The field of the present disclosure generally relates to aeronautical vehicle systems. More particularly, the field of the invention relates to a system and method for altering the shape of an airfoil.
Current aircraft designs utilize a variety of airfoils on wings, horizontal stabilizers, canards, rotor blades, vertical stabilizers, and a variety of other structures consisting primarily of relatively fixed airfoil surfaces. Flying surfaces generally must be optimized for specific applications such as low-speed handling or improved high-speed aerodynamics. Aircraft configured to operate in several performance environments must often adopt airfoil surfaces that provide suitable characteristics in multiple environments. Such a compromise, however, typically diminishes the overall performance of the aircraft, as well as diminishing performance in specific flight conditions.
Conventional configurations often limit modification of the flying surfaces to that which may be achieved by way of mechanical moving surfaces. Mechanical actuators and linkage systems are utilized to effectuate changes in the airfoil surfaces to allow for enhanced low-speed flight and limited autopilot maneuvering. Military aircraft have utilized mechanically swept wings for improved aerodynamics during high speed flight. Although movable airfoil components may have a substantial effect on the aerodynamic flight characteristics of the airfoil, the shapes of the airfoil components generally are fixed. As such, further optimizing airfoils for performance over a larger range of the flight envelope typically requires incorporating additional airfoil components as well as all those certain components necessary to move the additional airfoil components. Including additional moveable airfoil components tends to be unappealing, however, due limited space and weight requirements associated with most aircraft.
Shape adaptive airfoils are an improved approach whereby the configuration of the airfoil may be optimized throughout the flight envelope of the aircraft. Modifying the shape of the airfoil enables the configuration of the airfoil to be optimized over most of the flight conditions of the aircraft. An optimized airfoil may provide better lift characteristics at lower speeds to allow greater take-off weight while providing lower drag at high speed to achieve a greater flight range. Thus, a modifiable airfoil capable of being optimized throughout the flight envelope provides significant improvements to aircraft performance.
A modifiable or adaptive airfoil generally requires a means of actuation. A drawback, however, is that conventional electric or hydraulic actuators tend to be heavy, complex, and difficult to fit within the confines of the adaptive airfoil. Further, conventional actuators generally require electrical signal wires, power wires or hydraulic lines, and complex controllers. Routing of wiring and hydraulic lines tends to be is difficult to accomplish on movable structures, particularly when Fowler action is required. Moreover, conventional actuators often are expensive, custom design items that require long lead times for development to ensure that the actuators meet all strength, deflection, fatigue, and mounting requirements.
What is needed, therefore, is an actuation system configured to modify adaptive airfoils and cooperate with existing flap or slat drive systems and linkage systems.
An apparatus and method are provided for an actuator system for modifying a shape of an airfoil. The actuator system comprises a skin overlap that is disposed on a surface of the airfoil. The skin overlap is configured to allow a first portion of the airfoil to move relative to a second portion of the airfoil. A drive rod is coupled with a bell crank that is pivotally attached to an interior of the first portion of the airfoil. A bumper is configured to push the drive rod during movement of the airfoil, such that the bell crank slides the first portion relative to the second portion, thereby modifying the shape of the airfoil. The actuator system may be coupled with, and driven by, a flap drive system and a linkage system that are configured to extend, deflect, and retract a trailing edge flap of an aircraft. In some embodiments, the actuator system may be configured to cooperate with a slat drive system and a linkage system that are configured to extend a slat of an aircraft. In some embodiments, the actuator system may be configured to cooperate with a hinged airfoil member, such that rotation of the hinged airfoil member pushes the drive rod, thereby effectuating a shape adaptation of the airfoil member. The hinged airfoil member may be comprised of ailerons, horizontal stabilizers, and any of various other generally hinged airfoil members of an aircraft.
In an exemplary embodiment, an actuator system for modifying a shape of an airfoil comprises a skin overlap disposed on a surface of the airfoil and configured to allow a first portion to move relative to a second portion of the airfoil; a drive rod coupled with a mount affixed to an interior of the first portion; and a bumper configured to push the drive rod and the mount during movement of the airfoil, such that the first portion slides relative to the second portion, thereby modifying the shape of the airfoil.
In another exemplary embodiment, the airfoil comprises a trailing edge flap coupled with an aircraft wing, the bumper being mounted to the aircraft wing so as to push the drive rod when the flap is retracted, thereby changing the airfoil from an initial profile to a cambered profile. In another exemplary embodiment, the skin overlap is disposed on an upper surface of the trailing edge flap, and wherein the lower surface of the trailing edge flap is configured to exert a continuous force in opposition to the force exerted by the drive rod while the airfoil is in the cambered profile. In another exemplary embodiment, the skin overlap is disposed on a lower surface of the trailing edge flap, and wherein the upper surface of the trailing edge flap is configured to exert a continuous force in opposition to the force exerted by the drive rod while the airfoil is in the cambered profile. In another exemplary embodiment, the continuous force changes the trailing edge flap from the cambered profile to the initial profile during extending of the trailing edge flap.
