Patent Grant
11686211
The present disclosure relates generally to gas turbine engines, and more specifically to fan assemblies of gas turbine engines.
Gas turbine engines are used to power aircraft, watercraft, power generators, and the like. Gas turbine engines typically include an engine core having a compressor, a combustor, and a turbine. The compressor compresses air drawn into the engine and delivers high pressure air to the combustor. In the combustor, fuel is mixed with the high pressure air and is ignited. Products of the combustion reaction in the combustor are directed into the turbine where work is extracted to drive the compressor and, sometimes, an output shaft. Left-over products of the combustion are exhausted out of the turbine and may provide thrust in some applications.
Gas turbine engines also typically include a fan positioned within an inlet duct of the gas turbine engine. The fan includes rotating blades that that force air into the compressor section of the engine, as well as potentially providing additional thrust via forcing air around the engine core through bypass ducts. The fan blades may experience various operability issues due to factors such as variations in the intake airflow and pressure fluctuations within the inlet and the bypass ducts.
The present disclosure may comprise one or more of the following features and combinations thereof.
A fan assembly for a gas turbine engine according to the present disclosure includes a fan duct arranged circumferentially around a central axis, an inlet fan, and an outlet guide vane assembly. The fan duct is arranged circumferentially around a central axis. The inlet fan includes a plurality of fan blades that extend radially outward relative to the central axis and that are adapted to rotate about the central axis to force fan exit air toward an aft end of the fan duct.
The outlet guide vane assembly is located in the fan duct axially downstream of the inlet fan and configured to adjust a direction of the fan exit air received from the plurality of fan blades. The outlet guide vane assembly includes a plurality of variable-pitch outlet guide vanes including a first variable-pitch outlet guide vane that extends radially relative to the central axis and a plurality of actuation assemblies including a first actuation assembly connected to the first variable-pitch outlet guide vane and configured to control rotation of the first variable-pitch outlet guide vane about a leading edge pitch axis that extends radially from the central axis, the first variable-pitch outlet guide vane having a leading edge portion configured to rotate about the leading edge pitch axis and a trailing edge portion rotatably coupled to an axially aft edge of the leading edge portion and configured to rotate relative to the leading edge portion about a trailing edge pitch axis that is parallel to the leading edge pitch axis.
In some embodiments, the first actuation assembly is configured to rotate the leading edge portion and the trailing edge portion of the first variable-pitch outlet guide vane to a first arrangement in which the leading edge portion is at a first leading edge angle in response to the gas turbine engine operating at a given operating condition so as to redirect the fan exit air in a first direction and the trailing edge portion is at a first trailing edge angle relative to the leading edge portion in order to redirect the fan exit air flowing in the first direction in a second direction to minimize losses created by distortions in fan inlet air and created by the leading edge portion redirecting the fan exit air in the first direction.
In some embodiments, the fan assembly further includes a control system operably connected to the plurality of actuation assemblies and configured to rotate the leading edge portion and the trailing edge portion of the first variable-pitch outlet guide vane via the first actuation assembly. The control system is configured to rotate the leading edge portion and the trailing edge portion such that the first direction is different than the second direction.
In some embodiments, the second direction is parallel with the central axis such that the fan exit air exiting the trailing edge portion of the first variable-pitch outlet guide vane returns to an axial flow after passing over the outlet guide vane assembly.
In some embodiments, the first actuation assembly includes a first actuator connected to the leading edge portion, and the first actuator is configured to rotate the leading edge portion about the leading edge pitch axis.
In some embodiments, the leading edge portion of the first variable-pitch outlet guide vane includes a radially extending leading edge portion trim cavity that opens at a radially outer end of the leading edge portion, the first actuation assembly further includes a second actuator and a control rod connected to the second actuator and extending radially inwardly into the leading edge portion trim cavity of the leading edge portion, and the control rod is coaxial with the leading edge pitch axis of the leading edge portion.
In some embodiments, the first actuation assembly further includes a cam coupled to a portion of the control rod located within the leading edge portion trim cavity of the leading edge portion and a cam rod having a first end and an opposite second end, the first end of the cam rod is configured to operatively engage the cam and the second end is rotatably coupled to the trailing edge portion of the first variable-pitch outlet guide vane.
In some embodiments, the second actuator is configured to rotate the control rod so as to rotate the cam, and the rotation of the cam moves the cam rod in an axial direction such that the cam rod rotates the trailing edge portion of the first variable-pitch outlet guide vane about the trailing edge pitch axis.
In some embodiments, the first variable-pitch outlet guide vane further includes a vane stem extending between and connected to the radially outer end of the leading edge portion and to the first actuator. The first actuator is configured to rotate the vane stem so as to rotate the leading edge portion. The vane stem includes a vane stem trim cavity coaxial with the leading edge portion trim cavity. The control rod extends through the vane stem trim cavity and the leading edge portion trim cavity.
In some embodiments, the first variable-pitch outlet guide vane includes a hinge rod coupling the leading edge portion to the trailing edge portion.
In some embodiments, the control system is further configured to at least one of (i) rotate the leading edge portion of each variable-pitch outlet guide vane of the plurality of variable-pitch outlet guide vanes individually relative to the other leading edge portions of the plurality of variable-pitch outlet guide vanes and (ii) rotate the trailing edge portion of each variable-pitch outlet guide vane of the plurality of variable-pitch outlet guide vanes individually relative to the other trailing edge portions of the plurality of variable-pitch outlet guide vanes.
In some embodiments, the control system is configured to rotate the leading edge portion of each variable-pitch outlet guide vane of the plurality of variable-pitch outlet guide vanes individually and to rotate the trailing edge portion of each variable-pitch outlet guide vane of the plurality of variable-pitch outlet guide vanes individually.
