Patent Application
20240309775
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, a fan comprising 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, and an outlet guide vane assembly located in the fan duct axially downstream of the fan and configured to adjust a direction of incoming fan exit air received from the plurality of fan blades and reduce incidence between the outlet guide vane assembly and the fan exit air.
The outlet guide vane assembly includes a first variable leading edge outlet guide vane that extends radially relative to the central axis and includes a leading edge portion and a fixed aft portion, the leading edge portion including a first tip segment configured to rotate about a leading edge pitch axis and a first hub segment located radially inward of and separate from the first tip segment, the first hub segment configured to independently rotate about the leading edge pitch axis relative to the first tip segment, a first air manipulating member arranged radially between the first tip segment and the first hub segment and configured to manipulate at least a portion of the incoming fan exit air flowing over the leading edge portion, and at least one actuation assembly configured to selectively rotate the first tip segment about the leading edge pitch axis to a first pitch angle relative to the incoming fan exit air and configured to selectively rotate the first hub segment independent of the first tip segment about the leading edge pitch axis to a second pitch angle relative to the incoming fan exit air.
In some embodiments, the at least one actuation assembly is configured to rotate the first tip segment and the first hub segment to the first pitch angle and the second pitch angle which is different than the first pitch angle.
In some embodiments, the at least one actuation assembly includes a first actuation assembly arranged radially outward of the leading edge portion and configured to rotate the first tip segment to the first pitch angle.
In some embodiments, the first air manipulating member is arranged proximate to a radially inner side of the first tip segment and proximate to a radially outer side of the first hub segment.
In some embodiments, a radial gap is formed between the radially inner side of the first tip segment and the radially outer side of the first hub segment, and wherein the first air manipulating member has a radial extent that is sized so as to seal off the incoming fan exit air from flowing through the radial gap.
In some embodiments, the first air manipulating member is a winglet defining a radially outer surface that is generally planar and faces radially outwardly and a radially inner surface that is generally planar and faces radially inwardly, and wherein the winglet includes an axially aft end and an axially forward edge.
In some embodiments, a width of the winglet is equal to or greater than a width of the first tip segment and the first hub segment along an entire axial extent of the first tip segment and the first hub segment.
In some embodiments, a width of the winglet at the axially aft end is less than a length of the forward edge, the forward edge is curved so as to match a path of movement of a leading edge of at least one of the first tip segment and the first hub segment, the path of movement has a maximum first end point and a maximum second end point, and the length of the forward edge is equal to or extends beyond the maximum first end point and the maximum second end point of the path of movement of the at least one of the first tip segment and the first hub segment.
In some embodiments, the axially aft end of the winglet is coupled to an axially forward end of the fixed aft portion.
In some embodiments, the first air manipulating member is a seal, and wherein an outer perimeter of the seal generally corresponds to an outer perimeter of each of the first tip segment and the first hub segment.
In some embodiments, the seal includes an axially aft end that is coupled to an axially forward end of the fixed aft portion.
In some embodiments, the seal is attached to one of the radially inner side of the first tip segment and the radially outer side of the first hub segment.
In some embodiments, the at least one actuation assembly further includes a second actuation assembly arranged radially inward of the leading edge portion and configured to rotate the first hub segment to the second pitch angle.
In some embodiments, the first actuation assembly includes a first actuation head coupled to the first tip segment and a first actuation arm coupled to the first actuation head, rotation of the first actuation arm causes rotation of the first actuation head which causes rotation of first tip segment so as to rotate the first tip segment to the first pitch angle, the second actuation assembly includes a second actuation head coupled to the first hub segment and a second actuation arm coupled to the second actuation head, and rotation of the second actuation arm causes rotation of the second actuation head which causes rotation of first hub segment so as to rotate the first hub segment independent of the first tip segment to the second pitch angle.
According to a further aspect of the present disclosure, a fan assembly for a gas turbine engine includes a fan duct arranged circumferentially around a central axis, a fan adapted to rotate about the central axis to force fan exit air toward an aft end of the fan duct, and an outlet guide vane assembly located in the fan duct axially downstream of the fan and configured to adjust a direction of incoming fan exit air received from the plurality of fan blades and reduce incidence between the outlet guide vane assembly and the fan exit air.
