Nozzle assembly for use with propulsion system

Abstract

A nozzle assembly (100, 108, 40, 60, 68) includes a sleeve (106, 108, 44, 66, 68) defining a path (52), the sleeve (106, 108, 44, 66, 68) being disposed within a nacelle (102, 104, 36, 62, 64). The inner surfaces of the path (52) and the nacelle (102, 104, 36, 62, 64) direct the mass flow from the engine (38) to the outlet (102, 42, 62) of the propulsion system. The sleeve (106, 108, 44, 66, 68) is configured to move between a forward position and a rearward position within a nacelle (102, 104, 36, 62, 64) rearward of the engine (38). The sleeve (106, 108, 44, 66, 68) has a protruding portion extending toward the center of the path (52) and defining a minimum inner diameter of the sleeve (106, 108, 44, 66, 68). The sleeve (106, 108, 44, 66, 68) includes a plurality of sleeve segments (68), the sleeve segments (68) being longitudinally aligned and circumferentially arranged to form the sleeve (106, 108, 44, 66, 68). The sleeve section (68) is configured to move circumferentially closer when the sleeve (106, 108, 44, 66, 68) is moved in a first direction within the nacelle (102, 104, 36, 62, 64), and to move circumferentially farther when the sleeve (106, 108, 44, 66, 68) is moved in a second direction within the nacelle (102, 104, 36, 62, 64). An actuator (130, 46) is coupled with the sleeve (106, 108, 44, 66, 68) and is configured to move the sleeve (106, 108, 44, 66, 68).

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 363,823, filed on April 29, 2022, which is hereby incorporated by reference in its entirety. Technical Field

[0003] The present invention relates generally to propulsion systems and, more particularly, to nozzle assemblies for use with aircraft propulsion systems. Background Art

[0004] A supersonic vehicle needs to operate in three different flight regimes. It must operate subsonically, accelerating from a standstill to takeoff and then climbing. Then it must operate transonically, accelerating to and just past the local speed of sound. Finally, it must operate supersonically, accelerating from just above the local speed of sound to its supersonic cruise speed.

[0005] For each flight regime, there is a corresponding desired or optimal nozzle configuration that results in the highest or relatively highest achievable nozzle efficiency. During the first flight regime (takeoff and climb), the highest level of nozzle efficiency is achieved when the nozzle has a converging configuration such that the nozzle throat is juxtaposed with the nozzle exit plane. During the second flight regime (transonic phase), the highest level of nozzle efficiency is achieved when the nozzle has a relatively small converging / diverging configuration (i.e., where the ratio of the exit plane cross-sectional area to the nozzle throat cross-sectional area is slightly greater than 1). Finally, during the third flight regime (supersonic phase), the highest level of nozzle efficiency is achieved when the nozzle has a relatively large converging / diverging configuration (i.e., where the ratio of the exit plane cross-sectional area to the nozzle throat cross-sectional area is substantially greater than 1).

[0006] It is desirable that the nozzle be operated at peak efficiency in all flight regimes. Deviating downward from peak efficiency will adversely affect the specific fuel consumption (SFC) of the propulsion system, which in turn will reduce the range that the aircraft can travel on a given amount of fuel. When any of the three nozzle configurations described above is employed during any flight regime and that nozzle configuration provides less than peak efficiency in that flight regime (e.g., operating the nozzle in a converging configuration during a supersonic phase of flight), it will result in an undesirable reduction in aircraft range or thrust.

[0007] Therefore, it is desirable to provide a nozzle assembly with a variable geometry to provide a relatively high or peak nozzle efficiency in each flight state as the aircraft transitions from one flight state to another. Moreover, other desirable features and characteristics will become apparent from the following summary and detailed description considered in conjunction with the accompanying drawings and the foregoing technical field and background. Summary of the invention

[0008] Various non-limiting embodiments of a nozzle assembly for a propulsion system are disclosed herein.The propulsion system includes an engine configured to generate a mass flow.

[0009] In a first non-limiting embodiment, a nozzle assembly includes but is not limited to a nacelle. The nozzle assembly further includes but is not limited to a sleeve mounted in the nacelle downstream of the engine. The sleeve is configured to move between a forward position and a rearward position in the nacelle, and is further configured to receive a mass flow from the engine and guide the mass flow to an outlet of a propulsion system. The sleeve is composed of a plurality of sleeve segments. Each sleeve segment of the plurality of sleeve segments is longitudinally aligned and arranged in a circumferential arrangement to form a sleeve. The nozzle assembly further includes but is not limited to a plurality of guides. Each guide of the plurality of guides is coupled to a sleeve segment of the plurality of sleeve segments. Each guide is configured to guide the movement of each sleeve segment when the sleeve moves between the forward position and the rearward position. The nozzle assembly further includes but is not limited to an actuator coupled to the sleeve and configured to move the sleeve between the forward position and the rearward position. The inner surfaces of each sleeve segment cooperate with each other to define a path for guiding the mass flow through the sleeve. The circumferential distance between a portion of each sleeve segment varies as the sleeve moves between the forward position and the rearward position. The path has a longitudinal profile with the inner surface of the nacelle that varies as the sleeve moves between the forward position and the aft position. The path has a transverse cross-sectional area that varies as the sleeve moves between the forward position and the aft position.

[0010] In another non-limiting embodiment, the nozzle assembly includes but is not limited to a nacelle. The nozzle assembly further includes but is not limited to a sleeve mounted in the nacelle downstream of the engine. The sleeve is configured to move between a forward position and a rearward position in the nacelle, and is further configured to receive a mass flow from the engine and guide the mass flow to an outlet of the propulsion system. The sleeve is composed of a plurality of sleeve segments. Each sleeve segment in the plurality of sleeve segments is longitudinally aligned and arranged in a circumferential arrangement to form a sleeve. The nozzle assembly further includes but is not limited to a plurality of guides. Each guide in the plurality of guides is coupled to a sleeve segment in the plurality of sleeve segments. Each guide is configured to guide the movement of each sleeve segment when the sleeve moves between the forward position and the rearward position. The nozzle assembly further includes but is not limited to an actuator, which is coupled to the sleeve and is configured to move the sleeve between the forward position and the rearward position. The inner surfaces of each sleeve segment cooperate with each other to define a path for guiding the mass flow through the sleeve. The circumferential distance between a portion of each sleeve segment changes as the sleeve moves between the forward position and the rearward position. The path has a longitudinal profile with the inner surface of the nacelle that changes as the sleeve moves between the forward position and the aft position. The path has a transverse cross-sectional area that changes as the sleeve moves between the forward position and the aft position. A plurality of guides are configured to guide a forward portion of each sleeve segment in a first direction and a rearward portion of each sleeve segment in a second direction.

[0011] In another non-limiting embodiment, the nozzle assembly includes but is not limited to a nacelle. The nozzle assembly further includes but is not limited to a sleeve mounted in the nacelle downstream of the engine. The sleeve is configured to move between a forward position and a rearward position in the nacelle, and is further configured to receive a mass flow from the engine and guide the mass flow to an outlet of the propulsion system. The sleeve is composed of a plurality of sleeve segments. Each sleeve segment in the plurality of sleeve segments is longitudinally aligned and arranged in a circumferential arrangement to form a sleeve. The nozzle assembly further includes but is not limited to a plurality of guides. Each guide in the plurality of guides is coupled to a sleeve segment in the plurality of sleeve segments. Each guide is configured to guide the movement of each sleeve segment when the sleeve moves between the forward position and the rearward position. The nozzle assembly further includes but is not limited to an actuator, which is coupled to the sleeve and is configured to move the sleeve between the forward position and the rearward position. The inner surfaces of each sleeve segment cooperate with each other to define a path for guiding the mass flow through the sleeve. The circumferential distance between a portion of each sleeve segment changes as the sleeve moves between the forward position and the rearward position. The path has a longitudinal profile with the inner surface of the nacelle that changes as the sleeve moves between the forward position and the aft position. The path has a transverse cross-sectional area that changes as the sleeve moves between the forward position and the aft position. A plurality of guides are configured to guide a forward portion of each sleeve segment and a rearward portion of each sleeve segment in parallel directions. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The present invention will be described below with reference to the following drawings, wherein like numerals represent like elements, and

[0013] Figure 1 is a side view showing an aircraft equipped with a propulsion system suitable for use with various non-limiting embodiments of nozzle assemblies made according to the teachings disclosed herein;

[0014] Figure 2 It is shown Figure 1 A schematic transparent view of the propulsion system used by the aircraft;

[0015] Figure 3 It is shown Figure 2 A schematic side view of a nozzle assembly used in a propulsion system;