In some embodiments, the plurality of variable-pitch outlet guide vanes includes a second variable-pitch outlet guide vane different from the first variable-pitch outlet guide vane. The control system is configured to rotate the leading edge portion of the second variable-pitch outlet guide vane to a second leading edge portion angle that is different than the first leading edge portion angle, and to rotate the trailing edge portion of the second variable-pitch outlet guide vane to a second trailing edge portion angle that is different than the first trailing edge portion angle.
In some embodiments, the plurality of variable-pitch outlet guide vanes includes a first group of leading edge portions and a second group of leading edge portions different from the first group of first variable-pitch outlet guide vanes. The plurality of variable-pitch outlet guide vanes further includes a first group of trailing edge portions and a second group of trailing edge portions different from the first group of trailing edge portions. The control system is configured to rotate the first group of leading edge portions to the first leading edge angle and the second group of leading edge portion to a second leading edge angle that is different from the first leading edge angle, and to rotate the first group of trailing edge portions to the first trailing edge angle and the second group of trailing edge portions to a second trailing edge angle that is different from the first trailing edge angle.
In some embodiments, the first group of leading edge portions are ganged to each other and the second group of leading edge portions are ganged to each other. The first group of trailing edge portions are ganged to each other and the second group of trailing edge portions are ganged to each other.
In some embodiments, the control system includes at least one sensor including at least one of a dynamic sensor, a static wall pressure sensor, an altitude sensor, an angle of attack of the plurality of fan blades, an airspeed sensor, and a sensor configured to measure a rotational speed of the fan blades.
According to another aspect of the present disclosure, a fan assembly for a gas turbine engine includes a fan duct, an inlet fan, and an outlet guide vane assembly. The fan duct is arranged circumferentially around a central axis. The inlet fan includes a plurality of fan blades adapted to force fan exit air toward an aft end of the fan duct.
The outlet guide vane assembly is located in the fan duct axially downstream of the inlet fan, the outlet guide vane assembly including a plurality of variable-pitch outlet guide vanes that extend radially relative to the central axis, each first variable-pitch outlet guide vane having a leading edge portion configured to rotate about a leading edge pitch axis and a trailing edge portion rotatably coupled to the leading edge portion and configured to rotate relative to the leading edge portion.
In some embodiments, the leading edge portion and the trailing edge portion of the first variable-pitch outlet guide vane are configured to rotate to a first arrangement in which the leading edge portion is at a first leading edge angle in response to the gas turbine engine operating at a given operating condition and the trailing edge portion is at a first trailing edge angle relative to the leading edge portion in order to minimize losses created by distortions in fan inlet air and created by the leading edge portion redirecting the fan exit air in the first direction.
In some embodiments, the fan assembly further includes a plurality of actuation assemblies each including a first actuation assembly connected to a first variable-pitch outlet guide vane of the first plurality of variable-pitch outlet guide vanes and configured to control rotation of the leading edge portion and the trailing edge portion of the first variable-pitch outlet guide vane.
In some embodiments, the fan assembly further includes a control system operably connected to the plurality of actuation assemblies and configured to rotate the leading edge portion and the trailing edge portion of the first variable-pitch outlet guide vane via the first actuation assembly. The control system is configured to rotate the first variable-pitch outlet guide vane to the first arrangement in which the leading edge portion is at the first leading edge angle so as to redirect the fan exit air in a first direction and the trailing edge portion is at the first trailing edge angle relative to the leading edge portion in order to redirect the fan exit air flowing in the first direction in a second direction, and wherein the control system is configured to rotate the leading edge portion and the trailing edge portion such that the first direction is different than the second direction.
In some embodiments, the second direction is parallel with the central axis such that the fan exit air exiting the trailing edge portion of the first variable-pitch outlet guide vane returns to an axial flow after passing over the outlet guide vane assembly.
A method according to another aspect of the present disclosure includes arranging a fan duct of a fan assembly of a gas turbine engine circumferentially around a central axis, and providing an inlet fan of the fan assembly, the inlet fan comprising a plurality of fan blades that extend radially outward relative to the central axis that are adapted to rotate about the central axis to force fan exit air toward an aft end of the fan duct.
In some embodiments, the method further includes arranging an outlet guide vane assembly in the fan duct axially downstream of the inlet fan, the outlet guide vane assembly being configured to adjust a direction of the fan exit air received from the plurality of fan blades, the outlet guide vane assembly including a plurality of variable-pitch outlet guide vanes including a first variable-pitch outlet guide vane that extends radially relative to the central axis and a plurality of actuation assemblies including a first actuation assembly connected to the first variable-pitch outlet guide vane and configured to control rotation of the first variable-pitch outlet guide vane about a leading edge pitch axis that extends radially from the central axis, the first variable-pitch outlet guide vane having a leading edge portion configured to rotate about the leading edge pitch axis and a trailing edge portion rotatably coupled to an axially aft edge of the leading edge portion and configured to rotate relative to the leading edge portion about a trailing edge pitch axis that is parallel to the leading edge pitch axis.
In some embodiments, the method further includes rotating, via the first actuation assembly, the leading edge portion and the trailing edge portion of the first variable-pitch outlet guide vane to a first arrangement in which the leading edge portion is at a first leading edge angle in response to the gas turbine engine operating at a given operating condition so as to redirect the fan exit air in a first direction and the trailing edge portion is at a first trailing edge angle relative to the leading edge portion in order to redirect the fan exit air flowing in the first direction in a second direction to minimize losses created by distortions in fan inlet air and created by the leading edge portion redirecting the fan exit air in the first direction.
These and other features of the present disclosure will become more apparent from the following description of the illustrative embodiments.
For the purposes of promoting an understanding of the principles of the disclosure, reference will now be made to a number of illustrative embodiments illustrated in the drawings and specific language will be used to describe the same.