The outlet guide vane assembly includes a first variable leading edge outlet guide vane including a leading edge portion and a fixed aft portion, the leading edge portion including a first tip segment configured to rotate about a leading edge pitch axis and a first hub segment located radially inward of and separate from the first tip segment, a first air manipulating member arranged radially between the first tip segment and the first hub segment, and at least one actuation assembly configured to selectively rotate the first tip segment about the leading edge pitch axis to a first pitch angle relative to the incoming fan exit air and configured to selectively rotate the first hub segment independent of the first tip segment about the leading edge pitch axis to a second pitch angle relative to the incoming fan exit air.
In some embodiments, the at least one actuation assembly includes a first actuation assembly arranged radially outward of the leading edge portion and configured to rotate the first tip segment to the first pitch angle.
In some embodiments, the first air manipulating member is arranged proximate to a radially inner side of the first tip segment and proximate to a radially outer side of the first hub segment, a radial gap is formed between the radially inner side of the first tip segment and the radially outer side of the first hub segment, and the first air manipulating member has a radial extent that is sized so as to seal off the incoming fan exit air from flowing through the radial gap.
In some embodiments, the first air manipulating member is a winglet defining a radially outer surface that is generally planar and faces radially outwardly and a radially inner surface that is generally planar and faces radially inwardly, the winglet includes an axially aft end and an axially forward edge, a width of the winglet is equal to or greater than a width of the first tip segment and the first hub segment along an entire axial extent of the first tip segment and the first hub segment, and a width of the winglet at the axially aft end is less than a length of the forward edge.
In some embodiments, the first air manipulating member is a seal, and wherein an outer perimeter of the seal generally corresponds to an outer perimeter of each of the first tip segment and the first hub segment.
According to a further aspect of the present disclosure, a method comprises arranging a fan duct circumferentially around a central axis, providing a fan comprising 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, arranging an outlet guide vane assembly in the fan duct axially downstream of the fan and configured to adjust a direction of incoming fan exit air received from the plurality of fan blades and reduce incidence between the outlet guide vane assembly and the fan exit air, the outlet guide vane assembly including a first variable leading edge outlet guide vane extending radially relative to the central axis and including the leading edge portion and a fixed aft portion, the leading edge portion including a first tip segment configured to rotate about a leading edge pitch axis and a first hub segment located radially inward of and separate from the first tip segment, the first hub segment configured to independently rotate about the leading edge pitch axis relative to the first tip segment, arranging a first air manipulating member radially between the first tip segment and the first hub segment and configured to manipulate at least a portion of the incoming fan exit air flowing over the leading edge portion, and arranging at least one actuation assembly relative to the first tip segment configured to selectively rotate the first tip segment about the leading edge pitch axis to a first pitch angle relative to the incoming fan exit air and configured to selectively rotate the first hub segment independent of the first tip segment about the leading edge pitch axis to a second pitch angle relative to the incoming fan exit air.
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 a fan 21 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 reduce the incidence between the outlet guide vane assembly 28 and the fan exit air 15 received from the plurality of fan blades 22 and return the flow to generally axial flow, as shown in
The first variable leading edge outlet guide vane 30 extends radially outward relative to the central axis 11, as shown in
As shown in
Together, the first tip and hub segments 32, 42 form the leading edge portion 31. As shown in
The first tip and hub segments 32, 42 are configured to rotate about the leading edge pitch axis 39, as shown in
The first hub segment 42 is configured to independently rotate about the leading edge pitch axis 39 relative to the first tip segment 32, and may include a small radial gap therebetween. In some embodiments, the first hub segment 42 can include a hinge rod 47 extending radially outwardly from the radially outer side 45 of the first hub segment 42. The first tip segment 32 can include a hinge rod receiving cavity 37 configured to securely receive the hinge rod 42 so as to add stability to the rotation of the two segments 32, 42 relative to each other while allowing for independent rotation. The hinge rod 47 of the first hub segment 42 and the hinge rod receiving cavity 37 of the first tip segment 32 can each be cylindrical and aligned with the leading edge pitch axis 39. In some embodiments in which the first tip and hub segments 32, 42 are formed of a sufficiently stiff material, a hinge rod may be omitted, as shown in
To rotate independently, the illustrative embodiment of the outlet guide vane assembly 28 includes a first actuation assembly 70 associated with the first tip segment 32 and a second actuation assembly 80 associated with the first hub segment 42. The first actuation assembly 70 is arranged radially outward of the leading edge portion 31 and includes a first actuation arm 74 and a first actuation head 76, the first actuation arm 74 extending axially away from the first actuation head 76. The second actuation assembly 80 is arranged radially inward of the leading edge portion 31 and includes a second actuation arm 84 and a second actuation head 86, the second actuation arm 84 extending axially away from the second actuation head 86.