[0016] Figure 4 is a perspective view showing a first embodiment of a nozzle assembly made according to the teachings disclosed herein, viewed in an upstream direction;

[0017] Figure 5 is a perspective view showing a first embodiment of a nozzle assembly viewed in a downstream direction;

[0018] Figure 6is a perspective view showing a first embodiment of a nozzle assembly arranged in a configuration suitable for takeoff and landing phases of flight;

[0019] Figure 7 is a perspective view showing a first embodiment of a nozzle assembly arranged in a configuration suitable for use in a transonic stage of flight;

[0020] Figure 8 is a perspective view showing a first embodiment of a nozzle assembly arranged in a configuration suitable for use in a supersonic stage of flight;

[0021] Fig. 9 is a cross-sectional view showing internal features of a first embodiment of a nozzle assembly;

[0022] Fig.10 is a partially cut-away cross-sectional view showing a portion of a first embodiment of a nozzle assembly arranged in a configuration suitable for use during takeoff and landing phases of flight;

[0023] Fig.11 is a partially cut-away cross-sectional view showing a portion of a first embodiment of a nozzle assembly arranged in a configuration suitable for transonic flight;

[0024] Fig.12 is a partially cut-away cross-sectional view showing a portion of a first embodiment of a nozzle assembly arranged in a configuration suitable for supersonic flight;

[0025] Fig.13 is a partial view showing a seal member used in a first embodiment of a nozzle assembly;

[0026] Fig.14 is a partial view showing an additional seal employed in the first embodiment of the nozzle assembly;

[0027] Fig.15 is a partial cross-sectional side view showing an additional seal employed by the first embodiment of the nozzle assembly;

[0028] Fig.16 is a perspective view showing a second embodiment of a nozzle assembly made according to the teachings disclosed herein, viewed in an upstream direction;

[0029] Fig.17 is a perspective view showing a second embodiment of a nozzle assembly viewed in a downstream direction;

[0030] Fig.18 is a perspective view showing a second embodiment of a nozzle assembly arranged in a configuration suitable for takeoff, landing, and transonic flight phases;

[0031] Fig.19 is a perspective view showing a second embodiment of a nozzle assembly arranged in a configuration suitable for use in a supersonic phase of flight;

[0032] Fig. 20 is a cross-sectional view showing internal features of a second embodiment of a nozzle assembly;

[0033] Fig.21 is a partially cut-away cross-sectional view showing a portion of a second embodiment of a nozzle assembly arranged in a configuration suitable for takeoff, landing, and transonic flight phases;

[0034] Fig. 22 is a partial cutaway cross-sectional view showing a portion of a second embodiment of a nozzle assembly arranged in a configuration suitable for supersonic flight;

[0035] Fig.23 is a partially cut-away perspective view of a non-limiting embodiment of an actuator suitable for use with the first embodiment of the nozzle assembly and the second embodiment of the nozzle assembly. DETAILED DESCRIPTION

[0036] The following detailed description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. Furthermore, there is no intention to be bound by any theory presented in the preceding background or the following detailed description.

[0037] An improved nozzle assembly for use with a propulsion system is disclosed herein. The nozzle assembly of the present disclosure has a variable geometry that allows it to adopt a variety of configurations and, accordingly, provide desired / optimal nozzle efficiency in a variety of flight conditions, including but not limited to the three flight conditions described above. At the core of the nozzle assembly disclosed herein is a sleeve that is mounted in a nacelle of the propulsion system at the rear of the engine. The inner surface of the sleeve forms a path that the mass flow follows as the mass flow is discharged from the outlet of the engine and moves toward the outlet of the nacelle. The sleeve has an annular or tubular configuration. In a longitudinal cross-section through the sleeve, the sleeve has a profile that includes a protrusion extending in an inward direction toward the centerline of the path. The protrusion creates a localized region where the cross-sectional area of ​​the path is reduced.

[0038] The sleeve is configured to move (translate) longitudinally within the nacelle. Movement of the sleeve longitudinally through the nacelle causes the protruding portion / local region of reduced cross-sectional area of ​​the path to move in a corresponding manner. This ability to control the longitudinal position of the local region of reduced cross-sectional area allows the nozzle assembly to adopt different configurations required to obtain the desired / optimal nozzle efficiency associated with each of the three flight conditions described above. Movement of the sleeve to the desired longitudinal position within the nacelle is determined and controlled by a controller (e.g., a microcontroller, an electronic controller, a computer, etc.), which is operably coupled to an actuator such as a motor, which in turn is configured to move the sleeve.

[0039] The rear portion of the nacelle that houses the sleeve has an external tapered configuration known in the art as a "stern". This external tapered configuration of the nacelle produces an inner surface of the nacelle that also has a tapered configuration in the direction of mass flow (i.e., in the downstream direction). This tapered configuration requires the sleeve to contract circumferentially when the sleeve moves from a forward position within the nacelle to a rearward position within the nacelle. Conversely, the sleeve must expand circumferentially when the sleeve moves from a rearward position within the nacelle to a forward position within the nacelle. In order to achieve circumferential contraction and expansion, the sleeve is composed of a plurality of circumferentially arranged sleeve segments to form the above-mentioned annular or tubular configuration. Each sleeve segment includes a corresponding portion of a protruding portion, and each sleeve segment is arranged relative to each other so that the corresponding portions of their protruding portions are circumferentially aligned to form a composite protruding portion (e.g., a throat).

[0040] To accommodate the different cross-sectional areas that the sleeve must traverse as it moves longitudinally upstream and downstream through the nacelle, in at least one embodiment, each of the plurality of sleeve segments is configured, shaped, and / or sized to be fully or partially circumferentially spaced apart from one another at one longitudinal end of the path, and fully or partially circumferentially adjacent to one another at the opposite longitudinal end of the path. Such sizing and lateral spatial arrangement of each sleeve segment relative to its adjacent sleeve segments facilitates circumferential expansion and contraction of the sleeve as it moves longitudinally through the nacelle.

[0041] When the sleeve moves from one longitudinal position to another longitudinal position within the nacelle, and when individual sleeve segments of the sleeve move partially or completely apart from each other, gaps are formed between the sleeve segments. In addition, due to limitations associated with manufacturing capabilities, there are gaps between the leading edge of each sleeve segment of the sleeve and the inner surface of the nacelle. In addition, in embodiments of the nozzle assembly, in which the individual sleeve segments employ track followers to follow tracks that are coupled to the inner surface of the nacelle or defined within the inner surface of the nacelle and are designed to guide the movement of the individual sleeve segments, such tracks also constitute gaps. If not controlled, these gaps will form paths that will siphon and / or redirect part of the mass flow and result in losses that will reduce the efficiency of the nozzle assembly. Therefore, the nozzle assembly includes a plurality of seals to close the above-mentioned gaps to prevent such losses.

[0042] Two embodiments of the nozzle assembly are disclosed herein. Although only two embodiments are discussed and disclosed herein, it should be understood that other embodiments may be employed without departing from the teachings disclosed herein.

[0043] In one embodiment, the individual sleeve segments are guided to move longitudinally through the nacelle by tracks coupled to or defined in the inner surface of the nacelle. Each individual sleeve segment has at least one track follower configured to engage the track and guide the longitudinal movement of each segment. In this embodiment, the track followed by the track followers is longitudinally straight and aligned with the inner surface of the nacelle. As the sleeve segments move longitudinally back and forth within the nacelle, they guide the sleeve segments and maintain the longitudinal orientation of each individual sleeve segment constant, effectively repositioning and resizing the protruding portion and the locally reduced cross-sectional area as the sleeve moves without changing its longitudinal profile. In this embodiment, when the sleeve is in the full forward position, the protruding portion is in its longitudinal forward most position, and due to the circumferential expansion of the sleeve at this longitudinal position of the nacelle, the locally reduced cross-sectional area of ​​the path has a cross-sectional area equal to the cross-sectional area of ​​the exit plane. This configuration results in a converging configuration of the path together with the inner surface of the nacelle downstream of the path, which is most efficient during the first flight regime when the aircraft takes off from the runway and climbs out of the airspace surrounding the airport. Figures 16 to 22 , and discussed in detail below), this converging configuration, while not ideally suited for the second flight regime, is optimal during the second flight regime when the aircraft is flying at transonic speeds because it avoids shocks and flow separation within the nozzle assembly. When the sleeve of this first embodiment moves to its rearmost position, the locally reduced cross-sectional area of ​​the path has a smaller cross-sectional area than the cross-sectional area of ​​the exit plane due to the circumferential contraction of the sleeve at this longitudinal position of the nacelle. This configuration results in the path having a converging-diverging configuration, which is most efficient during the third flight regime when the aircraft is flying at supersonic speeds. Although this embodiment is described as being suitable for use with takeoff, transonic and supersonic flight regimes, it should be understood that the sleeve can be positioned at any suitable longitudinal position within the nacelle at the rear of the engine to optimize nozzle performance during any other / additional flight regime in which the aircraft may operate. In this embodiment, the sleeve always remains at or forward of the exit plane of the nacelle.