An illustrative aerospace gas turbine engine 10 includes a fan assembly 12 and an engine core 13 having a compressor 14, a combustor 16, and a turbine 18, as shown in
The fan assembly 12 includes an inlet fan having a plurality of fan blades 22 that extend radially outward relative to the central axis 11 and that are located in the inlet of the gas turbine engine 10, as shown in
In the illustrative embodiment, the fan assembly 12 further includes outlet guide vane assembly 28 located in the fan duct 20 axially downstream of the plurality of fan blades 22 that is configured to adjust a direction of the fan exit air 15 received from the plurality of fan blades 22, as shown in
The first plurality of variable-pitch outlet guide vanes 30 includes at least one first variable-pitch outlet guide vane 32 that extends radially outward relative to the central axis 11, as shown in
Each first variable-pitch outlet guide vane 32 includes an airfoil shape having a leading edge 34 located at a forward end of the vane 32, a trailing edge 35 axially spaced apart from the leading edge 34 and located at an aft end of the vane 32, a pressure side surface 36 that extends between the leading edge 34 and the trailing edge 35 on one side of the vane 32, and a suction side surface 37 that extends between the leading edge 34 and the trailing edge 35 on an opposite side of the vane 32, as shown in
Each of the variable-pitch outlet guide vanes 32 extends between a root end 38 and a tip end 39, as shown in
Each first variable-pitch outlet guide vane 32 is configured to rotate about the first pitch axis 33, as shown in
The actuation assembly 70 includes at least the first actuator 74 and a first actuator support arm 76, as shown in
The first actuator 74 may be a relatively small hydraulic actuator or an electric motor actuator such as a stepper motor. As will be discussed in detail below, sections or even individual vanes 32 of the first plurality of variable-pitch outlet guide vanes 30 may be selectively controlled by a control system 90, and as such, the size of the actuators in the actuation assembly 70 may be smaller than would be expected for a typical system configured to drive an entire vane row. In some embodiments, the vanes 32 of the first plurality of guide vanes 30 are mechanically connected to each other, as shown in
In some embodiments in which the vanes 32 of the first plurality of variable-pitch outlet guide vanes 30 are mechanically connected to each other, or ganged, the fan assembly 12 may further include a circumferentially extending connector arm 48 that is coupled to vane 32 such that rotation of one of the vanes 32 will rotate the remainder of the vanes 32 of the first plurality of guide vanes 30, as shown in
In the illustrative embodiment, the fan assembly 12 further includes the second plurality of variable-pitch outlet guide vanes 50 located axially downstream of the first plurality of variable-pitch outlet guide vanes 30, as shown in
Each second variable-pitch outlet guide vane 52 includes an airfoil shape having a leading edge 54 located at a forward end of the vane 52, a trailing edge 55 axially spaced apart from the leading edge 54 and located at an aft end of the vane 52, a pressure side surface 56 that extends between the leading edge 54 and the trailing edge 55 on one side of the vane 52, and a suction side surface 57 that extends between the leading edge 54 and the trailing edge 55 on an opposite side of the vane 52, as shown in
Each of the second variable-pitch outlet guide vanes 52 extend between a root end 58 and a tip end 59, as shown in
The vane 52 further includes an outer pivot shaft 61 that extends from the tip end 59 and is coupled to a second actuator 84 of an actuation assembly 70 located within the outer casing 19. The second actuator 84 is configured to rotate the guide vane 52 about a second pivot axis 53. The root end 58 is located adjacent the inner wall 23 and the tip end 59 is located adjacent an inner surface of the outer fan duct casing 19 such that vane 52 influences the air flow of the fan exit air 15 along an entirety of a radial extent of the fan exit air 15 flow path through the fan duct 20. The inner wall 23 of the fan duct and the inner surface of the outer fan duct casing 19 define the radially inner and outer bounds of the flow path of the fan exit air 15.
Each second variable-pitch outlet guide vane 52 is configured to rotate about the second pitch axis 53, as shown in
The actuation assembly 70 includes the second actuator 84 and a second actuator support arm 86 in addition to the first actuator 84 and the second actuator support arm 86, as shown in
The second actuator 84 may be a relatively small hydraulic actuator or an electric motor actuator such as a stepper motor. As will be discussed in detail below, sections or even individual vanes 52 of the second plurality of variable-pitch outlet guide vanes 50 may be selectively controlled by a control system 90, and as such, the size of the actuators in the actuation assembly 70 may be smaller than would be expected for a typical system configured to drive an entire vane row. In some embodiments, the vanes 52 of the second plurality of guide vanes 50 are mechanically connected to each other, as shown in
In some embodiments in which the vanes 52 of the second plurality of variable-pitch outlet guide vanes 50 are mechanically connected to each other, or ganged, the fan assembly 12 may further include a circumferentially extending connector arm 68 that is coupled to vane 52 such that rotation of one of the vanes 52 will rotate the remainder of the vanes 52 of the second plurality of guide vanes 50, as shown in
In the illustrative embodiment, the first plurality of outlet guide vanes 30 includes the same number of vanes 32 around the circumference of the first plurality of outlet guide vanes 30 as the number of vanes 52 of the second plurality of outlet guide vanes 50. In other embodiments, the first plurality of outlet guide vanes 30 includes a greater number of vanes 32 around the circumference of the first plurality of outlet guide vanes 30 than the number of vanes 52 of the second plurality of outlet guide vanes 50. In other embodiments, the first plurality of outlet guide vanes 30 includes a lower number of vanes 32 around the circumference of the first plurality of outlet guide vanes 30 than the number of vanes 52 of the second plurality of outlet guide vanes 50.
The control system 90 is configured to control rotation of the first plurality of variable-pitch outlet guide vanes 30 and the second plurality of variable-pitch outlet guide vanes 50, as shown in
In some embodiments, the control system 90 is configured to rotate each vane 32 of the first plurality of variable-pitch outlet guide vanes 30 to a first vane-pitch angle in response to the gas turbine engine 10 operating at a given operating condition so as to redirect the fan exit air 15 in a first direction. In particular, the operating condition in which the fan assembly 12 and gas turbine engine 10 are operating in may include at least one of take-off, climb, cruise, descent, and landing of an aircraft having the engine 10 equipped. In each of these operating conditions, the plurality of fan blades 22 and/or the outlet vanes 30 of the fan assembly 12 may experience various undesirable operability issues such as forcing, stall, and flutter. For example, the engine 10 may operate in particular speed ranges for each of the operating conditions, and as result, the fan blades 22 may experience greater or lower levels of forcing, stall, and/or flutter in response to the engine 10 operating in particular speed ranges.