The first actuation head 76 extends through the outer fan duct casing 19 and is fixedly coupled to the radially outer side 35 of the first tip segment 32, as shown in
The second actuation head 86 extends through the inner wall 23 and is fixedly coupled to the radially inner side 46 of the first hub segment 42, as shown in
As will be described in greater detail below, the first and second actuation arms 74, 84 are configured to be moved generally circumferentially relative to the first and second actuation heads 76, 86, respectively, by annular rings, segmented annular rings, or individual actuators so as to pivot the actuation arms 74, 84 about the leading edge pitch axis 39. In particular, the actuation arms 74, 84 may be selectively pivoted about the leading edge pitch axis 39 so as to rotate the respective actuation head 76, 86 so as to selectively rotate the first tip and hub segments 32, 42 about the leading edge pitch axis 39. As a result, the first tip segment 32 can be selectively rotated about the leading edge pitch axis 39 to a first pitch angle relative to the incoming fan exit air 15. Similarly, the first hub segment 42 can be selectively rotated about the leading edge pitch axis 39 to a second pitch angle relative to the incoming fan exit air 15. The fixed trailing edge 50 rotates any flow back to near axial to minimize loss from swirl.
In this way, the first tip and hub segments 32, 42 can be individually controlled with respect to each other to the same or differing angles, thus allowing for a multitude of segment positions and arrangements to be achieved. This provides for great flexibility in managing incoming airflows which may include distortions and disturbances. This can be particularly useful in embedded engine applications with complex intake and inlet duct geometries. In such scenarios, the distortion flows have more significant gradients and vortices, even in flight, so accommodation is necessary to maintain fan operability and performance.
In one exemplary arrangement, as shown in
As shown in
As can be seen in
In some scenarios, it may be beneficial to have more control over individual sections of the plurality of variable leading edge outlet guide vanes 30 or individual vanes 30. This may be particular useful when the engine experiences more significantly distorted flows, such as in embedded engine applications. Sectional control or individual control would provide additional flexibility to accommodate as much flow variation as possible to recover operability and performance margins. For example, as an aircraft maneuvers through ground crosswind or variations of flight orientations such as sideslip and pitch variations, the plurality of variable leading edge outlet guide vanes 30 can be rotationally moved in sections or independently to best reset the inlet angles and maximize the fan operability envelope. The optimized rest of the inlet angles improves stall margin, improves efficiency and performance, and reduces fan forcing debits.
As can be seen in
In this configuration, the first and second annular ring segments 62S1, 62S2 can be configured to independently rotate about the central axis 11 so as to move each actuation arm 74, 84 coupled thereto generally circumferentially relative to the first and second actuation heads 76, 86, or in other words, to pivot each actuation arm 74, 84 coupled thereto about the leading edge pitch axis 39. The first and second annular ring segments 62S1, 62S2 are circumferentially spaced apart a great enough distance to allow maximum movement relative to each other. For example, in some scenarios, the first annular ring segment 62S1 may be moved in an opposing circumferential direction to the second annular ring segment 62S2 such that the respective tip segments 32 of their associated vanes 30 are rotated in opposing rotational directions. The third and fourth annular ring segments 64S1, 64S2 can be similarly configured.