[0044] In another embodiment, the track followed by the path follower has a curvature that is configured to cause the sleeve to change its geometry in a manner that best adapts to all three flight conditions. In this other embodiment, when the sleeve is in its final position, the rear portion of the sleeve partially extends downstream of the exit plane of the nacelle, and by doing so, the rear end of the sleeve becomes the exit plane of the propulsion system. In this final position, the track brings the individual sleeve segments into a position that results in a locally reduced cross-sectional area, and the remaining portion of the sleeve downstream of the locally reduced cross-sectional area has a constant cross-sectional area. This results in the path having a converging configuration together with the inner surface of the nacelle that excludes mass flow from becoming supersonic. This configuration is most efficient during the first flight condition when the aircraft takes off and climbs out of the airspace around the airport. When the sleeve moves to an intermediate longitudinal position within the nacelle, the track reconfigures the sleeve so that the locally reduced cross-sectional area is now slightly smaller than the cross-sectional area of ​​the exit plane of the propulsion system. In other words, when the rear portion of the sleeve tilts outward, the narrowest part of the sleeve shrinks. This arrangement of the sleeves results in a nozzle assembly having a minimum convergence-divergence configuration. As used herein, the term "minimum convergence-divergence configuration" refers to a configuration that is optimal for maintaining transonic flight. As is well known in the art, this is determined by the ratio of the total pressure (also referred to as the stagnation pressure in the case of gases) to the free stream static pressure (also referred to as the ambient pressure) into which the engine exhausts. When these pressures are known, the Mach number can be determined using the following equation:

[0045] p / pt=[1+M^2*(gam-1) / 2]^-[gam / (gam-1)]

[0046] Once the Mach number is calculated using the above equation, substitute that Mach number into the following equation to solve for the left side of the equation (A / A*):

[0047] A / A*={[1+M^2*(gam-1) / 2]^[(gam+1) / (gam-1) / 2]}*{[(gam+1) / 2]^-[(gam+1) / (gam-1) / 2]} / M

[0048] "A / A*" refers to the outlet area (A) divided by the throat area (A*) (also known as A9 / A8). Therefore, the maximum ratio applicable to transonic operation is a function of the free stream static pressure (ambient pressure) and the engine total pressure (stagnation pressure) calculated using the above isentropic equation. The designer can select the desired Mach number for transonic flight, and knowing the stagnation pressure at a predetermined throttle position and knowing the ambient pressure at a predetermined altitude, the designer can determine where to position the main curve of the sleeve within the nozzle to produce the maximum ratio that will generate the desired Mach number. This minimum convergence-divergence configuration produces a relatively low-thrust supersonic flow, which is very suitable for efficient operation during the second flight state when the aircraft is flying at transonic speeds. The A / A* value calculated using the aforementioned method takes into account ideal operation, however losses in real-world environments require small adjustments to the final A / A* value to achieve optimal performance. As the sleeve moves along the path to the forward-most longitudinal position, the track causes the sleeve to be further reconfigured so that the locally reduced cross-sectional area has a smaller diameter than its diameter at the intermediate position. The track also causes the cross-sectional area of ​​the rear portion of the sleeve to be further expanded compared to its cross-sectional area at the intermediate position. This produces a maximum convergence-divergence configuration, which in turn produces a relatively high thrust, which is very suitable for efficient operation during the third flight state when the aircraft is flying at supersonic speeds. As used herein, the term "maximum convergence-divergence configuration" refers to the maximum possible ratio of the cross-sectional area of ​​the exit plane to the locally reduced cross-sectional area, which can be achieved based on the physical and structural limitations imposed by the track. As described above, although this embodiment is described as being suitable for use with takeoff / climb flight states and transonic flight states and supersonic flight states, it should be understood that the sleeve can be positioned at any suitable position along the nacelle to optimize nozzle performance during any other / additional flight states in which the aircraft can operate.

[0049] In addition to ensuring peak efficiency of the nozzle under various flight conditions, another advantage derived from the variable area ratio capability of the disclosed nozzle assembly is that increasing the nozzle throat area increases the fan stall margin, which allows additional fan distortion tolerance during low-speed (i.e., takeoff) operations with cross wind or other causes of inlet distortion.

[0050] Furthermore, increasing the nozzle throat (A8) reduces the nozzle exit velocity, which is a strong driver of takeoff noise. Furthermore, ensuring a fully converging nozzle at takeoff also ensures that the nozzle exit velocity does not exceed Mach 1.0 which would significantly increase the overall takeoff noise of the aircraft.

[0051] A better understanding of the above-described propulsion system and method of making the propulsion system may be obtained by reviewing the drawings attached hereto and reviewing the detailed description that follows.

[0052] Figure 1 3 is a side view showing an aircraft 30 equipped with a propulsion system 32. The propulsion system 32 is suitable for use with various non-limiting embodiments of nozzle assemblies made according to the teachings disclosed herein and discussed in detail below. The aircraft 30 is configured for flight at subsonic, transonic, and supersonic speeds. The propulsion system 32 is configured to provide the aircraft 30 with thrust suitable for propelling the aircraft 30 at subsonic, transonic, and supersonic speeds.

[0053] Continue to refer Figure 1 , Figure 2 3 is a schematic transparent view showing a propulsion system 32. The propulsion system 32 includes an air intake 34, a nacelle 36, an engine 38, and a nozzle assembly 40. The air intake 34 is configured to capture air from free stream air and direct the captured air to the engine 38. The engine 38 is configured to compress the captured air, add fuel to the captured air, and burn the captured air to generate a heated high-energy mass flow that can be used to apply thrust to the aircraft 30. The engine 38 is further configured to direct the high-energy mass flow downstream into the nozzle assembly 40. In some embodiments, the propulsion system 32 may further include one or more turbines that are driven by the high-energy mass flow and in turn drive a fan at an upstream position within the propulsion system to generate additional thrust. The nozzle assembly 40 is configured to receive the high-energy mass flow from the engine 38, direct the high-energy mass flow to an outlet 42 of the propulsion system 32, and focus the high-energy mass flow as discussed in detail below to generate different thrust amounts.

[0054] Continue to refer Figure 1-Figure 2 , Figure 3 4 is a schematic side view showing the nozzle assembly 40 in more detail. The nozzle assembly 40 includes a portion of the nacelle 36, a sleeve 44, an actuator 46, a controller 48 and a control unit 48 which will be described below. Fig. 9 and Fig. 20 A description of the multiple guides discussed.

[0055] The sleeve 44 may be made of any material suitable for maintaining its shape / contour when exposed to mass flow having the temperature imparted by the jet engine. The sleeve 44 is configured to move back and forth between an aft position (shown in solid lines) and a forward position (shown in dashed lines) in the direction indicated by the double-headed arrow 45. The sleeve 44 is composed of an assembly of longitudinally aligned and circumferentially arranged individual sleeve segments that cooperate with each other to form an annular tubular structure that can conform or adapt to the inner surface of the nacelle 36. The individual sleeve segments are not arranged in a Figure 3 shown in Figure 4-Figure 22. The individual sleeve segments are configured to at least partially move circumferentially relative to each other. As the sleeve 44 moves from the aft position to the forward position, the diameter and cross-sectional area of ​​the nacelle 36 expand due to the frustoconical configuration of the aft portion of the nacelle 36. To accommodate this increased diameter and cross-sectional area, the individual sleeve segments are configured to at least partially move circumferentially away from each other, thereby at least partially expanding the diameter of the sleeve 44. As the sleeve 44 moves from the forward position to the aft position, this phenomenon is reversed and the diameter and cross-sectional area of ​​the nacelle 36 decreases. To accommodate this reduced diameter and reduced cross-sectional area, as the sleeve 44 moves downstream, the individual sleeve segments are configured to at least partially move circumferentially toward each other, thereby at least partially contracting the diameter of the sleeve 44.