In order to compensate for these forces acting on the fan blades 22, the control system 90 is configured to rotate the first plurality of variable-pitch outlet guide vanes 30 to an arrangement of first vane-pitch angles in order to alter the angle of the flow of fan exit air 15 after it exits the fan blades 22. This change in the angle of flow as the fan exit air 15 passes over the first plurality of variable-pitch outlet guide vanes 30 reduces the amount of forcing, stall, and/or flutter experienced by the fan blades 22 and/or the outlet guide vanes 30. Moreover, the control system 90 is configured to reset a desired incidence of air flow into the first plurality of variable-pitch outlet guide vanes 30 in response to swirl in the inlet flow. This, along with the second plurality of variable-pitch outlet guide vanes 50 redirecting the fan exit air 15 to an axial flow, produces an averaging effect that improves engine performance and efficiency.
In order to recover the losses created by flow separation, flow distortions, vortices, and/or swirl, the control system 90 is configured to rotate the second plurality of variable-pitch outlet guide vanes 50 to an arrangement of second vane-pitch angles in order to alter the angle of the flow of fan exit air 15 after it exits the first plurality of variable-pitch outlet guide vanes 30. In the illustrative embodiment, the control system 90 is configured to rotate the vanes 52 of the second plurality of variable-pitch outlet guide vanes 50 to redirect the fan exit air 15 in a second direction different than the first direction such that the fan exit air 15 returns to an axial, uniform flow direction, or as close to axial and uniform as possible given the air flow and operating conditions. This change in the angle of flow as the fan exit air 15 passes over the second plurality of variable-pitch outlet guide vanes 50 further reduces the losses created by inlet flow distortion, vortices, and swirl.
The control system 90 is operable to control the first plurality of variable-pitch outlet guide vanes 30 and the second plurality of variable-pitch outlet guide vanes 50 in a variety of configurations and arrangements in order to compensate for inlet pressure distortion, vortices and swirl, thus reducing the forcing, stall, flutter, flow separation, and any other undesirable effects in the fan rotor or outlet vanes. For example, in some embodiments, the control system 90 is configured to rotate each vane 32 of the first plurality of guide vanes 30 in unison and is further configured to rotate each second vane 52 of the second plurality of guide vanes 50 in unison. In other words, all of the first plurality of guide vanes 30 move to the same first vane-pitch angle and all of the second plurality of guide vanes 50 move to the same second vane-pitch angle. In such embodiments, the each vane 32 of the first and each vane 52 of the second plurality of guide vanes 30, 50 may be mechanically connected to each other such that not every actuator 74, 84 is required to rotate the vanes, or each vane 32 is rotated individually to the same first vane-pitch angle and each vane 52 is rotated individually to the same second vane-pitch angle, as will be described in detail below. This would require each actuator 74, 84 to actuate the individual vanes 32, 52.
In some embodiments, the control system is further configured to rotate each vane 32 of the first plurality of guide vanes 30 individually relative to each other vane 32, and/or to rotate each vane 52 of the second plurality of guide vanes 50 individually relative to each other vane 52. That is to say, each vane 32, 52 may be rotated without moving any of the other vanes of the first and second plurality of guide vanes 30, 50. This allows for the vanes 32, 52 to be controlled in a variety of configurations. For example, one of the first and second plurality variable-pitch outlet guide vanes 30, 50 may be controlled to be rotated in unison, while the other of the first and second plurality of guide vanes 30, 50 has individually controlled vanes 32, 52. In this scenario, the other of the first and second plurality of guide vanes 30, 50 having individually controlled vanes 32, 52 may account for variations in the fan exit air 15 around the circumference of the area between the first and second plurality of guide vanes 30, 50.
For example, if the rotation of the first plurality of guide vanes 30 causes more undesirable flow effects in certain circumferential sectors, the second plurality of guide vanes 50 may be rotated to different vane-pitch angles to reduce losses from said flow effects. The second plurality of guide vanes 50 may be each rotated individually to different vane-pitch angles to account for this. In other embodiments, the second plurality of guide vanes 50 may be grouped into circumferential sectors, where each vane 52 of each circumferential sector is rotated to a unique vane-pitch angle. In other embodiments, the first plurality of guide vanes 30 may be rotated individually to different vane-pitch angels or by circumferential sectors such that the second plurality of guide vanes 50 may be rotated in unison to most efficiently reduce losses created by the fan exit air 15 flowing over the fan blades 22 and through the first plurality of guide vanes 30.
In some embodiments, the control system 90 is configured to rotate at least two different groups of outlet guide vanes 32, 52. For example, the control system 90 may be configured to selectively rotate each group of outlet guide vanes 32, 52 to create non-uniform backpressure that drives the fan inlet distortion flows within the inlet fan to change or redistribute around the circumference of the inlet fan. This locally reduces loading on fan blades 22 within a lip separated flow with low local pressure to reduce forcing and/or improve the uniformity of flow in general through the fan to reduce forcing. In particular, fully opening (allowing full flow through the guide vanes) at least one group of outlet guide vanes 32, 52 and fully closing at least one further group of outlet guide vanes 32, 52 (allowing no flow through the guide vanes) reduces a tendency for a local stall of the fan blades 22 that could lead to early overall stall in the fan. In some embodiments, the control system 90 is configured to rotate a large group of outlet guide vanes 32, 52 which counters bulk swirling flows or local changes to improve localized intake swirl gradients to improve fan performance and operability.