The outlet guide vane assembly 28 can include multiple annular ring segments similar to the segments 62S1, 62S2, 64S1, 64S2 disposed around the entire circumferential extent of the assembly 28. As such, the multiple annular ring segments can define groups of vanes 30, the tip and hub segments 32, 42 of each being able to be rotated to unique pitch angles based on the circumferential movement and position of their respective annular ring segment. As will be described in detail below, the annular rings 62, 64 may be controlled by a control system 90.
In some embodiments, the control system 90 is configured to rotate each segment 32, 42 of each vane 30 of the first plurality of variable leading edge outlet guide vanes 30 individually relative to each other vane's 30 segments 32, 42, as shown in
In another example, if the rotation of the first plurality of guide vanes 30 causes more undesirable flow effects in certain circumferential sectors, only vanes 30 located in those certain circumferential sectors may be rotated to specific pitch angles to reduce losses from said flow effects, while other vanes 30 may be rotated to different pitch angles. Then, if the flow dynamically encounters different distortions during operation, different circumferential sectors may require vane 30 adjustment. The individual controllability allows for the option to adjust these different circumferential sectors dynamically.
In order to carry out the individual control, the second ends 74B, 84B of the actuation arms 74, 84 may include a control member 75 coupled to an external actuator (not shown) that moves the actuation arms 74, 84 generally circumferentially relative to the first and second actuation heads 76, 86. In other embodiments, the first and second actuation heads 76, 86 may be individually actuated via an actuator coupled directly to the actuation head 76, 86, for example an actuator coupled to a radially outer side of the first actuation head 76 and an actuator coupled to a radially inner side of the second actuation head 86.
As touched on above, by controlling the segments 32, 42 of at least one vane 30 of the plurality of variable leading edge outlet guide vanes 30, the control system 90 is configured to control at least some of the flow of the fan exit air 15 after it passes over and exits the fan blades 22. By controlling the entirety of the plurality of variable leading edge outlet guide vanes 30, the control system 90 can accommodate the overall flow of the fan exit air 15, in particular distorted flow, after it passes over and exits the fan blades 22 in order to control fan blade 22 response to forces acting on the fan blades 22, as well as to reduce losses created by undesirable variations in the air flow. Moreover, because the fan exit air 15 may not be uniform as it exits the fan blades 22, the plurality of variable leading edge outlet guide vanes 30 or the axial passage between the vanes 30 and the fan blades 22 operate further from their ideal design conditions. By adjusting the plurality of variable leading edge outlet guide vanes 30, parameters such as incidence are improved, and detrimental flow conditions and losses in the vanes 30 or the axial passage between the vanes 30 and the fan blades 22 such as fan forcing and stall margin losses are reduced.
In some embodiments, the control system 90 is configured to rotate the segments 32, 42 of each vane 30 of the first plurality of variable leading edge 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 reduce the incidence between the outlet guide vane assembly 28 and the fan exit air 15 received from the plurality of fan blades 22 and redirect the fan exit air 15 in a first direction, in particular a generally axial 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, landing, and aircraft maneuvers of an aircraft having the engine 10 equipped. In each of these operating conditions, the plurality of fan blades 22 and/or the 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 segments 32, 42 of the first plurality of variable leading edge 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 leading edge 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 leading edge outlet guide vanes 30 in response to swirl in the inlet flow. This produces an averaging effect that improves engine performance and efficiency. These arrangements of the vanes 30 can also recover the losses created by flow separation, flow distortions, vortices, and/or swirl.
The control system 90 is operable to control the segments 32, 42 of the first plurality of variable leading edge outlet guide vanes 30 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 30 of the first plurality of guide vanes 30 in unison. In other words, all of the first plurality of guide vanes 30 move to the same first vane-pitch angle. In such embodiments, the each vane 30 may be mechanically connected to each other via the first and second annular rings 62, 64.