[0056] The inner surface 50 of the sleeve 44 is composed of the combination of the inner surfaces of each of the individual sleeve segments. These inner surfaces cooperate to form a path 52 that, together with the inner surface of the nacelle 36, directs the high energy mass flow from the engine 38 to the outlet 42. Each individual sleeve segment has a substantially identical profile, including a main curve in the longitudinal direction, such as Figure 10-12 and Figure 21-22 4. These master curves together form the region of the sleeve 44 having the smallest cross-sectional area. Depending on the position of the sleeve 44 and its expanded and contracted states, this region may also constitute the throat of the nozzle assembly 40. The precise configuration of the path 52 and its ability to focus mass flow in a manner that generates subsonic, transonic, and supersonic exhausts that produce corresponding thrust levels is determined by a number of guides (described below), the contracted or expanded state of the sleeve 44, the longitudinal position of the sleeve 44 within the nacelle 36, and accordingly the position of the region of the smallest cross-sectional area of ​​the sleeve 44 within the nacelle 36. For ease of illustration, the master curves, the smallest cross-sectional area, and the varying configurations of the path 52 are not shown in this schematic diagram, but are presented in subsequent illustrations throughout the remainder of the present disclosure.

[0057] The actuator 46 may include any machine or mechanism that effectively generates and transmits force to the sleeve 44 to move the sleeve 44 forward and aft within the nacelle 36. In an embodiment and without limitation, the actuator 46 may include an electric motor. The nozzle assembly 40 may employ any other type of actuator, whether now known or later invented, without departing from the teachings of the present disclosure.

[0058] Controller 48 may be any type of onboard computer, controller, microcontroller, circuit, chipset, computer system, or microprocessor configured to execute algorithms, execute software applications, execute subroutines, and / or be loaded and execute any other type of computer program. Controller 48 may include a single processor or multiple processors acting in coordination. In some embodiments, controller 48 may be dedicated for use only with nozzle assembly 40, while in other embodiments, controller 48 may be shared with other systems on aircraft 30.

[0059] The controller 48 is operably coupled to the actuator 46 and may be communicatively coupled to other systems, controllers, and / or sensors on the aircraft 30, including, but not limited to, a primary flight control system configured to receive crew input indicating a desired speed for the aircraft 30. Such coupling may be accomplished using any suitable transmission means, including both wired and wireless connections. For example, each component may be physically connected to the processor 34 via a coaxial cable or via any other type of wired connection that effectively transmits signals. In the illustrated embodiment, the controller 48 is operably coupled directly to the actuator 46. In other embodiments, the actuator 46 may be coupled to the controller 48 across a vehicle bus. In other examples, the actuator 46 may be wirelessly coupled to the controller 48 via a Bluetooth connection, a WiFi connection, or the like.

[0060] The operative coupling provides a path for transmitting commands, instructions, queries, and other signals between the controller 48 and the actuator 46. Through this coupling, the controller 48 can control the actuator 46 and / or communicate with the actuator 46. The actuator 46 can be configured to interface and engage with the controller 48. For example, in some embodiments, the actuator 46 can be configured to receive commands from the controller 48 and automatically provide information related to the longitudinal position of the sleeve 44 to the controller 48, or provide such information in response to a query received from the controller 48.

[0061] Controller 48 is configured to interact with, coordinate, and / or orchestrate the activities of actuator 46 for the purpose of controlling the amount of thrust delivered by propulsion system 32. Controller 48 may be programmed and / or otherwise configured to receive information indicative of a desired speed for vehicle 30, and may be further configured to control actuator 46 to move sleeve 44 to a longitudinal position within nacelle 36 that will focus the high-energy mass flow in a manner that will generate an amount of thrust suitable for propulsing vehicle 30 at the desired speed. In some embodiments, to generate the necessary thrust, controller 48 may instruct actuator 46 to move sleeve 44 from a rearmost position to a forwardmost position, or vice versa, or to any other position suitable for generating an amount of thrust corresponding to the desired speed. In a non-limiting embodiment, controller 48 may be programmed with or have access to an a priori lookup table that associates each possible longitudinal position of sleeve 44 within nacelle 36 with a corresponding amount of thrust to be generated at each possible throttle position. In such an example, when a crew member selects a throttle position, controller 48 may access the lookup table and, based on the information available on the lookup table, controller 48 may instruct actuator 46 to move sleeve 44 to a longitudinal position within nacelle 36 that will cause path 52 to have a longitudinal and lateral configuration suitable for generating an amount of thrust consistent with the selected throttle position.

[0062] In other embodiments, sensors associated with the propulsion system 32 or sensors located elsewhere on the aircraft 30 may be employed that provide feedback to the controller 48 regarding the amount of thrust generated by the propulsion system 32. The controller 48 may be configured to use this feedback to determine the deviation between the amount of thrust currently being generated and the amount of thrust requested by the crew, and may be further configured to control the actuator 46 to move the sleeve 44 in a direction that longitudinally repositions the sleeve 44 within the nacelle 36 to generate a new thrust that will reduce the deviation between the current thrust and the desired thrust. This process may repeat itself in an iterative manner until the desired thrust is achieved or until the deviation drops below an acceptable level. In some embodiments, a sensor associated with the propulsion system 32 may be configured to detect the position of the sleeve 44 within the nacelle 36 and transmit information indicative of the position of the sleeve 44 to the controller 48. In such an embodiment, the controller 48 may be configured to receive information indicative of the position of the sleeve 44 from the sensor and use this information to confirm whether the sleeve 44 has moved to the commanded position. In instances where the controller 48 determines that the sleeve 44 has not moved to the commanded position, the controller 48 is configured to generate a crew alert system (CAS) message and communicate the CAS message to the flight crew. In other embodiments, the controller 48 may employ any other suitable method to control the actuator 46 in a manner that causes the propulsion system 32 to generate the thrust required to propel the aircraft 30 at the desired speed.

[0063] exist Figure 3 Although both the actuator 46 and the controller 48 are shown in a position spaced apart from the nacelle 36 and the sleeve 44, it should be understood that in embodiments, the actuator 46 and the controller 48 may be housed in any suitable location, including but not limited to being housed within the nacelle 36, being mounted on the sleeve 44, being mounted elsewhere on the propulsion system 32, being housed within a pylon (not shown), or being mounted to any other suitable portion of the aircraft 30 without departing from the teachings of the present disclosure.

[0064] Continue to refer Figure 1-Figure 3 , Figure 4 is a perspective view showing an embodiment of a nozzle assembly 60 made according to the teachings disclosed herein. In this view, the nozzle assembly 60 is presented with the outlet 62 facing the viewer and oriented in a manner that allows the viewer to view the rear end of the nozzle assembly 60 upstream.

[0065] The nozzle assembly 60 includes a nacelle 64 and a sleeve 66 mounted therein and coupled in a manner that allows the sleeve 66 to translate forwardly and aft within the nacelle 64. The sleeve 66 is composed of a plurality of individual, substantially identical sleeve segments 68 that are longitudinally aligned with one another, oriented so that their longitudinal axes are aligned with the direction of mass flow, and circumferentially arranged to form a cylindrical tubular structure that, together with the inner surface of the nacelle 64, is configured to direct the mass flow through the nozzle assembly 60 to the outlet 62. Figure 4 In the embodiment, the sleeve 66 is arranged at the forwardmost position in the nacelle 64. Figure 4 In the embodiment of the present invention, the controls and actuators of the nozzle assembly 60 are not visible and can be mounted at any suitable location on the aircraft.

[0066] Continue to refer Figure 1-Figure 4 , Figure 5 is a perspective view showing the nozzle assembly 60 viewed in the downstream direction. Figure 5 In FIG, sleeve 66 is again shown in the forward most position. Figure 5 In the embodiment of the present invention, it can be observed that the front portions of each individual sleeve segment 68 are arranged in close proximity to each other, while the rear portions of each individual sleeve segment 68 are spaced apart from each other. This is the result of a combination of the curvature of each sleeve segment 68 and the orientation of each sleeve segment 68, as discussed in detail below.