In some embodiments, the first plurality of variable-pitch outlet guide vanes 30 includes a third variable-pitch outlet guide vane 42 different from the first variable-pitch outlet guide vane 32 and the second plurality of variable-pitch outlet guide vanes 50 includes a fourth variable-pitch outlet guide vane 62 different from the second variable-pitch outlet guide vane 52, as shown in
In some embodiments, the third outlet guide vanes 42 may be mechanically tied together or ganged in a group of vanes different than a group of the first outlet guide vanes 32 which are also mechanically tied together or ganged. In this embodiment, a first connector arm 47 mechanically ties together the third outlet guide vanes 42, and a second connector arm 49 mechanically ties together the first outlet guide vanes 32. Similarly, the fourth outlet guide vanes 62 may be mechanically tied together or ganged in a group of vanes different than a group of the second outlet guide vanes 52 which are also mechanically tied together or ganged. In this embodiment, a first connector arm 67 mechanically ties together the fourth outlet guide vanes 62, and a second connector arm 69 mechanically ties together the second outlet guide vanes 52. In this embodiment, each group of guide vanes 32, 42, 52, 62 includes a single actuator 74, 84 configured to control rotation of that specific group of guide vanes 32, 42, 52, 62. Each guide vane 32, 42, 52, 62 also includes an actuator arm 76, 86 that connects the vane 32, 42, 52, 62 to its respective connector arm 47, 49, 67, 69 so as to mechanically couple each vane group together.
In some embodiments, the outlet guide vane assembly 28 only includes a single row of the first plurality of outlet guide vanes 30, as shown in
In at least one additional embodiment, the outlet guide vane assembly 28 only includes a single row of the first plurality of outlet guide vanes 30 that are broken into unique groups of vanes 32, as shown in
In at least some embodiments, the outlet guide vane assembly 28 only includes a single row of the first plurality of outlet guide vanes 30 that are individually controllable, as shown in
In some embodiments, the first plurality of variable-pitch outlet guide vanes 30 includes a first group of first vanes 32 and a second group of first vanes 32 different from the first group of guide vanes 32. Similarly, the second plurality of variable-pitch outlet guide vanes 50 includes a third group of second vanes 52 and a fourth group of second vanes 52 different from the third group of second vanes 52. The control system 90 is configured to rotate the first group of first vanes 32 to a first vane-pitch angle and the second group of first vanes 32 to a third vane-pitch angle that is different from the first vane-pitch angle. Similarly, the control system 90 to rotate the third group of second vanes 52 to a second vane-pitch angle and the fourth group of second vanes 52 to a fourth vane-pitch angle that is different from the second vane-pitch angle. The groups of vanes 32, 52 may be individually controlled or each group may be ganged together. For example, in some embodiments, one half of the first plurality of outlet guide vanes 30 is the first group and the other half of the first plurality of outlet guide vanes 30 is the second group. Similarly, one half of the second plurality of outlet guide vanes 50 is the third group and the other half of the second plurality of outlet guide vanes 50 is the fourth group.
In some embodiments, the control system 90 utilizes predetermined arrangements of the first and second plurality of variable-pitch outlet guide vanes 30, 50 that are based on predetermined measurements and data taken in predetermined engine operating conditions and predetermined airflow characteristics. As such, the control system 90 is configured to rotate the first and second plurality of guide vanes 30, 50 to specific predetermined arrangements based on the operating condition and/or airflow characteristic(s) of the fan exit air 15 or the inlet air that the engine 10 and fan assembly 12 are operating in.
In other embodiments, the control system 90 includes at least one sensor 92 configured to take real-time measurements of the air flow within the fan duct passage 24 and of forces acting on the fan assembly components, as shown in
In some embodiments, the control system 90 further includes a subsystem control that is integrated with other engine controls to further control reduction of losses created by undesirable variations in the air flow and improve engine performance and efficiency. For example, if rotation of outlet guide vanes 30, 50 resulted in a fan flow drop, the subsystem control is configured to compensate for this by increasing the fan speed in order to maintain thrust, and/or by changing the exhaust area of the engine 10 in order to further reduce the losses and improve engine efficiency.
In some embodiments, the at least one sensor 92 may be located proximate to the fan blades 22, proximate to the first and second plurality of guide vanes 30, 50, or both, as shown in
In the illustrative embodiment, the functionality of the control system 90 described herein may be implemented in various processing and computing devices, and may be located within the engine 10 or outside of the engine 10. Moreover, the functionality may be configured to operate on executable software provided on the processing and computing devices. Furthermore, the functionality disclosed herein may be implemented in various configurations using computer-readable media for carrying or having computer-executable instructions or data structures stored thereon. Such computer-readable media can be any available media that can be accessed by a general purpose or special purpose computer. By way of example, and not limitation, such computer-readable media can comprise physical storage and/or memory media such as RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to carry or store desired program code means in the form of computer-executable instructions or data structures and which can be accessed by a general purpose or special purpose computer. Computer-executable instructions comprise, for example, instructions and data which cause a general purpose computer, special purpose computer, or special purpose processing device to perform a certain function or group of functions.
A second embodiment of an outlet guide vane assembly 128 is shown in
Similar to the outlet guide vane assembly 28, the outlet guide vane assembly 128 is located in the fan duct 20 axially downstream of the inlet fan blades 22 and is configured to adjust a direction of the fan exit air 15 received from the plurality of fan blades 22. In the illustrative embodiment, the outlet guide vane assembly 128 includes a single plurality of variable-pitch outlet guide vanes 130 including a first variable-pitch outlet guide vane 131 that extends radially relative to the central axis 11, as shown in
The first variable-pitch outlet guide vane 131 includes a leading edge portion 132 and a trailing edge portion 152 rotatably coupled to an aft end of the leading edge portion 132, as shown in
In the illustrative embodiment, the leading edge portion includes an airfoil shape having a leading edge 134 located at a forward end of the leading edge portion 132, a trailing edge 135 axially spaced apart from the leading edge 134 and located at an aft end of the leading edge portion 132, a pressure side surface 136 that extends between the leading edge 134 and the trailing edge 135 on one side of the leading edge portion 132, and a suction side surface 137 that extends between the leading edge 134 and the trailing edge 135 on an opposite side of the leading edge portion 132.