In another exemplary embodiment, a bell crank is rotatably attached to an interior member of the airfoil and configured to receive an end of the drive rod, and wherein a pivot is disposed opposite of the drive rod and configured to couple the bell crank to the mount. In another exemplary embodiment, the actuator system is coupled with and driven by a flap drive system and a linkage system configured to extend, deflect, and retract a trailing edge flap of an aircraft. In another exemplary embodiment, the actuator system is configured to cooperate with a slat drive system and a linkage system that are configured to extend a slat of an aircraft. In another exemplary embodiment, the actuator system is configured to couple the drive rod adjacently to hinges of an airfoil member, such that rotation of the airfoil member about the hinges pushes the drive rod, thereby effectuating a shape adaptation of the airfoil member. In another exemplary embodiment, the airfoil member may be comprised of ailerons, horizontal stabilizers, and any of various other generally hinged airfoil members of an aircraft.
In an exemplary embodiment, a method for an actuator system to modify a shape of an airfoil comprises configuring a skin overlap on a surface of the airfoil to allow a first portion to move relative to a second portion of the airfoil; coupling a drive rod with a mount affixed to an interior of the first portion; and positioning a bumper to push the drive rod and the mount during movement of the airfoil, such that the first portion slides relative to the second portion, thereby modifying a profile of the airfoil.
In another exemplary embodiment, coupling comprises attaching a bell crank to an interior member of the airfoil, such that an end of the drive rod is received by the bell crank, and wherein coupling comprises linking the bell crank to the mount by way of a pivot disposed oppositely of the end of the drive rod. In another exemplary embodiment, configuring comprises forming the skin overlap in a lower surface of a tailing edge flap such that a continuous force exerted by the drive rod modifies a camber profile of the trailing edge flap by way of the bell crank and the mount, and wherein an upper surface of the trailing edge flap is configured to exert a continuous force in opposition to the force exerted by the drive rod. In another exemplary embodiment, positioning comprises mounting the bumper near the airfoil, such that the drive rod contacts the bumper during retracting of the airfoil.
In another exemplary embodiment, configuring comprises forming the skin overlap in an upper surface of a trailing edge flap such that a continuous force exerted by the drive rod modifies a camber profile of the trailing edge flap, and wherein a lower surface of the trailing edge flap is configured to exert a continuous force in opposition to the force exerted by the drive rod. In another exemplary embodiment, the method further comprises coupling the actuator system with a flap drive system and a linkage system that are configured to extend, deflect, and retract a trailing edge flap of an aircraft. In another exemplary embodiment, the method further comprises coupling the actuator system with a slat drive system and a linkage system that are configured to extend a slat of an aircraft.
In an exemplary embodiment, an actuator system for modifying a trailing edge portion of a flap of an aircraft wing comprises a drive rod extending from a nose portion of the flap to an interior of the flap; a bell crank rotatably attached to an interior member of the flap and configured to receive an end of the drive rod; a pivot disposed opposite of the drive rod and configured to couple the bell crank to a mount fixed to a lower surface of the trailing edge portion; a skin overlap configured to allow the lower surface of the trailing edge portion to slide adjacently to a lower surface of a remaining portion of the flap under the action of the drive rod; and a bumper disposed within the aircraft wing and configured to exert a continuous force on the drive rod when the flap is moved to a retracted state.
In another exemplary embodiment, the actuator system is configured to cooperate with a flap drive system and a linkage system that are configured to extend, deflect, and retract the flap of the aircraft wing. In another exemplary embodiment, the continuous force maintains a cambered profile of the trailing edge portion when the flap is in the retracted state. In another exemplary embodiment, the continuous force is relieved and the trailing edge portion returns to an initial profile when the flap is extended away from the aircraft wing.
The drawings refer to embodiments of the present disclosure in which:
While the present disclosure is subject to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and will herein be described in detail. The invention should be understood to not be limited to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure.
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure. It will be apparent, however, to one of ordinary skill in the art that the invention disclosed herein may be practiced without these specific details. In other instances, specific numeric references such as “first wing,” may be made. However, the specific numeric reference should not be interpreted as a literal sequential order but rather interpreted that the “first wing” is different than a “second wing.” Thus, the specific details set forth are merely exemplary. The specific details may be varied from and still be contemplated to be within the spirit and scope of the present disclosure. The term “coupled” is defined as meaning connected either directly to the component or indirectly to the component through another component. Further, as used herein, the terms “about,” “approximately,” or “substantially” for any numerical values or ranges indicate a suitable dimensional tolerance that allows the part or collection of components to function for its intended purpose as described herein.