[0067] Continue to refer Figure 1-Figure 5 , Figure 6is a perspective view showing the nozzle assembly 60 arranged in a configuration suitable for takeoff and landing phases of flight. In this configuration, the sleeve 66 is disposed in its rearward position. The rearward portions of each sleeve segment 68 are now disposed in close circumferential proximity to one another, and the forward portions of each sleeve segment 68 are now circumferentially spaced apart from one another. As discussed in detail below, this is because the plurality of guides guiding each individual sleeve segment 68 have moved the rearward end of each sleeve segment 68 inwardly to a greater extent than the guides have moved the forward end of each sleeve segment 68 inwardly, such that each sleeve segment 68 has in effect pivoted its rearward end inwardly (inwardly, toward the center of the sleeve 66) and its forward end outwardly (outwardly, away from the center of the sleeve 66). When the sleeve 66 is in its rearward position within the nacelle 64, the rearward portion of the sleeve 66 extends beyond the rearward portion of the nacelle 64 and, therefore, becomes the outlet 62 of the propulsion system 32. In this configuration, the main curve of each individual sleeve segment 68 (see Figure 9-12 ) forms the minimum cross-sectional area of ​​sleeve 66. The cross-sectional area of ​​sleeve 66 upstream of the main curve has a divergent configuration in the upstream direction, and the cross-sectional area of ​​sleeve 66 downstream of the main curve remains constant in the downstream direction. In this configuration, the mass flow through nacelle 64 follows a path that will converge when the mass flow initially encounters sleeve 66 and will continue to converge until the mass flow reaches the main curve. As the mass flow continues downstream of the main curve, the path will have a constant diameter all the way to outlet 62. Therefore, after moving through the main curve, the mass flow will neither converge nor diverge in its remaining passage through sleeve 66. In some embodiments, the path can have a slightly converging configuration all the way to outlet 62. In any of these configurations, the mass flow is excluded from becoming supersonic because, with sleeve 66 in the final position, nozzle assembly 60 does not include a divergent portion behind the main curve. This configuration is very suitable for takeoff and landing of an aircraft because the lack of supersonic flow ensures that the noise generated by the propulsion system will be relatively low and in compliance with local ordinances and jurisdictional laws.

[0068] Continue to refer Figure 1-Figure 6 , Figure 7 is a perspective view showing the nozzle assembly 60 arranged in a configuration suitable for use in a transonic flight phase. Figure 7 In FIG. 6 , the sleeve 66 has been partially moved upstream to an intermediate position within the nacelle 64. As the sleeve 66 moves upstream, each sleeve segment 68 is guided by its corresponding guide (see FIG. 6 ). Fig. 9) moves in a manner that changes the inboard and outboard relationship between the forward-most and rearward-most ends of each sleeve segment 68. The guide is configured to move the rearward-most end of each sleeve segment 68 in an outboard direction relative to the forward-most end of each sleeve segment 68, and to move the forward-most end of each sleeve segment 68 in an inboard direction relative to the rearward-most end of each sleeve segment 68. Throughout the pivotal movement of each sleeve segment 68, the main curve maintains the minimum cross-sectional area of ​​the sleeve 66. However, in Figure 7 In the position / configuration shown in , there is now a slight divergence in the path that the mass flow follows in the rear portion of the main curve due to the change in orientation of each sleeve segment 68 . Figure 7 The configuration shown in is referred to herein as the minimum convergence-divergence configuration and includes configurations that can be derived using the above methods, equations, and protocols. This minimum convergence-divergence configuration generates a slightly supersonic flow at the outlet 62 and is well suited to overcoming the drag rise encountered by an aircraft when traveling at transonic speeds.

[0069] The relative outward pivotal movement of the rear end of each sleeve segment 68 causes the rear end of each sleeve segment 68 to move circumferentially away from each other. At the same time, the relative inward pivotal movement of the forward end of each sleeve segment 68 causes the forward end of each sleeve segment 68 to move circumferentially toward each other. Figure 7 , there is now a gap between the rearmost ends of each sleeve segment 68. Accordingly, the gap that existed between the forward ends of the sleeves 68 when the sleeves 66 were disposed in their rearmost positions within the nacelle 64 has now been reduced.

[0070] Continue to refer Figure 1-Figure 7 , Figure 8 is a perspective view showing the nozzle assembly 60 arranged in a configuration suitable for use in a supersonic flight regime. Figure 8 6, the sleeve 66 has moved upstream to its forwardmost position within the nacelle 64. As the sleeve 66 moves upstream to its forwardmost position, each sleeve segment 68 is guided by its corresponding guide (see FIG. Fig. 9 ) moves in a manner that further changes the inboard and outboard relationship between the forward-most and rearward-most ends of each sleeve segment 68. The guide is configured to cause the rearward-most end of each sleeve segment 68 to continue to move in the outboard direction relative to the forward-most end of each sleeve segment 68, and to cause the forward-most end of each sleeve segment 68 to continue to move in the inboard direction relative to the rearward-most end of each sleeve segment 68. As previously described, the main curve maintains the minimum cross-sectional area of ​​the sleeve 66. When in Figure 8 In the position / configuration shown in , due to the further change in the orientation of each sleeve segment 68, the path followed by the mass flow downstream of the main curve now has a maximum divergence. Figure 8The configuration shown in FIG. 6 is referred to herein as a maximum convergence-divergence configuration and comprises a configuration in which the area ratio between the rear end of the sleeve 66 and the cross-sectional area at the main curve is of the maximum magnitude that can be obtained by guiding each sleeve segment 68 through the guide. This maximum convergence-divergence configuration generates a high speed supersonic flow at the outlet 62 and is well suited for sustained supersonic flight of the aircraft 30.

[0071] Further relative outward pivotal movement of the rearmost ends of each sleeve segment 68 causes the rearmost ends of each sleeve segment 68 to move further circumferentially away from each other. At the same time, relative inward pivotal movement of the forward ends of each sleeve segment 68 causes the forward ends of each sleeve segment 68 to move further circumferentially toward each other to a point where the forward ends are immediately adjacent to each other and, in some embodiments, directly contact each other. Thus, when the sleeve 66 is positioned Figure 8 , the gap between the rearmost ends of each sleeve segment 68 is at its widest, whereas the gap between the forwardmost ends of the sleeves 68 that previously existed when the sleeves 66 were positioned downstream of their forwardmost position within the nacelle 64 has now dissipated.

[0072] Continue to refer Figure 1-Figure 8 , Fig. 9 is a cross-sectional view showing a guide 70 of the nozzle assembly 60. In the illustrated embodiment, the guide 70 is composed of a front track 72 and a rear track 74. The front track 72 and the rear track 74 are coupled to the nacelle 64 and are configured to guide each sleeve segment 68 when the sleeve 66 moves between its forward most position and its rearward most position. From the perspective of the upstream direction, the front track 72 and the rear track 74 are both inclined inwardly, wherein the front track 72 is inclined at a greater angle than the rear track 74. The front portion of the sleeve segment 68 is equipped with a track follower 76, which is configured to travel within the front track 72, thereby guiding the front end of the sleeve segment 68 when the sleeve segment 68 moves forward and backward. Similarly, the rear portion of the sleeve segment 68 is equipped with a track follower 78, which is configured to travel within the rear track 74, thereby guiding the rear end of the sleeve segment 68 when the sleeve segment 68 moves forward and backward. Because the forward and aft rails 72, 74 are inclined inwardly at different angles, the forward and aft ends of the sleeve segment 68 move inwardly and outwardly to a greater and lesser extent, respectively, resulting in relative pivotal movement of the forward and aft ends of the sleeve segment 68 about a central region of the sleeve segment 68 as the sleeve segment 68 moves forwardly and aft within the nacelle 64. This creates a selectively variable longitudinal path for mass flow to follow through the sleeve 66 having a longitudinal configuration that varies with the position of the sleeve 66 within the nacelle 64.

[0073] Continue to refer Figure 1-Figure 9 , Fig.10 , Fig.11 and Fig.126 is a partially cutaway cross-sectional view showing a portion of the nozzle assembly 60 as the sleeve 66 moves from the rearmost position to the intermediate position and then to the forwardmost position within the nacelle 64. These views respectively show the movement of the sleeve 66 as the sleeve 66 is positioned in the Figure 6 The last position of Figure 7 The middle position and Figure 8 The continuous convergence path, the minimum convergence-divergence path and the maximum convergence-divergence path generated by the most forward position.

[0074] Fig.10 The nozzle assembly 60 is shown with the sleeve 66 disposed in the rearward position. In this view, the main curve 80 of the sleeve segment 68 can be best seen. The portion of the sleeve segment 68 forward of the main curve 80 diverges in the upstream direction, and the portion of the sleeve 68 downstream of the main curve 80 is straight. The rearward end 82 of the sleeve 66 extends beyond the rearward end 84 of the nacelle 64, so that the rearward end 82 becomes the outlet 62 of the propulsion system. As shown in FIG. Fig.10 As shown in FIG. 1 , when the sleeve 66 is disposed in its rearmost position within the nacelle 64, the throat (A8) of the nozzle assembly 68 is juxtaposed with the exit plane (A9) of the nozzle assembly 68. Because the throat and the exit plane are in Fig.10 The nozzle assembly 60 is juxtaposed in the configuration shown in the figure, so when in the configuration shown, the nozzle assembly 60 generates a subsonic mass flow. This makes the configuration shown very suitable for the takeoff and landing phases of flight.