The trailing edge portion 152 similarly includes a leading edge 154 located at a forward end of the trailing edge portion 152, a trailing edge 155 axially spaced apart from the leading edge 154 and located at an aft end of the trailing edge portion 152, a pressure side surface 156 that extends between the leading edge 154 and the trailing edge 155 on one side of the trailing edge portion 152, and a suction side surface 157 that extends between the leading edge 154 and the trailing edge 155 on an opposite side of the trailing edge portion 152.
As can be seen in
The first actuation assembly 172 is configured to control rotation of the first variable-pitch outlet guide vane 131, as shown in
Similarly to the outlet guide vane assembly 28, the control system 90 is configured to control the plurality of actuation assemblies 170, in particular the first actuation assembly 172, so as to rotate the leading edge portion 132 and the trailing edge portion 152 of each guide vane 131 of the plurality of guide vanes 130 to a first arrangement in which the leading edge portion 132 and the trailing edge portion 152 are rotated to specific angles. In particular, the first actuation assembly 172 is configured to rotate the leading edge portion 132 to a first leading edge angle in response to the gas turbine engine operating at a given operating condition so as to redirect the fan exit air 15 in a first direction and is further configured to rotate the trailing edge portion 152 to a first trailing edge angle relative to the leading edge portion 132 in order to redirect the fan exit air 15 flowing in the first direction in a second direction to minimize losses created by distortions in fan inlet air and created by the leading edge portion redirecting the fan exit air in the first direction. In the illustrative embodiment, the control system 90 is configured to rotate the trailing edge portion 152 to redirect the fan exit air 15 in a second direction different than the first direction such that the fan exit air 15 returns to an axial flow direction, or as close to axial as possible given the air flow characteristics in the fan duct 20 and the operating conditions of the engine.
In the illustrative embodiment, the first variable-pitch outlet guide vane 131 further includes a vane stem 135 extending between and connected to a radially outer end 139 of the leading edge portion 132 and to the first actuator 174, as shown in
The leading edge portion 132 includes a radially extending leading edge portion trim cavity 145 formed within the leading edge portion 132 and that opens at the radially outer end 139 of the leading edge portion 132, as shown in
The first actuation assembly 172 further includes a cam 186 coupled to a radially inner portion of the control rod 185 and located within the leading edge portion trim cavity 145 of the leading edge portion 132, as shown in
The second actuator 184 is configured to rotate the control rod 185 so as to rotate the cam 186, as suggested by
Similarly to the outlet guide vane assembly 28, the control system 90 is operable to control the leading edge portion 132 and the trailing edge portion 152 of each guide vane 131 of the plurality of guide vanes 130 in a variety of configurations and arrangements in order to compensate for inlet pressure distortion, vortices and swirl, thus reducing the forcing, stall, flutter, flow separation, and any other undesirable effects in the fan rotor or outlet vanes.
In some embodiments, the control system 90 is operably connected to the plurality of actuation assemblies 170 and is configured to rotate the leading edge portion 132 of each guide vane 131 of the plurality of guide vanes 130 in unison via first actuators 174 of each guide vane 131. The control system 90 is further configured to rotate the trailing edge portion 152 of each guide vane 131 in unison via second actuators 184 of each guide vane 131.
The control system 90 is further configured to rotate the leading edge portion 132 of each guide vane 131 of the plurality of guide vanes 130 individually relative to the other leading edge portions 132 of the plurality of guide vanes 131 and/or rotate the trailing edge portion 152 of each guide vane 131 individually relative to the other trailing edge portions 152 of the plurality of guide vanes 131. The control system 90 is also configured to rotate both the leading edge portion 132 and the trailing edge portion 152 of each guide vane 131 individually.
In some embodiments, the plurality of variable-pitch outlet guide vanes 130 includes a second variable-pitch outlet guide vane (not shown) different from the first guide vane 131. The control system 90 is configured to rotate the leading edge portion of the second variable-pitch outlet guide vane to a second leading edge portion angle that is different than the first leading edge portion angle of the leading edge portion 132 of the first guide vane 131. The control system 90 is further configured to rotate the trailing edge portion 152 of the second variable-pitch outlet guide vane to a second trailing edge portion angle that is different than the first trailing edge portion angle of the trailing edge portion 152 of the first guide vane 131.
In some embodiments, the leading edge portions 132 and the trailing edge portions 152 the leading edge portions 132 of each vane 131 may be mechanically connected to each other such that not every actuator 174 is required to rotate the leading edge portions 132. Similarly, the trailing edge portions 152 of each vane 131 may be mechanically connected to each other such that not every actuator 184 is required to rotate the trailing edge portions 152. Alternatively, each leading edge portion 132 is rotated individually to the same first vane-pitch angle and each trailing edge portion 152 is rotated individually to the same second vane-pitch angle. This would require each actuator 174, 184 to actuate the individual edge portions 132, 152.
Similarly to the outlet guide vane assembly 28, the control system 90 being configured to rotate individual edge portions 132, 152 and/or mechanically connected edge portions 132, 152 allows for the edge portions 132, 152 to be controlled in a variety of configurations. For example, if the rotation of the leading edge portions 132 causes more undesirable flow effects in certain circumferential sectors, the trailing edge portions 152 of the vanes 131 may be rotated to different angles to reduce losses from said flow effects. The trailing edge portions 152 may be each rotated individually to different vane-pitch angles to account for this. In other embodiments, the vanes 131 may be grouped into circumferential sectors, where each leading edge portion 132 and each trailing edge portion 152 of the vanes 131 of each circumferential sector are rotated to a unique leading edge portion angle and trailing edge portion angle. The rotation of the trailing edge portion 152 also reduces mechanical loading on the overall vane 130.