In some embodiments, the control system 90 is configured to rotate at least two different groups of the segments 32, 42 of variable leading edge outlet guide vanes 30. For example, the control system 90 may be configured to selectively rotate each group of vanes 30 to create non-uniform backpressure that drives the fan inlet distortion flows within the fan to change or redistribute around the circumference of the 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 vanes 30 and fully closing at least one further group of vanes 30 (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 vanes 30 which counters bulk swirling flows or local changes to improve localized intake swirl gradients to improve fan performance and operability.
In at least one additional embodiment, the plurality of variable leading edge outlet guide vane 30 are broken into unique groups of vanes 30, as shown in
In some embodiments, the first plurality of variable leading edge outlet guide vanes 30 includes a first group of first vanes 30 and a second group of first vanes 30 different from the first group of guide vanes 30. The control system 90 is configured to rotate the first group of first vanes 30 to a first vane-pitch angle and the second group of first vanes 30 to a second vane-pitch angle that is different from the first vane-pitch angle. The groups of vanes 30 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.
In some embodiments, the control system 90 utilizes predetermined arrangements of the plurality of variable leading edge outlet guide vanes 30 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 vanes 30 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, or based on projected operating conditions and/or airflow characteristic(s) that will be encountered by the engine 10 during a mission.
In some embodiments, the predetermined arrangements of the segments 32, 42 of the plurality of variable leading edge outlet guide vanes 30 can be based on previously acquired test data corresponding to specific flight conditions. In a more complex arrangement, the control system 90 could be coupled to measurement systems, such as the at least one sensor 92 described below, that detect flow instabilities associated with impending fan stall to direct vane geometry changes to extend margins. The control system 90 may be more effective near stall as the vanes 30 can redistribute flow conditions to minimize local stall cells. Having smaller ganged vane 30 groups are efficient as well in that such groups only reduce losses locally to extend operability and performance.
In some 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 includes a neural network configured to perform machine learning such that the control system 90 can iterate over the predetermined arrangements in order to calculate new arrangements that are applicable to new variations in the operating condition and/or airflow characteristics that are unaccounted for by the predetermined settings and arrangements.
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 vanes 30 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 plurality of variable leading edge outlet guide vanes 30, 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 person skilled in the art will understand that all features and components of all embodiments described herein, including the guide vane assembly 28 described above and the outlet guide vane assemblies described below can be interchanged and modified to include some elements of some embodiments and other elements of other embodiments. For example, even though some embodiments are shown without a static central portion, these embodiments may include such a central portion, as described herein. Similarly, although some embodiments described two tip segments and two hub segments, some embodiments can include one tip and two hub segments, two tip and one hub segments, each with or without a static central hub section, or other combinations thereof. Similarly, the actuation assemblies can be interchanged, with some embodiments and configurations including pass-through actuation assemblies, two assemblies arranged at the tip and hub, different configurations of segmented and full annular rings, and the like.
Another embodiment of an outlet guide vane assembly 128 is shown in
Similar to the outlet guide vane assembly 28 described above, the outlet guide vane assembly 128 includes first tip and hub segments 132, 142. In this embodiment, an air manipulating member 190 may be arranged in the small radial gap between the first tip and hub segments 132, 142. In particular, in some embodiments, the air manipulating member 190 may be configured as a winglet 190 or platform coupled to an axially forward side 153 of the fixed aft portion 150, as shown in
As shown in
The winglet 190 further includes a forward edge 196 that is curved. In some embodiments, the forward edge 196 is curved to match the rotational path, or path of movement, of the leading edge 133, 143 of the tip and hub segments 132, 142. In particular, the forward edge 196 may include a radius of curvature 197 that matches the rotational path of the tip and hub segments 132, 142, as shown in
As can be seen in
Another embodiment of an outlet guide vane assembly 228 is shown in
Similar to the outlet guide vane assembly 228 described above, the outlet guide vane assembly 228 includes first tip and hub segments 232, 242. In this embodiment, the first variable leading edge outlet guide vane 230 further includes a central portion 248 arranged between the first tip segment 232 and the first hub segment 242 such that the first tip segment 232 and the first hub segment 242 are radially spaced apart. In some embodiments, the central portion may be coupled to and extend axially away from the axially forward side 253 of the fixed aft portion 250. The central portion 248 is configured to be static and not rotate.