[0075] Fig.11 The nozzle assembly 60 is shown with the sleeve 66 disposed in an intermediate position as described above. The forward track 72 causes the forward portion of each sleeve segment 68 to move in an inboard direction. The aft track 74 has a lesser inward inclination, so the aft end of the sleeve segment 68 moves inward less than the forward end of the sleeve segment 68. This causes a change in the longitudinal orientation of each sleeve segment 68, which in turn creates a minimal convergent-divergent path through the sleeve 66. The aft end 82 of the sleeve 66 continues to extend beyond the aft end 84 of the nacelle 64, but extends less than the aft end 84 of the nacelle 64 as the sleeve 66 moves upstream relative to the nacelle 64. Fig.10 In addition, due to the inward pivoting of the front ends of the sleeve segments 68, the throat (A8) of the nozzle assembly 60 is now located at the main curve 80, and the portion of each sleeve segment 68 downstream of the main curve 80 creates a slightly divergent configuration, which allows the mass flow to be accelerated to supersonic speeds. This configuration is very suitable for the transonic flight stage.

[0076] Fig.12The nozzle assembly 60 is shown with the sleeve 66 disposed in the forward most position as described above. The forward track 72 causes the forward portion of each sleeve segment 68 to move further in the inboard direction. The rearward track 74, which has a smaller inward inclination, causes the rear end of each sleeve segment 68 to move inward to a lesser extent. This causes a further change in the longitudinal orientation of each sleeve segment 68, which produces a maximum convergent-divergent path through the sleeve 66. The rear end 82 of the sleeve 66 is now located within the rear end 84 of the nacelle 64, and thus the rear end 84 of the nacelle 64 now includes the outlet 62 of the propulsion system. As the forward end of the sleeve segment 68 is further pivoted inward, the throat (A8) of the nozzle assembly 60 remains located at the main curve 80 and now has the narrowest cross-sectional area possible. The portion of each sleeve segment 68 downstream of the main curve 80 produces a greater divergent configuration than that present when the sleeve 66 is in the intermediate position. This results in an increase in the ratio between the cross-sectional area of ​​the outlet 62 and the throat (A8) juxtaposed with the main curve 80. This increased ratio allows the mass flow to be accelerated to greater supersonic speeds than would be achieved when the sleeve 66 is in the intermediate position. This configuration is well suited for the supersonic phase of flight.

[0077] Continue to refer Figure 1-Figure 11 , Fig.13 is a partial view showing a plurality of seals 90 employed by the nozzle assembly 60. The plurality of seals 90 may be made of any material suitable for maintaining its shape / contour when exposed to a mass flow having a temperature imparted by a supersonic jet engine. The plurality of seals 90 are configured to engage with the lateral ends of the sleeve segments 68, and the sleeve segments 68 are configured to engage with the plurality of seals 90. In an embodiment, there is a tongue-and-groove arrangement between the plurality of seals 90 and the sleeve segments 68. As the lateral ends of each sleeve segment 68 move away from the lateral ends of each adjacent sleeve segment 68, the plurality of seals 90 are uncovered and serve to prevent any portion of the mass flow from flowing between the spaced apart portions of each sleeve segment 68.

[0078] In an embodiment, the lateral end portions of each individual segment 68 may be indented to reduce its thickness. Then, a strip of material may be coupled to the lateral ends of each individual segment 68 immediately above the indented portion to form a slot between the strip of material and the lateral ends of the individual segment. Then, a strip of sealing material may be inserted into the slot of each pair of adjacent individual segments. When two individual sleeve segments 68 are pressed against each other, the slot will have a sufficient depth to accommodate the strip of sealing material (individual seals 90), and the strip of sealing material will have a sufficiently wide width to prevent the strip of sealing material from coming out of the slot when the sleeve segment 68 is in a position that results in a gap between the individual segments 68.

[0079] Continue to refer Figure 1-Figure 13 , Fig.14is a partial view showing a plurality of seals 92 employed by the nozzle assembly 60 to inhibit mass flow into the front and rear tracks 72, 74 if and when the front and rear tracks 72, 74 are exposed when the front or rear end of the sleeve 66 passes behind or in front of the tracks, respectively. The plurality of seals 92 may be made of any material suitable for maintaining its shape / contour when exposed to mass flow having the temperatures imparted by a supersonic jet engine. In an embodiment, there may be two opposing seals positioned in the front and rear tracks 72, 74, each opposing seal having a P-shaped configuration. The two opposing seals separate when the track followers 76 and 78, respectively, pass between them, and then come back together and press against each other when the track followers pass by.

[0080] Continue to refer Figure 1-Figure 14 , Fig.15 6 is a partially cut-away side view showing a seal 94 employed by the nozzle assembly 60 to inhibit mass flow from passing between the outer side 96 of the leading edge 97 of each sleeve segment 68 and the inner surface 98 of the nacelle 64. The seal 94 may be made of any material suitable for maintaining its shape / contour when exposed to mass flow having the temperatures imparted by a supersonic jet engine. In an embodiment, the seal 94 is coupled to the leading edge 97 of each sleeve segment 68 and is located between the outer side 96 of the leading edge 97 of each sleeve segment 68 and the inner surface 98 of the nacelle 64. As the sleeve 66 moves upstream and downstream through the nacelle 64, the seal 94 slides into engagement with the inner surface 98 of the nacelle 64. The seal 94 inhibits direct contact between each individual sleeve segment 68 and the inner surface 98, thereby reducing wear on the leading edge 97 of each sleeve segment 68.

[0081] Continue to refer Figure 1-Figure 15 , Fig.16 is a perspective view showing another embodiment of a nozzle assembly 100 made according to the teachings disclosed herein. In this view, the nozzle assembly 100 is presented with the outlet 102 facing the viewer and oriented in a manner that allows the viewer to view the rear end of the nozzle assembly 100 upstream.

[0082] The nozzle assembly 100 includes a nacelle 104 and a sleeve 106 mounted therein and coupled in a manner that allows the sleeve 106 to translate forwardly and aft within the nacelle 104. The sleeve 106 is composed of a plurality of individual, substantially identical sleeve segments 108 that are longitudinally aligned with one another, oriented so that their longitudinal axes are aligned with the mass flow, and circumferentially arranged to form an annular tubular structure that, together with the inner surface of the nacelle 104, is configured to direct the mass flow through the nozzle assembly 100 to the outlet 102. Fig.16 In FIG. 1 , sleeve 106 is disposed in a rearmost position within nacelle 104. Fig.16In the embodiment of the present invention, the controls and actuators of the nozzle assembly 100 are not visible and can be mounted at any suitable location on the aircraft.

[0083] Continue to refer Figure 1-Figure 16 , Fig.17 is a perspective view showing the nozzle assembly 100 viewed in the downstream direction. Fig.17 In FIG, the sleeve 106 is again shown in the rearmost position. Fig.16 and Fig.17 In FIG. 1 , it can be observed that the two transverse ends of each individual sleeve segment 108 are arranged adjacent to each other. This results in the sleeve 106 being arranged at the downstream end of the nacelle 104, where the diameter of the nacelle 104 is at a minimum, which causes the sleeve 106 to be correspondingly contracted to its minimum diameter.

[0084] Continue to refer Figure 1-Figure 17 , Fig.18 is a perspective view showing the nozzle assembly 100 arranged in a configuration suitable for takeoff, landing, and transonic flight phases. In this configuration, the sleeve 106 is disposed in its forward-most position. The two lateral ends of each sleeve segment 108 are spaced apart from the lateral ends of each of its adjacent sleeve segments 108. As described below, this is because the multiple guides that guide each individual sleeve segment 108 guide both the forward portion and the rearward portion of each sleeve segment 108 in parallel directions along the inner surface of the frustoconical portion of the nacelle 104. At the forward end of the nacelle 104, where the diameter and cross-sectional area of ​​the nacelle 104 are largest, the diameter and cross-sectional area of ​​the sleeve 106 are correspondingly largest. In order to accommodate this increased diameter, the individual sleeve segments 108 must be moved laterally away from each other. In this configuration, the main curve of each individual sleeve segment 108 (see Figure 20-22 ) forms the minimum cross-sectional area of ​​the sleeve 106. The longitudinal cross-section of the sleeve 106 upstream of the main curve has a diverging profile in the upstream direction, and in the downstream direction, behind the main curve, it has a diverging profile again. Downstream of the sleeve 106, the inner surface of the nacelle 104 has a converging configuration. At the main curve or throat of the sleeve 106, the diameter is greater than the diameter of the outlet 102. Therefore, at Fig.18In the configuration shown in FIG. 1 , the mass flow through the nacelle 104 follows a path where the mass flow will converge when it initially encounters the sleeve 106 until it reaches the main curve, and will then diverge until it leaves the sleeve 106. At this point, the mass flow will encounter the inner surface of the nacelle 104, which will again cause the mass flow to continue to converge until it reaches the outlet 102. In this configuration, the mass flow is excluded from becoming supersonic because the diameter of the throat (i.e., the narrowest portion of the sleeve 106 juxtaposed with the main curve) is not less than the diameter of the outlet 102 with the sleeve 106 in the forward-most position. This configuration is well suited for takeoff and landing of an aircraft because the lack of supersonic flow ensures that the noise generated by the propulsion system will be relatively low and in compliance with local ordinances and jurisdictional laws. This configuration is also well suited for transonic flight because it moves at the speed of sound, so it avoids shock and separation flows that could inadvertently be caused if the flow becomes supersonic and is then forced through a section with a converging region.