A second embodiment of an outlet guide vane assembly 228 is shown in
Similar to the outlet guide vane assembly 28, the outlet guide vane assembly 228 is located in the fan duct 20 axially downstream of the inlet fan blades 22 and is configured to adjust a direction of the fan exit air 15 received from the plurality of fan blades 22. In the illustrative embodiment, the outlet guide vane assembly 228 includes a single plurality of variable-pitch outlet guide vanes 230 including a first variable-pitch outlet guide vane 231 that extends radially relative to the central axis 11, as shown in
The first variable-pitch outlet guide vane 231 includes a leading edge portion 232 and a partial trailing edge portion 252 rotatably coupled to a recessed aft end 235 of the leading edge portion 232, as shown in
In the illustrative embodiment, the leading edge portion includes an airfoil shape having a leading edge 234 located at a forward end of the leading edge portion 232, an aftmost trailing edge 238 axially spaced apart from the leading edge 234 and located at an axially aftmost end of the leading edge portion 232, the recessed aft end 235 located axially forward of the aftmost trailing edge 238. The leading edge portion 232 further includes a pressure side surface 236 that extends between the leading edge 234 and the aftmost trailing edge 238 and the recessed aft end 235 on one side of the leading edge portion 232, and a suction side surface 237 that extends between the leading edge 234 and the aftmost trailing edge 238 and the recessed aft end 235 on an opposite side of the leading edge portion 232.
The trailing edge portion 252 similarly includes a leading edge 254 located at a forward end of the trailing edge portion 252, a trailing edge 255 axially spaced apart from the leading edge 254 and located at an aft end of the trailing edge portion 252, a pressure side surface 256 that extends between the leading edge 254 and the trailing edge 255 on one side of the trailing edge portion 252, and a suction side surface 257 that extends between the leading edge 254 and the trailing edge 255 on an opposite side of the trailing edge portion 252. In the illustrative embodiment, the axial extent of the trailing edge portion 252 from the leading edge 254 to the trailing edge 255 is sized such that the trailing edge 255 is axially aligned with the aftmost trailing edge 238 of the leading edge portion 232.
Moreover, the trailing edge portion 252 is sized radially to be approximately half of the radial extent of the leading edge portion 232, and is arranged such that a radially inner end of the trailing edge portion 252 is co-radial with a radially inner end 238 of the vane 231. In other embodiments, the trailing edge portion 252 is sized radially to be approximately half of the radial extent of the leading edge portion 232, and is arranged such that a radially outer end of the trailing edge portion 252 is co-radial with a radially outer end 239 of the vane 231. In other embodiments, the trailing edge portion 252 is sized radially to be more than half of the radial extent of the leading edge portion 232, and is arranged such that the radially inner end of the trailing edge portion 252 is co-radial with the radially inner end 238 of the vane 231. In other embodiments, the trailing edge portion 252 is sized radially to be more than half of the radial extent of the leading edge portion 232, and is arranged such that the radially outer end of the trailing edge portion 252 is co-radial with the radially outer end 239 of the vane 231.
In other embodiments, the trailing edge portion 252 is sized radially to be less than half of the radial extent of the leading edge portion 232, and is arranged such that the radially inner end of the trailing edge portion 252 is co-radial with the radially inner end 238 of the vane 231. In other embodiments, the trailing edge portion 252 is sized radially to be less than half of the radial extent of the leading edge portion 232, and is arranged such that the radially outer end of the trailing edge portion 252 is co-radial with the radially outer end 239 of the vane 231. In other embodiments, the trailing edge portion 252 is arranged radially between the radially outer end 239 and the radially inner end 238 of the vane 231 such that neither the radially outer end or the radially inner end of the trailing edge portion 252 is co-radial with the radially inner end 238 and the radially outer end 239 of the vane 231.
As can be seen in
The first actuation assembly 272 is configured to control rotation of the first variable-pitch outlet guide vane 231, as shown in
Similarly to the outlet guide vane assemblies 28, 128, the control system 90 is configured to control the plurality of actuation assemblies 270, in particular the first actuation assembly 272, so as to rotate the leading edge portion 232 and the trailing edge portion 252 of each guide vane 231 of the plurality of guide vanes 230 to a first arrangement in which the leading edge portion 232 and the trailing edge portion 252 are rotated to specific angles. In particular, the first actuation assembly 272 is configured to rotate the leading edge portion 232 to a first leading edge angle in response to the gas turbine engine operating at a given operating condition so as to redirect the fan exit air 15 in a first direction and is further configured to rotate the trailing edge portion 252 to a first trailing edge angle relative to the leading edge portion 232 in order to redirect the fan exit air 15 flowing along the portion of the leading edge portion 232 radially aligned with the trailing edge portion 252 in a first direction in a second direction to minimize losses created by distortions in fan inlet air and created by the leading edge portion redirecting the fan exit air in the first direction. In the illustrative embodiment, the control system 90 is configured to rotate the trailing edge portion 252 to redirect the fan exit air 15 in a second direction different than the first direction such that the fan exit air 15 returns to an axial flow direction, or as close to axial as possible given the air flow characteristics in the fan duct 20 and the operating conditions of the engine.
