves to the third position, except that first nozzle actuator  230  may retract slightly to accommodate for the change in total length (i.e., the linear distance between forward bulkhead  202  and the aft tip of aft inner skin  224 ) of the inner articulating panel  220  and to maintain the nozzle exit area. In this manner, outer skin  212  may translate forward with respect to flap  216  when articulating exhaust nozzle door  204  moves from the second position to the third position. 
     With reference to  FIG.  5 D , articulating exhaust nozzle door  204  is illustrated in a fourth position with the forward inner skin  222  at an angle with respect to the aft inner skin  224  and the aft inner skin  224  and outer skin  212  pivoted outward with respect to the third position. In various embodiments, articulating exhaust nozzle door  204  may be in the fourth position during a cruise condition. In this regard, in the fourth position, nozzle exit area is increased while the nozzle throat area remains substantially the same with respect to the third position. First nozzle actuator  230  may retract while second nozzle actuator  232  remains in place to move the articulating exhaust nozzle door  204  from the third position to the fourth position. In this regard, outer skin  212  may be pivoted outward to increase the nozzle exit area. 
     The trailing edge of aft inner skin  224  may pivot about interface  250  with outer skin  212 , while forward inner skin  222  remains stationary with respect to forward bulkhead  202 . Stated differently, outer skin  212  may be configured to pivot with respect to the forward bulkhead  202  independent of the forward inner skin  222 . In this regard, outer articulating panel  210  may be configured to pivot with respect to forward bulkhead  202  to vary the nozzle exit area. 
     With reference to  FIG.  5 E , articulating exhaust nozzle door  204  is illustrated in the first position with the first thrust reverser door  214  and the second thrust reverser door  226  in the deployed positions. In various embodiments, first thrust reverser door  214  and second thrust reverser door  226  may be in the deployed positions during a landing event. In this manner, exhaust gasses are redirected from flowing in an aft direction to a forward direction to generate reverse thrust to an aircraft. First thrust reverser actuator  234  and second thrust reverser actuator  236  may extend to move the first thrust reverser door  214  and second thrust reverser door  226  from the stowed position to the deployed position. 
     With reference to  FIG.  6   , a sliding joint link  400  is illustrated, in accordance with various embodiments. Link  400  may be the translating link of linear joint  260  (see  FIG.  4 B ). Link  400  may comprise a rod  402  having a substantially “I”-shaped cross-section and may terminate at both ends with connection features  404 . The connection features  404  may include apertures for forming a pivoting joint to couple to links (e.g., see links  264 ,  265 ,  266 ,  267 ) pivotally coupled to the associated panels or skins. 
     Finally, it should be understood that any of the above described concepts can be used alone or in combination with any or all of the other above described concepts. Although various embodiments have been disclosed and described, one of ordinary skill in this art would recognize that certain modifications would come within the scope of this disclosure. Accordingly, the description is not intended to be exhaustive or to limit the principles described or illustrated herein to any precise form. Many modifications and variations are possible in light of the above teaching. 
     Benefits, other advantages, and solutions to problems have been described herein with regard to specific embodiments. Furthermore, the connecting lines shown in the various figures contained herein are intended to represent exemplary functional relationships and/or physical couplings between the various elements. It should be noted that many alternative or additional functional relationships or physical connections may be present in a practical system. However, the benefits, advantages, solutions to problems, and any elements that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as critical, required, or essential features or elements of the disclosure. The scope of the disclosure is accordingly to be limited by nothing other than the appended claims, in which reference to an element in the singular is not intended to mean “one and only one” unless explicitly so stated, but rather “one or more.” Moreover, where a phrase similar to “at least one of A, B, or C” is used in the claims, it is intended that the phrase be interpreted to mean that A alone may be present in an embodiment, B alone may be present in an embodiment, C alone may be present in an embodiment, or that any combination of the elements A, B and C may be present in a single embodiment; for example, A and B, A and C, B and C, or A and B and C. 
     Different cross-hatching is used throughout the figures to denote different parts but not necessarily to denote the same or different materials. 
     Systems, methods and apparatus are provided herein. In the detailed description herein, references to “one embodiment”, “an embodiment”, “various embodiments”, etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described. After reading the description, it will be apparent to one skilled in the relevant art(s) how to implement the disclosure in alternative embodiments. 
     Furthermore, no element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims. No claim element herein is intended to invoke 35 U.S.C. 112(f) unless the element is expressly recited using the phrase “means for.” As used herein, the terms “comprises”, “comprising”, or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.