The present disclosure relates to gas turbine engine mounts.
Aircraft may be powered by one or more gas turbine engines. The engine(s) may be mounted to the aircraft via one or more engine frames configured to interlock or couple to a pylon or other mounting feature of the aircraft structure.
A full and enabling disclosure of the present disclosure, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which:
Reference will now be made in detail to present embodiments of the disclosure, one or more examples of which are illustrated in the accompanying drawings. The detailed description uses numerical and letter designations to refer to features in the drawings. Like or similar designations in the drawings and description have been used to refer to like or similar parts of the disclosure.
The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any implementation described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other implementations. Additionally, unless specifically identified otherwise, all embodiments described herein should be considered exemplary.
As used herein, the terms “first”, “second”, and “third” may be used interchangeably to distinguish one component from another and are not intended to signify location or importance of the individual components.
The terms “forward” and “aft” refer to relative positions within a gas turbine engine or aircraft and refer to the normal operational attitude of the gas turbine engine or aircraft. For example, with regards to a gas turbine engine, forward refers to a position closer to an engine inlet and aft refers to a position closer to an engine nozzle or exhaust.
The terms “upstream” and “downstream” refer to the relative direction with respect to fluid flow in a fluid pathway. For example, “upstream” refers to the direction from which the fluid flows, and “downstream” refers to the direction to which the fluid flows.
The terms “coupled,” “fixed,” “attached to,” and the like refer to both direct coupling, fixing, or attaching, as well as indirect coupling, fixing, or attaching through one or more intermediate components or features, unless otherwise specified herein.
The singular forms “a”, “an”, and “the” include plural references unless the context clearly dictates otherwise.
Here and throughout the specification and claims, range limitations are combined and interchanged, such ranges are identified and include all the sub-ranges contained therein unless context or language indicates otherwise. For example, all ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other.
A “third stream” as used herein means a non-primary air stream capable of increasing fluid energy to produce a minority of total propulsion system thrust. A pressure ratio of the third stream may be higher than that of the primary propulsion stream (e.g., a bypass or propeller driven propulsion stream). The thrust may be produced through a dedicated nozzle or through mixing of an airflow through the third stream with a primary propulsion stream or a core air stream, e.g., into a common nozzle.
Generally, exhaust flowing from an open fan prop or unducted primary fan of a turbofan engine is sonic or even supersonic at climb and cruise conditions. This high-speed exhaust flow scrubs across or by the nacelle and pylon fairing. For sonic and supersonic flow around the nacelle and pylon fairing, shocks and shock losses are expected and can result in a considerable penalty to aircraft-level performance such as fuel burn rate and drag. Engine mounts are a key constraint on the nacelle flow path and depressing the engine mounts into an engine's frame, particularly the forward frame, enables a smoother, lower profile, more continuous curvature flow path around the engine nacelle and any local fairings around the engine mounts. The design disclosed herein reduces total drag, peak Mach numbers occurring on the nacelle and/or pylon, and therefore the risk of wave drag.
Referring now to the drawings,
For reference, the engine 100 defines an axial direction A, a radial direction R, and a circumferential direction C. Moreover, the engine 100 defines an axial centerline or longitudinal axis 102 that extends along the axial direction A. In general, the axial direction A extends parallel to the longitudinal axis 102, the radial direction R extends outward from and inward to the longitudinal axis 102 in a direction orthogonal to the axial direction A, and the circumferential direction extends three hundred sixty degrees (360°) around the longitudinal axis 102. The engine 100 extends between a forward end 104 and an aft end 106, e.g., along the axial direction A.
As shown in
It will be appreciated that as used herein, the terms “high/low speed” and “high/low-pressure” are used with respect to the high-pressure/high speed system and low-pressure/low speed system interchangeably. Further, it will be appreciated that the terms “high” and “low” are used in this same context to distinguish the two systems and are not meant to imply any absolute speed and/or pressure values.