[0085] Continue to refer Figure 1-Figure 18 , Fig.19 is a perspective view showing the nozzle assembly 100 arranged in a configuration suitable for use in a supersonic flight regime. Fig.19 1, the sleeve 106 has moved downstream to its final position within the nacelle 104. As the sleeve 106 moves downstream toward its final position, each sleeve segment 108 is guided by its corresponding guide (see Fig. 20 ) is moved in a manner that circumferentially contracts the sleeve 106 by bringing each individual sleeve segment 108 laterally closer to its adjacent sleeve segment. When the sleeve 106 reaches its rearward position, each sleeve segment 108 is disposed in close proximity to one another, and in an embodiment, in direct contact with one another. The guide is configured to move the front of each sleeve segment 108 and the rear of the sleeve segment 108 in parallel directions so that the sleeve 106 translates between its forward most position and its rearward most position without changing the longitudinal orientation of any individual sleeve segment 108. As previously described, the main curve maintains the minimum cross-sectional area of ​​the sleeve 106. However, when the sleeve 106 is in Fig.19 , the cross-sectional diameter of the throat of the sleeve 106 (as defined by its major curve) has contracted compared to its cross-sectional diameter in the foremost position, so that there is now a divergence between the cross-sectional diameter of the throat of the sleeve 106 and the cross-sectional area of ​​the outlet 102. This contraction of the throat of the sleeve 106, and therefore this divergence between the throat of the sleeve 106 and the outlet 102, first occurs when the sleeve 106 begins to move aftwardly from its foremost position toward the aft end of the nacelle 104. When the sleeve 106 reaches its aftmost position, the divergence between the throat of the sleeve 106 and the outlet 102 reaches its maximum magnitude. Thus, Fig.19The configuration shown in FIG. 1 is referred to herein as a maximum convergence-divergence configuration and comprises a configuration in which the area ratio between the cross-sectional area at the outlet 102 and the main curve (i.e., the throat of the sleeve 106) is of the maximum magnitude that can be achieved by guiding each sleeve segment 108. This maximum convergence-divergence configuration generates a high speed supersonic flow at the outlet 102 and is well suited for sustained supersonic flight of the aircraft 30.

[0086] Continue to refer Figure 1-Figure 19 , Fig. 20 1 is a cross-sectional view showing a guide 110 of the nozzle assembly 100. In the illustrated embodiment, the guide 110 is composed of a front track 112 and a rear track 114. The front track 112 and the rear track 114 are coupled to the nacelle 104 and are configured to guide each sleeve segment 108 when the sleeve 106 moves between its forward-most position and its rearward position. The front track 112 and the rear track 114 are both generally parallel to the inner surface of the nacelle 104. The front portion of the sleeve segment 108 is equipped with a track follower 116 that is configured to travel within the front track 112 to guide the front end of the sleeve segment 108 as the sleeve segment 108 moves forward and backward. Similarly, the rear portion of the sleeve segment 108 is equipped with a track follower 118 that is configured to travel within the rear track 114 to guide the rear end of the sleeve segment 108 as the sleeve segment 108 moves forward and backward. Because the front rails 112 and the rear rails 114 are parallel and arranged in series, the front and rear ends of the sleeve section 108 do not move inwardly or outwardly relative to each other when the sleeve 106 moves between the forward-most position and the rearward-most position. As the sleeve 106 moves forwardly and rearwardly within the nacelle 104, the sleeve 106 expands and contracts, respectively, due to the profile of the nacelle 104. This creates a path with a variable throat through the sleeve 106 and through the nacelle 104. This, in turn, creates a selectively controllable mass flow rate that varies corresponding to the position of the sleeve 106 within the nacelle 104.

[0087] Continue to refer Figure 1-Figure 20 , Fig.21 and Fig. 22 106 are partially cutaway cross-sectional views showing a portion of the nozzle assembly 100 as the sleeve 106 moves from the forward position to the rearward position within the nacelle 104. These views respectively show the movement of the sleeve 106 as the sleeve 106 moves from the forward position to the rearward position. Fig.21 The front position and Fig. 22 The continuous converging paths and the maximum converging-diverging paths generated by the final position of

[0088] Fig.21The nozzle assembly 100 is shown with the sleeve 106 disposed in a forward-most position. In this view, the main curve 120 of the sleeve segment 108 can be best seen. The portion of the sleeve segment 108 forward of the main curve 120 diverges in an upstream direction, and the portion of the sleeve 108 downstream of the main curve 120 diverges in a downstream direction. When the sleeve 106 is disposed in its forward-most position within the nacelle 104, the narrowest cross-sectional area of ​​the sleeve 106, as defined by the main curve 120, has a cross-sectional dimension that is greater than the cross-sectional area of ​​the outlet 102. Thus, when the sleeve 106 is disposed in the forward-most position, the throat (A8) of the nozzle assembly 108 is juxtaposed with the outlet plane (A9) of the nozzle assembly 108. This produces a mass flow that remains subsonic as it travels through the nozzle assembly 100. This subsonic flow is well suited for the takeoff and landing phases of flight. Furthermore, because the subsonic flow approaches transonic speeds, Fig.21 The configuration shown in is also well suited for the transonic phase of flight.

[0089] Fig. 22 The nozzle assembly 100 is shown with the sleeve 106 disposed in the forward most position, wherein the sleeve 106 is retracted to the greatest extent possible. The cross-sectional area of ​​the sleeve 106 at the main curve 120 is now at its smallest possible amplitude. Accordingly, the throat (A8) of the nozzle assembly 100 is now located at the main curve 120. The portion of each sleeve segment 108 upstream of the main curve 120 converges in the downstream direction, and the portion of the sleeve segment 108 downstream of the main curve 120 diverges in the downstream direction, thereby producing a converging-diverging configuration of the sleeve 106 and the nozzle assembly 100, allowing the mass flow to reach supersonic speeds at the outlet 102. Therefore, this configuration is very suitable for the supersonic flight stage.

[0090] The above discussion about the plurality of seals 90, the plurality of seals 92, and the plurality of seals 94 relative to the nozzle assembly 60 is applied to the nozzle assembly 100 with equal force and to the same extent. For the sake of brevity, this discussion will not be repeated here. In other embodiments of the nozzle assembly disclosed herein, any other suitable seal or seals that are effective in inhibiting mass flow leakage as the mass flow moves through the nozzle assembly may be used without departing from the teachings of the present disclosure.

[0091] Continue to refer Figure 1-Figure 22 , Fig.23 1 is a partially cut-away perspective view of an actuator 130 suitable for use with nozzle assembly 60, nozzle assembly 100, and any other nozzle assembly made according to the teachings disclosed herein. Actuator 130 is configured to move sleeve 66, sleeve 106, or any other sleeve made according to the teachings disclosed herein between various longitudinal positions within nacelle 62 and nacelle 102, as described above.

[0092] In the illustrated embodiment, the actuator 130 includes a plurality of ball screw drives. However, it should be understood that any actuator that effectively moves the sleeve 66, the sleeve 106, or any other sleeve made according to the teachings disclosed herein may be employed without departing from the teachings of the present disclosure. Each ball screw drive receives torque from a segmented flexible shaft 132 that extends around the entire circumference of the nozzle assembly. By using a single torque source to drive each individual ball screw drive, each ball screw drive will move in unison with each other.