As can be seen in
Another embodiment of an outlet guide vane assembly 328 is shown in
Similar to the outlet guide vane assembly 228 described above, the outlet guide vane assembly 328 includes first tip and hub segments 332, 342 and a central portion 348. Unlike the outlet guide vane assembly 228, the outlet guide vane assembly 328 may include a single or multiple air manipulating members 390A, 390B arranged in the small radial gaps between the tip segment 332 and central portion 348 and between the hub segment 342 and central portion 348. The air manipulating members 390A, 390B may be formed similarly to the air manipulating member 190 described above, in particular formed as a seal or winglet.
In some embodiments, one of the air manipulating members 390A, 390B may be formed as a winglet while the other is formed as a seal. In some embodiments, both of the air manipulating members 390A, 390B are formed as a seal. In some embodiments, both of the air manipulating members 390A, 390B are formed as a winglet. In embodiments in which the tip and hub segments 332, 342 are rotationally attached to the central portion 348 via hinge rods similar to those described above, the air manipulating members 390A, 390B can include a cutout (not shown but similar to the cutout 198 shown in
As can be seen in
Another embodiment of an outlet guide vane assembly 428 is shown in
Similar to the outlet guide vane assembly 28 described above, the outlet guide vane assembly 428 includes first tip and hub segments 432, 442. Unlike the vane assemblies 28, 128, 228, 328 described above, the vane assembly 428 only includes a single actuation assembly 470, in particular a first actuation assembly 470 as shown in
As can be seen in
Specifically, the first actuation head 476 has a first cavity 479 formed therethrough that is substantially similarly shaped to the outer surface of the first actuation rod 478. Similarly, the first tip segment 432 includes a second cavity 437 extending therethrough. The second cavity 437 is axially aligned with the first cavity 479, and in particular, both cavities 437, 479 are axially aligned with the leading edge pitch axis 439. As a result, as shown in
In this configuration, the first actuation head 476 is configured to selectively rotate the first tip segment 432 about the leading edge pitch axis 439 to a first pitch angle relative to the incoming fan exit air 15 utilizing similar actuation methodologies as described above, such as via the actuation arm 474 in conjunction with the annular ring 462, ring segments, or individual actuators. The second actuation head 484 is configured to selectively rotate the first hub segment 442 via rotation thereof, which rotates the first actuation rod 478 and thus the first hub segment 442. The first hub segment 442 is rotated independent of the first tip segment 432 about the leading edge pitch axis 439 to a second pitch angle relative to the incoming fan exit air 15. As such, the tip and hub segments 432, 442 can be rotated to the same or different pitch angles based on the design and operation requirements, such as the operating conditions, predetermined angles, and the like described above.
In some embodiments, the first actuation assembly 470 can further include an actuator coupled to the second actuation head 484 that is configured to rotate the second actuation head 484. In some embodiments, the actuator may be a relatively small hydraulic actuator or an electric motor actuator such as a stepper motor directly coupled to the second actuation head 484. In other embodiments, the second action head 484 may be actuated via similar means as to the first actuation head 476, such as via a further actuation arm coupled to an annular ring, ring segments, or individual actuators.
For example, as shown in the alternative actuation arrangement of the vane assembly 428′ of
Similarly, as shown in the alternative actuation arrangement of the vane assembly 428″ of
As shown in
Another embodiment of an outlet guide vane assembly 528 is shown in
Similar to the outlet guide vane assembly 428 described above, the outlet guide vane assembly 528 includes first tip and hub segments 532, 542 and a single actuation assembly 570 configured to move both tip and hub segments 532, 542. In some embodiments, the first actuation assembly 570 can include the first actuation arm 574, as well as an actuator coupled to the second actuation head 584 that is configured to rotate the second actuation head 584. In some embodiments, the actuator may be a relatively small hydraulic actuator or an electric motor actuator such as a stepper motor directly coupled to the second actuation head 584. In other embodiments, the second actuation head 584 may be actuated via similar means as to the first actuation head 576, and similar means as the section actuation head 484, such as via a further actuation arm coupled to an annular ring, ring segments, or individual actuators, such as those shown in
In this embodiment, an air manipulating member 590 similar to the air manipulating members 190, 390A, 390B described above may be arranged in the small radial gap between the first tip and hub segments 532, 542. In particular, in some embodiments, the air manipulating member 590 may be configured as a winglet 590 or platform coupled to an axially forward side 553 of the fixed aft portion 550. In other embodiments, the air manipulating member 590 may be configured as a seal 590S.