In the illustrative embodiment, the first variable-pitch outlet guide vane 231 further includes a vane stem 235 extending between and connected to a radially outer end 239 of the leading edge portion 232 and to the first actuator 274, as shown in
The leading edge portion 232 includes a radially extending leading edge portion trim cavity 245 formed within the leading edge portion 232 and that opens at the radially outer end 239 of the leading edge portion 232, as shown in
The first actuation assembly 272 further includes a cam 286 coupled to a radially inner portion of the control rod 285 and located within the leading edge portion trim cavity 245 of the leading edge portion 232, as shown in
The second actuator 284 is configured to rotate the control rod 285 so as to rotate the cam 286, as suggested by
Similarly to the outlet guide vane assemblies 28, 128, the control system 90 is operable to control the leading edge portion 232 and the trailing edge portion 252 of each guide vane 231 of the plurality of guide vanes 230 in a variety of configurations and arrangements in order to compensate for inlet pressure distortion, vortices and swirl, thus reducing the forcing, stall, flutter, flow separation, and any other undesirable effects in the fan rotor or outlet vanes. In some embodiments, the control system 90 is operably connected to the plurality of actuation assemblies 270 and is configured to rotate the leading edge portion 232 of each guide vane 231 of the plurality of guide vanes 230 in unison via first actuators 274 of each guide vane 231. The control system 90 is further configured to rotate the trailing edge portion 252 of each guide vane 231 in unison via second actuators 284 of each guide vane 231.
The control system 90 is further configured to rotate the leading edge portion 232 of each guide vane 231 of the plurality of guide vanes 230 individually relative to the other leading edge portions 232 of the plurality of guide vanes 231 and/or rotate the trailing edge portion 252 of each guide vane 231 individually relative to the other trailing edge portions 252 of the plurality of guide vanes 231. The control system 90 is also configured to rotate both the leading edge portion 232 and the trailing edge portion 252 of each guide vane 231 individually.
In some embodiments, the plurality of variable-pitch outlet guide vanes 230 includes a second variable-pitch outlet guide vane (not shown) different from the first guide vane 231. The control system 90 is configured to rotate the leading edge portion of the second variable-pitch outlet guide vane to a second leading edge portion angle that is different than the first leading edge portion angle of the leading edge portion 232 of the first guide vane 231. The control system 90 is further configured to rotate the trailing edge portion 252 of the second variable-pitch outlet guide vane to a second trailing edge portion angle that is different than the first trailing edge portion angle of the trailing edge portion 252 of the first guide vane 231.
In some embodiments, the leading edge portions 232 and the trailing edge portions 252 the leading edge portions 232 of each vane 231 may be mechanically connected to each other such that not every actuator 274 is required to rotate the leading edge portions 232. Similarly, the trailing edge portions 252 of each vane 231 may be mechanically connected to each other such that not every actuator 284 is required to rotate the trailing edge portions 252. Alternatively, each leading edge portion 232 is rotated individually to the same first vane-pitch angle and each trailing edge portion 252 is rotated individually to the same second vane-pitch angle. This would require each actuator 274, 284 to actuate the individual edge portions 232, 252.
Similarly to the outlet guide vane assemblies 28, 128, the control system 90 being configured to rotate individual edge portions 232, 252 and/or mechanically connected edge portions 232, 252 allows for the edge portions 232, 252 to be controlled in a variety of configurations. For example, if the rotation of the leading edge portions 232 causes more undesirable flow effects in certain circumferential sectors, the trailing edge portions 252 of the vanes 231 may be rotated to different angles to reduce losses from said flow effects. The trailing edge portions 252 may be each rotated individually to different vane-pitch angles to account for this. In other embodiments, the vanes 231 may be grouped into circumferential sectors, where each leading edge portion 232 and each trailing edge portion 252 of the vanes 231 of each circumferential sector are rotated to a unique leading edge portion angle and trailing edge portion angle.
In some embodiments of the present disclosure, an outlet guide vane assembly includes a plurality of variable-pitch outlet guide vanes may include a combination of variable-pitch outlet guide vanes 30, 50, variable-pitch outlet guide vanes 130, and variable-pitch outlet guide vanes 230. For example, in some embodiments, the outlet guide vane assembly includes a first row of variable-pitch outlet guide vanes 30 and a second row located axially aft of the first row of variable-pitch outlet guide vanes 130 or variable-pitch outlet guide vanes 230. In other embodiments, the first row of variable-pitch outlet guide vanes includes at least one first circumferential sector that includes the variable-pitch outlet guide vanes 30 and at least one second circumferential sector that includes the variable-pitch outlet guide vanes 130 or the variable-pitch outlet guide vanes 230. This embodiment may also include a similar second row of variable-pitch outlet guide vanes that include a similar combination of vanes.
In some embodiments, the leading edge portions 132, 232 of each variable-pitch outlet guide vane 130, 230 is ganged together, and the trailing edge portions 152, 252 of each variable-pitch outlet guide vane 130, 230 is ganged together. In some embodiments, unique groups of the leading edge portions 132, 232 of some variable-pitch outlet guide vanes 130, 230 are ganged together, and unique groups of the trailing edge portions 152, 252 of some variable-pitch outlet guide vanes 130, 230 are ganged together. In some embodiments, each leading edge portions 132, 232 is mechanically tied to its respective trailing edge portion 152, 252 such that rotation of the leading edge portion 132, 232 causes rotation of the trailing edge portion 152, 252.
In some embodiments, all of the leading edge portions 132, 232 of each variable-pitch outlet guide vane 130, 230 are ganged together, while only unique groups of the trailing edge portions 152, 252 of some variable-pitch outlet guide vanes 130, 230 are ganged together. In some embodiments, all of the trailing edge portions 152, 252 of each variable-pitch outlet guide vane 130, 230 are ganged together, while only unique groups of the leading edge portions 132, 232 of some variable-pitch outlet guide vanes 130, 230 are ganged together. The ganging and mechanical tying of the leading and trailing edge portions 132, 232, 152, 252 of the vanes 130, 230 may be applicable to multiple rows of vanes as well.
While the disclosure has been illustrated and described in detail in the foregoing drawings and description, the same is to be considered as exemplary and not restrictive in character, it being understood that only illustrative embodiments thereof have been shown and described and that all changes and modifications that come within the spirit of the disclosure are desired to be protected.
Embodiments of the present disclosure were made with government support under Contract No. FA8650-19-F-2078 awarded by the U.S. Air Force. The government may have certain rights.
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| 20230061349 A1 | Mar 2023 | US |