The high energy combustion products flow from the combustor 118 downstream to a high-pressure turbine 120. The high-pressure turbine 120 drives the high-pressure compressor 116 through a high-pressure shaft 124. In this regard, the high-pressure turbine 120 is drivingly coupled with the high-pressure compressor 116. The high energy combustion products then flow to a low-pressure turbine 122. The low-pressure turbine 122 drives the low-pressure compressor 114 and components of the fan section 136 through a low-pressure shaft 126. In this regard, the low-pressure turbine 122 is drivingly coupled with the low-pressure compressor 114 and components of the fan section 136. The low-pressure shaft 126 is coaxial with the high-pressure shaft 124 in this example embodiment. After driving each of the high-pressure turbine 120 and the low-pressure turbine 122, the combustion products exit the turbomachine 108 through a turbomachine exhaust nozzle 128. A core engine 134 of the gas turbine engine 100 is defined as the part of the gas turbine engine 100 that extends from the fan blades 140 of the fan section 136 to the turbomachine exhaust nozzle 128.
Accordingly, the turbomachine 108 defines a working gas flowpath or core duct 130 that extends between the core inlet 112 and the turbomachine exhaust nozzle 128. The core duct 130 is an annular duct positioned generally inward of the core cowl 110 along the radial direction R. The core duct 130 (e.g., the working gas flowpath through the turbomachine 108) may be referred to as a second stream. The fan section 136 includes a fan 138, which is the primary fan in this example embodiment. For the depicted embodiment of
As depicted, the fan 138 includes a plurality or an array of fan blades 140 (only one shown in
Moreover, the array of fan blades 140 can be arranged in equal spacing around the longitudinal axis 102. Each fan blade 140 has a root and a tip and a span defined therebetween. Each fan blade 140 defines a central blade axis 144. For this embodiment, each fan blade 140 of the fan 138 is rotatable about its central blade axis 144, e.g., in unison with one another. One or more actuators 146 are provided to facilitate such rotation and therefore may be used to change a pitch of the fan blades 140 about their respective central blades' axes 144.
The fan section 136 further includes a fan guide vane array 148 that includes fan guide vanes 150 (only one shown in
Each fan guide vane 150 defines a central blade axis 152. For this embodiment, each fan guide vane 150 of the fan guide vane array 148 is rotatable about its respective central blade axis 152, e.g., in unison with one another. One or more actuators 154 are provided to facilitate such rotation and therefore may be used to change a pitch of the fan guide vane 150 about its respective central blade axis 152. However, in other embodiments, each fan guide vane 150 may be fixed or unable to be pitched about its central blade axis 152. The fan guide vanes 150 are mounted to a fan cowl 156.
As shown in
The ducted fan 170 includes a plurality of fan blades (not separately labeled in
The fan cowl 156 annularly encases at least a portion of the core cowl 110 and is generally positioned outward of at least a portion of the core cowl 110 along the radial direction R. Particularly, a downstream section of the fan cowl 156 extends over a forward portion of the core cowl 110 to define a fan duct flowpath, or simply a fan duct 158. According to this embodiment, the fan flowpath or fan duct 158 may be understood as forming at least a portion of the third stream of the engine 100.
Incoming air may enter through the fan duct 158 through a fan duct inlet 162 and may exit through a fan exhaust nozzle 164 to produce propulsive thrust. The fan duct 158 is an annular duct positioned generally outward of the core duct 130 along the radial direction R. The fan cowl 156 and the core cowl 110 are connected together and supported by a plurality of substantially radially extending and circumferentially spaced stationary struts 160 (only one shown in
The stationary struts 160 may each be aerodynamically contoured to direct air flowing thereby. Other struts in addition to the stationary struts 160 may be used to connect and support the fan cowl 156 and/or core cowl 110. In many embodiments, the fan duct 158 and the core duct 130 may at least partially co-extend (generally axially) on opposite sides (e.g., opposite radial sides) of the core cowl 110. For example, the fan duct 158 and the core duct 130 may each extend directly from a leading edge 132 of the core cowl 110 and may partially co-extend generally axially on opposite radial sides of the core cowl 110.
The exemplary engine 100 shown in
Notably, for the embodiment depicted, the engine 100 includes one or more features to increase an efficiency of a third-stream thrust, Fn3S (e.g., a thrust generated by an airflow through the fan duct 158 exiting through the fan exhaust nozzle 164, generated at least in part by the ducted fan 170). In particular, the engine 100 further includes an array of inlet guide vanes 172 positioned in the inlet duct 166 upstream of the ducted fan 170 and downstream of the engine inlet 168. The array of inlet guide vanes 172 are arranged around the longitudinal axis 102. For this embodiment, the inlet guide vanes 172 are not rotatable about the longitudinal axis 102.