Similar to the air manipulating member 190, the air manipulating member 590 may be configured as a winglet 590 that reduce radial flows across the tip and hub segments 532, 542. Also similar to the air manipulating member 190, the air manipulating member 590 may be configured as a seal 590S which is coupled to the axially forward side 553 of the fixed aft portion 550 or directly coupled to one of the radially inner side 536 of the tip segment 532 or the radially outer side 545 of the hub segment 542.
Another embodiment of an outlet guide vane assembly 628 is shown in
Similar to the outlet guide vane assembly 428 described above, the outlet guide vane assembly 628 includes first tip and hub segments 632, 642 and a single actuation assembly 670 configured to move both tip and hub segments 632, 642. In some embodiments, the first actuation assembly 670 can include the first actuation arm 674, as well as an actuator coupled to the second actuation head 684 that is configured to rotate the second actuation head 684. In some embodiments, the actuator may be a relatively small hydraulic actuator or an electric motor actuator such as a stepper motor directly coupled to the second actuation head 684. In other embodiments, the second actuation head 684 may be actuated via similar means as to the first actuation head 676, and similar means as the section actuation head 484, such as via a further actuation arm coupled to an annular ring, ring segments, or individual actuators, such as those shown in
In this embodiment, the first variable leading edge outlet guide vane 630 further includes a central portion 648 arranged between the first tip segment 632 and the first hub segment 642 such that the first tip segment 632 and the first hub segment 642 are radially spaced apart. In some embodiments, the central portion 648 may be coupled to and extend axially away from the axially forward side 653 of the fixed aft portion 650.
As can be seen in
Another embodiment of an outlet guide vane assembly 728 is shown in
Similar to the outlet guide vane assemblies 528, 628 described above, the outlet guide vane assembly 728 includes first tip and hub segments 732A, 742A and a central portion 748. Unlike the assemblies described above, the outlet guide vane assembly 728 further includes a second tip segment 732B and a second hub segment 742B arranged radially between the first tip segment 732A and the central portion 748 and between the first hub segment 742A and the central portion 748, respectively. The additional second tip segment 732B and second hub segment 742B allow for additional variations of the fan exit air 15 flowing over the vane 730.
In order to move all four segments 732A, 732B, 742A, 742B, the assembly 728 includes a first actuation assembly 770A and a second actuation assembly 770B that may be configured substantially similarly to each other. For example, the first actuation head 776A of the first actuation assembly 770A has a first cavity 779A formed therethrough. Similarly, the first tip segment 732A includes a second cavity 737A extending therethrough. The second cavity 737A is axially aligned with the first cavity 779A. As a result, as shown in
Similarly, the first actuation head 776B of the second actuation assembly 770B has a first cavity 779B formed therethrough. Similarly, the first hub segment 742A includes a second cavity 747A extending therethrough. The second cavity 747A is axially aligned with the first cavity 779B. As a result, as shown in
Each actuation rod 778A, 778B has a central axis. In some embodiments, due to the curvature of the leading edge of the leading edge portion 31, the central axes of the actuation rods 778A, 778B may need to be offset to accommodate the curvature and the offset leading edge pitch axes 739A, 739B of the various segments. For example, as shown in
Another embodiment of an outlet guide vane assembly 828 is shown in
Similar to the outlet guide vane assembly 728 described above, the outlet guide vane assembly 828 includes first and second tip and hub segments 832A, 832B, 842A, 842B, a central portion 848, and two actuation assemblies 870A, 870B configured to move the first and second tip and hub segments 832A, 832B, 842A, 842B independently of each other. In this embodiment, an air manipulating member 890 similar to the air manipulating members 190, 390A, 390B, 590 described above may be arranged in the small radial gaps between the first and second tip and hub segments 832A, 832B, 842A, 842B and between the second tip and hub segments 832B, 842B and the central portion 848. In particular, in some embodiments, the air manipulating members 890 may be configured as a winglets 890 or platforms coupled to an axially forward side 853 of the fixed aft portion 850. In other embodiments, the air manipulating members 890 may be configured as seals 890S.