[0093] Although at least one exemplary embodiment has been presented in the foregoing detailed description of the present disclosure, it should be understood that there are a large number of variations. It should also be understood that the exemplary embodiment or multiple exemplary embodiments are merely examples and are not intended to limit the scope, applicability or configuration of the present invention in any way. On the contrary, the foregoing detailed description will provide a convenient roadmap for implementing the exemplary embodiments of the present invention to those skilled in the art. It should be understood that various changes may be made to the functions and arrangements of the elements described in the exemplary embodiments without departing from the scope of the present disclosure as set forth in the appended claims.

Claims

1. A nozzle assembly for use with a propulsion system of an aircraft, the propulsion system comprising an engine, the engine being configured to produce a mass flow, the nozzle assembly comprising: Nacelle; a sleeve mounted within the nacelle downstream of the engine, the sleeve being configured to move between a forward position and an aft position within the nacelle and further configured to receive the mass flow from the engine and direct the mass flow to an outlet of the propulsion system, the sleeve comprising a plurality of sleeve segments, each of the plurality of sleeve segments being longitudinally aligned and disposed in a circumferential arrangement to form the sleeve; a plurality of guides, each guide of the plurality of guides coupled to a sleeve segment of the plurality of sleeve segments, each guide configured to guide movement of each sleeve segment as the sleeve moves between the forward position and the rearward position; as well as an actuator coupled to the sleeve and configured to move the sleeve between the forward position and the rearward position; wherein the inner surfaces of each sleeve segment cooperate with each other to define a path for directing the mass flow through the sleeve, wherein a circumferential distance between a portion of each sleeve segment varies as the sleeve moves between the forward position and the rearward position, wherein the path, together with an inner surface of the nacelle, has a longitudinal profile that changes as the sleeve moves between the forward position and the aft position; and wherein the path has a transverse cross-sectional area that varies as the sleeve moves between the forward position and the rearward position.

2. The nozzle assembly according to claim 1, wherein: Each sleeve segment has the same plan shape.

3. The nozzle assembly according to claim 1, wherein: The plurality of guides includes a plurality of tracks, and wherein the nozzle assembly further includes a plurality of track followers, each track follower of the plurality of track followers coupled to a corresponding track at a first end and coupled to a sleeve segment at a second end.

4. The nozzle assembly according to claim 3, wherein: The plurality of guides are coupled to the inner surface of the nacelle.

5. The nozzle assembly according to claim 3, wherein: Each sleeve segment is coupled to two of the rail followers.

6. The nozzle assembly according to claim 5, wherein: The two track followers are coupled to the sleeve segment at longitudinally spaced locations.

7. The nozzle assembly of claim 1, further comprising a plurality of sealing members, each of the plurality of sealing members being disposed in a position to inhibit leakage of the mass flow between two adjacent sleeve segments.

8. The nozzle assembly of claim 1, further comprising a plurality of sealing members, each of the plurality of sealing members being disposed in a position to inhibit leakage of the mass flow between the sleeve and an inner mold line of the nacelle.

9. The nozzle assembly of claim 1, further comprising a plurality of sealing members, each of the plurality of sealing members being disposed in a position to inhibit leakage of the mass flow into the plurality of guides.

10. The nozzle assembly of claim 1, wherein: Each sleeve segment has a profile comprising a main curve which projects inwardly towards the centre of the circumferential arrangement, all of the main curves together forming the narrowest cross-sectional area of ​​the sleeve.

11. The nozzle assembly of claim 10, further comprising a controller operably coupled to the actuator and configured to control the actuator to move the sleeve to a longitudinal position within the nacelle, the longitudinal position causing the sleeve, together with the inner surface of the nacelle, to have a longitudinal configuration corresponding to a flight stage of the aircraft.

12. The nozzle assembly according to claim 11, wherein: The controller is configured to control the actuator to move the sleeve to a longitudinal position within the nacelle, wherein the sleeve, together with the inner surface of the nacelle, has a longitudinal cross-sectional configuration that continuously converges between the narrowest cross-sectional area of ​​the sleeve and the outlet when the aircraft is in takeoff and landing phases of flight.

13. The nozzle assembly of claim 11, wherein: The controller is configured to control the actuator to move the sleeve to a longitudinal position within the nacelle, wherein the sleeve together with the inner surface of the nacelle has a longitudinal cross-sectional configuration having a minimum convergence-divergence configuration when the aircraft is in a transonic flight phase.

14. The nozzle assembly of claim 11, wherein: The controller is configured to control the actuator to move the sleeve to a longitudinal position within the nacelle, wherein the sleeve together with an inner surface of the nacelle has a longitudinal cross-sectional configuration having a maximum convergence-divergence configuration when the aircraft is in a supersonic flight phase.

15. A nozzle assembly for use with a propulsion system of an aircraft, the propulsion system comprising an engine, the engine being configured to produce a mass flow, the nozzle assembly comprising: Nacelle; a sleeve mounted within the nacelle downstream of the engine, the sleeve being configured to move between a forward position and an aft position within the nacelle and further configured to receive the mass flow from the engine and direct the mass flow to an outlet of the propulsion system, the sleeve comprising a plurality of sleeve segments, each of the plurality of sleeve segments being longitudinally aligned and disposed in a circumferential arrangement to form the sleeve; a plurality of guides, each guide of the plurality of guides coupled to a sleeve segment of the plurality of sleeve segments, each guide configured to guide movement of each sleeve segment as the sleeve moves between the forward position and the rearward position; as well as an actuator coupled to the sleeve and configured to move the sleeve between the forward position and the rearward position; wherein the inner surfaces of each sleeve segment cooperate with each other to define a path for directing the mass flow through the sleeve, wherein a circumferential distance between a portion of each sleeve segment varies as the sleeve moves between the forward position and the rearward position, wherein the path together with the inner surface of the nacelle has a longitudinal profile that changes as the sleeve moves between the forward position and the aft position; wherein the path has a transverse cross-sectional area that varies as the sleeve moves between the forward position and the rearward position, Wherein, the plurality of guides are configured to guide a front portion of each sleeve segment in a first direction and to guide a rear portion of each sleeve segment in a second direction.

16. The nozzle assembly of claim 15, wherein: The rearward end of the sleeve includes the outlet of the propulsion system, and wherein the cross-sectional area of ​​the rearward end of the sleeve changes as the sleeve moves in an upstream direction from the rearward position.

17. The nozzle assembly of claim 15, wherein: The sleeve together with the inner surface of the nacelle has a continuously converging longitudinal cross-sectional configuration when the sleeve is in the aft position and a maximum converging-diverging longitudinal cross-sectional configuration when the sleeve is in the forward position.

18. The nozzle assembly of claim 17, wherein: The multiple guides are configured to guide the front portion of each sleeve segment circumferentially inward along a first direction when the sleeve moves from the rear position to the front position, so that a first distance between the front portions of each adjacent sleeve segment decreases, and to guide the rear portion of each sleeve segment circumferentially inward along a second direction when the sleeve moves from the rear position to the front position, so that a second distance between the rear portions of each adjacent sleeve segment increases.

19. The nozzle assembly of claim 15, further comprising a controller operably coupled to the actuator and configured to control the actuator.

20. The nozzle assembly of claim 15, wherein: When the sleeve is in the rearward position, the rearward end of the sleeve protrudes beyond the rearward end of the nacelle.

21. A nozzle assembly for use with a propulsion system of an aircraft, the propulsion system comprising an engine, the engine being configured to produce a mass flow, the nozzle assembly comprising: Nacelle; a sleeve mounted within the nacelle downstream of the engine, the sleeve being configured to move between a forward position and an aft position within the nacelle and further configured to receive the mass flow from the engine and direct the mass flow to an outlet of the propulsion system, the sleeve comprising a plurality of sleeve segments, each of the plurality of sleeve segments being longitudinally aligned and disposed in a circumferential arrangement to form the sleeve; a plurality of guides, each guide of the plurality of guides coupled to a sleeve segment of the plurality of sleeve segments, each guide configured to guide movement of each sleeve segment as the sleeve moves between the forward position and the rearward position; as well as an actuator coupled to the sleeve and configured to move the sleeve between the forward position and the rearward position, wherein the inner surfaces of each sleeve segment cooperate with each other to define a path for directing the mass flow through the sleeve, wherein a circumferential distance between a portion of each sleeve segment varies as the sleeve moves between the forward position and the rearward position, wherein the path together with the inner surface of the nacelle has a longitudinal profile that changes as the sleeve moves between the forward position and the aft position; wherein the path has a transverse cross-sectional area that varies as the sleeve moves between the forward position and the rearward position, Wherein, the plurality of guides are configured to guide a front portion of each sleeve segment and a rear portion of each sleeve segment in parallel directions.

22. The nozzle assembly of claim 21, further comprising a controller operably coupled to the actuator and configured to control the actuator.

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