Each inlet guide vane 172 defines a central blade axis (not labeled for clarity), and is rotatable about its respective central blade axis, e.g., in unison with one another. In such a manner, the inlet guide vanes 172 may be considered a variable geometry component. One or more actuators 174 are provided to facilitate such rotation and therefore may be used to change a pitch of the inlet guide vanes 172 about their respective central blade axes. However, in other embodiments, each inlet guide vanes 172 may be fixed or unable to be pitched about its central blade axis.
Further, located downstream of the ducted fan 170 and upstream of the fan duct inlet 162, the engine 100 includes an array of outlet guide vanes 176. As with the array of inlet guide vanes 172, the array of outlet guide vanes 176 are not rotatable about the longitudinal axis 102. However, for the embodiment depicted, unlike the array of inlet guide vanes 172, the array of outlet guide vanes 176 are configured as fixed-pitch outlet guide vanes.
Further, it will be appreciated that for the embodiment depicted, the fan exhaust nozzle 164 of the fan duct 158 is further configured as a variable geometry exhaust nozzle. In such a manner, the engine 100 includes one or more actuators 178 for modulating the variable geometry exhaust nozzle. For example, the variable geometry exhaust nozzle may be configured to vary a total cross-sectional area (e.g., an area of the nozzle in a plane perpendicular to the longitudinal axis 102) to modulate an amount of thrust generated based on one or more engine operating conditions (e.g., temperature, pressure, mass flowrate, etc. of an airflow through the fan duct 158). A fixed geometry exhaust nozzle may also be adopted.
The combination of the array of inlet guide vanes 172 located upstream of the ducted fan 170, the array of outlet guide vanes 176 located downstream of the ducted fan 170, and the fan exhaust nozzle 164 may result in a more efficient generation of third-stream thrust, Fn3S, during one or more engine operating conditions. Further, by introducing a variability in the geometry of the inlet guide vanes 172 and the fan exhaust nozzle 164, the engine 100 may be capable of generating more efficient third-stream thrust, Fn3S, across a relatively wide array of engine operating conditions, including takeoff and climb (where a maximum total engine thrust FnTotal, is generally needed) as well as cruise (where a lesser amount of total engine thrust, FnTotal, is generally needed).
Moreover, referring still to
Although not depicted in detail, the heat exchanger 180 may be an annular heat exchanger extending substantially 360 degrees in the fan duct 158 (e.g., at least 300 degrees, such as at least 330 degrees). In such a manner, the heat exchanger 180 may effectively utilize the air passing through the fan duct 158 to cool one or more systems of the engine 100 (e.g., lubrication oil systems, compressor bleed air, electrical components, etc.). The heat exchanger 180 uses the air passing through duct 158 as a heat sink and correspondingly increases the temperature of the air downstream of the heat exchanger 180 and exiting the fan exhaust nozzle 164.
Although depicted above as an unshrouded or open rotor engine in the embodiments depicted above, it should be appreciated that aspects of the disclosure provided herein may be applied to shrouded or ducted engines, partially ducted engines, aft-fan engines, or other gas turbine engine configurations, including those for marine, industrial, or aero-propulsion systems. Certain aspects of the disclosure may be applicable to turbofan, turboprop, or turboshaft engines.
In certain configurations, the engine 100 may further include a thrust link or linkage 190 that transmits axial, engine thrust loads between the engine 100 and the pylon 22 and/or the airframe of the aircraft 10 shown in
In exemplary embodiments, as shown in
In exemplary embodiments, as shown in
As shown in
In exemplary embodiments, as shown in
In exemplary embodiments, as shown in
In particular embodiments, as shown in
In particular embodiments, as shown in
It is to be appreciated that although it is not illustrated in the figures, the forward frame 200 may include more than two indentions each with respective engine mount flanges depending on the mounting configuration/requirements of a particular engine design. Although not shown, it is also to be appreciated that the gas turbine engine 100 may include two or more forward frames which includes one or more indentions as described above and as shown in
As previously mentioned, engine mounts are a key constraint on the nacelle flow path and depressing the engine mounts into an engine's frame in the manner described and claimed herein, particularly the forward frame, enables a smoother, lower profile, more continuous curvature flow path around the engine nacelle and any local fairings around the engine mounts. More particularly, the design disclosed herein reduces total drag, peak Mach numbers occurring on the nacelle and/or pylon, and therefore the risk of wave drag.