Similar to the air manipulating members 190, 390A, 390B, 590, the air manipulating members 890 may be configured as winglet 890 that reduce radial flows across the first and second tip and hub segments 832A, 832B, 842A, 842B, as shown in
Another embodiment of an outlet guide vane assembly 928 is shown in
Similar to the outlet guide vane assembly 728 described above, the outlet guide vane assembly 928 includes first and second tip and hub segments 932A, 932B, 942A, 942B and two actuation assemblies 970A, 970B configured to move the first and second tip and hub segments 932A, 932B, 942A, 942B independently of each other. Unlike the outlet guide vane assembly 728, the vane assembly 928 does not include a central portion 948. As such, the second hub segment 942B can include a hinge rod 947 extending radially away from the segment 942B and received in a hinge rod receiving cavity 937B of the second tip segment 932B.
It should be appreciated that features and elements of all of the embodiments described above can be used in conjunction with alternative embodiments that would be understood by one of ordinary skill in the art. For example, a vane having three rotatable segments could be configured that includes two radially outer segments that are movable via an actuation assembly similar to the single actuation assembly 470 described above and a single radially inner segment movable via a second actuation assembly. Or, more than four segments may be utilized in a vane arrangement. Such similar alternative embodiments are contemplated by the present disclosure.
The nominal vane cannot be varied, but each of the segmented vane's segments may be rotated so that the distribution of the segmented vane resembles the variation profile.
Moreover, as can be seen in
A method can include arranging a fan duct 20 circumferentially around a central axis 11, providing a fan 21 comprising a plurality of fan blades 22 that extend radially outward relative to the central axis 11 and that are adapted to rotate about the central axis 11 to force fan exit air 15 toward an aft end of the fan duct 20, and arranging an outlet guide vane assembly 128 in the fan duct 20 axially downstream of the fan 21 and configured to adjust a direction of incoming fan exit air 15 received from the plurality of fan blades 22 and reduce incidence between the outlet guide vane assembly 128 and the fan exit air 15, the outlet guide vane assembly 128 including a first variable leading edge outlet guide vane 130 extending radially relative to the central axis 11 and including the leading edge portion 131 and a fixed aft portion 150, the leading edge portion 131 including a first tip segment 132 configured to rotate about a leading edge pitch axis 139 and a first hub segment 142 located radially inward of and separate from the first tip segment 132, the first hub segment 142 configured to independently rotate about the leading edge pitch axis 139 relative to the first tip segment 132.
The method can further include arranging a first air manipulating member 190 radially between the first tip segment 132 and the first hub segment 142 and configured to manipulate at least a portion of the incoming fan exit air 15 flowing over the leading edge portion 131, and arranging at least one actuation assembly 170 relative to the first tip segment 132 configured to selectively rotate the first tip segment 132 about the leading edge pitch axis 139 to a first pitch angle relative to the incoming fan exit air 15 and configured to selectively rotate the first hub segment 142 independent of the first tip segment 132 about the leading edge pitch axis 139 to a second pitch angle relative to the incoming fan exit air 15.
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. Moreover, each of the embodiments described herein, including the specific features and characteristics of each embodiment, may be combined with other embodiments as would be understood by one of ordinary skill in the art.
This application claims the benefit under 35 U.S.C. § 119(e) of U.S. Provisional Application Ser. No. 63/452,876, filed on Mar. 17, 2023, the entire disclosure of which is incorporated herein by reference.
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.
| Number | Date | Country | |
|---|---|---|---|
| 63452876 | Mar 2023 | US |