This written description uses examples to disclose the present disclosure, including the best mode, and to enable any person skilled in the art to practice the disclosure, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the disclosure is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.
Further aspects are provided by the subject matter of the following clauses:
A gas turbine engine comprising: an aft frame, and a forward frame disposed upstream from the aft frame. The forward frame including an outer ring, wherein the outer ring includes an inner surface radially spaced from an outer surface, a first indention defined in the outer surface, and a first engine mount flange protruding radially outwardly from the first indention.
The gas turbine engine of the preceding clause, wherein the gas turbine engine has an unducted primary fan.
The gas turbine engine of any preceding clause, wherein gas turbine engine is a three-stream gas turbine engine.
The gas turbine engine of any preceding clause, wherein the forward frame further comprises an inner ring including an outer surface circumferentially surrounded by the outer ring, wherein a flow channel is defined between the outer surface of the inner ring and the inner surface of the outer ring.
The gas turbine engine of any preceding clause, wherein the forward frame includes an upstream end axially spaced from a downstream end, wherein the flow channel converges between the upstream end and the downstream end.
The gas turbine engine of any preceding clause, wherein the inner surface of the outer ring at the first indention extends radially inward into the flow channel.
The gas turbine engine of any preceding clause, wherein the forward frame further comprises a plurality of struts that extend radially from the outer surface of the inner ring to the inner surface of the outer ring within the flow channel.
The gas turbine engine of any preceding clause, wherein the inner surface of the outer ring at the first indention extends radially inward into the flow channel at opposing sides of a strut of the plurality of struts.
The gas turbine engine of any preceding clause, wherein the outer ring further includes a second indention defined along the outer surface of the outer ring and a second engine mount flange protruding radially outwardly from the second indention.
The gas turbine engine of any preceding clause, wherein the second indention and the second engine mount are circumferentially spaced from the first indention and the first engine mount flange.
The gas turbine engine of any preceding clause, wherein the forward frame further comprises an inner ring including an outer surface circumferentially surrounded by the outer ring, wherein a flow channel is defined between the outer surface of the inner ring and the inner surface of the outer ring, and wherein the inner surface of the outer ring at the first indention and at the second indention extends radially inward into the flow channel.
The gas turbine engine of any preceding clause, wherein the forward frame further comprises a plurality of struts that extend radially from the outer surface of the inner ring to the inner surface of the outer ring within the flow channel, wherein the inner surface of the outer ring at the first indention extends radially inward into the flow channel at opposing sides of a first strut of the plurality of struts, and the second indention extends radially inward into the flow channel at opposing sides of a second strut of the plurality of struts.
An aircraft, comprising: a wing including a mounting pylon; and a gas turbine engine. The gas turbine engine comprising: a forward frame including an outer ring, wherein the outer ring includes an inner surface that is radially spaced from an outer surface, a first indention defined in the outer surface, and a first engine mount flange protruding radially outwardly from the first indention, wherein the first engine mount flange is coupled to the pylon.
The aircraft of the preceding clause, wherein the gas turbine engine has an unducted primary fan.
The aircraft of any preceding clause, wherein gas turbine engine is a three-stream gas turbine engine.
The aircraft of any preceding clause, wherein the forward frame further comprises an inner ring including an outer surface circumferentially surrounded by the outer ring, wherein a flow channel is defined between the outer surface of the inner ring and the inner surface of the outer ring.
The aircraft of any preceding clause, wherein the forward frame includes an upstream end axially spaced from a downstream end, wherein the flow channel converges between the upstream end and the downstream end.
The aircraft of any preceding clause, wherein the inner surface of the outer ring at the first indention extends radially inward into the flow channel.
The aircraft of any preceding clause, wherein the forward frame further comprises a plurality of struts that extend radially from the outer surface of the inner ring to the inner surface of the outer ring within the flow channel, wherein the inner surface of the outer ring at the first indention extends radially inward into the flow channel at opposing sides of a strut of the plurality of struts.
The aircraft of any preceding clause, wherein the outer ring further includes a second indention defined along the outer surface of the outer ring and a second engine mount flange protruding radially outwardly from the second indention, wherein the second indention and the second engine mount flange are circumferentially spaced from the first indention and the first engine mount flange, wherein the inner surface of the outer ring at the first indention and at the second indention extends radially inward into the flow channel.