In general, the present disclosure describes an apparatus and method for an actuator system to modify the shape of an adaptive airfoil. The actuator system comprises a skin overlap, or a skin break, disposed on a surface of the airfoil and is configured to allow a first portion to move relative to a second portion of the airfoil. A drive rod is coupled with a mount that is affixed to an interior of the first portion. A bumper is configured to push the drive rod and the mount during retracting of the airfoil, such that the first portion slides relative to the second portion, thereby modifying the shape of the airfoil. In some embodiments, the airfoil may comprise a trailing edge flap coupled with an aircraft wing, and the bumper may be mounted within the aircraft wing so as to push the drive rod when the flap retracts, thereby changing the airfoil from an initial profile to a cambered profile. The actuator system may be configured to cooperate with a flap drive system and a linkage system that are configured to extend, deflect, and retract the tailing edge flap of the aircraft wing.
It should be understood that the illustration of the aircraft 100 in
Moreover, although the illustrative examples for an exemplary embodiment are described with respect to an aircraft, an illustrative embodiment may be applied to other types of platforms. The platform may be, for example, a mobile platform, a stationary platform, a land-based structure, an aquatic-based structure, and a space-based structure. More specifically, the platform, may be a surface ship, a train, a spacecraft, a submarine, an automobile, a power plant, a windmill, a manufacturing facility, a building, and other suitable platforms configured to interact with exterior fluids such as atmospheric air or water.
As shown in
Coupled with a trailing edge of each of the first and second wings 104, 108 are ailerons 144 and trailing edge flaps 148. As will be appreciated, the ailerons 144 enable the pilot to control rolling of the aircraft 100. The trailing edge flaps 148 preferably are of the Fowler variety that enable the pilot to manipulate the performance of the aircraft 100 by altering the camber and cord of the first and second wings 104, 108, as best shown in
Upon comparing the trailing edge flap 148 illustrated in
As shown in
As will be appreciated, the portions of the lower surfaces 176, 216 comprising the skin overlap 212 preferably are in sliding contact, whereby the lower surface 176 passes over the lower surface 216 and extends into the interior of the flap 148. In some embodiments, however, the skin overlap 212 may be comprised of a skin break or a skin gap. It is contemplated, therefore, that in some embodiments, edges of the lower surfaces 176, 216 may not share a sliding relationship, but rather may be moved adjacently to one another so as to allow the mount 208 to pull the trailing edge portion 164 into the cambered profile 224, as described above.
It is contemplated that the bumper 228 may be attached to a variety of structures within the wing 104, such as, by way of non-limiting example, a wing spar, skin overhang, flap track or linkage, or a fitting specifically configured to receive the bumper 228. In some embodiments, however, the bumper 228 may be comprised of any fixed attach point suitable for contacting the drive rod 172, without limitation. Further, the drive rod 172 is not limited to contacting the bumper 228 by way of the rounded end 232. It is envisioned that the bumper 228 and the rounded end 232 may be implemented in a variety of configurations suitable for pushing the drive rod 172 toward the trailing edge portion 164 when the flap 148 is retracted into the wing 104.
As will be recognized, the flexibility of the upper surface 220 operates as a spring, storing elastic potential energy and exerting a continuous force in opposition to the force exerted by the drive rod 172 while the trailing edge portion 164 is in the cambered profile 224. Upon extending the flap 148, as shown in
As will be appreciated, the actuator system 168 need not be limited to the bell crank 180. It is contemplated that any of various structures, or combinations of structures, such as, for example, one or more linkages, may be implemented such that the mount 208 moves desirably when the bumper 228 pushes the drive rod 172. Further, the actuator system 168 is not limited to pulling the trailing edge portion 164 downward into the cambered profile 224, but rather in some embodiments the actuator system 168 may be configured to push the trailing edge portion 164 into an upward cambered profile, without limitation.
Moreover, although in the embodiment of the actuator system 168 illustrated in
During operation of the actuator system 236, when the flap 148 retracts, as discussed in connection with
It should be understood that the actuator system 236 is not to be limited to pushing the trailing edge portion 164 into the cambered profile 224, but rather in some embodiments the drive rod 244 may be configured to pull the mount 248 so as to further compress the skin overlap 240 and draw the trailing edge portion 164 into an upward cambered profile. Further, it should be recognized that the degree to which the camber of the trailing edge portion 164 may be changed is determined, at least in part, by the length of the drive rod 244. As such, the length of the drive rod 244 is not to be limited to specific lengths, nor is the trailing edge portion 164 to be limited to specific cambered profiles, but rather any suitable length of the drive rod 244 may be implemented so as to change the trailing edge portion 164 into any desired cambered profile, without limitation, and without deviating beyond the spirit and scope of the present disclosure.
Moreover, it is contemplated that either of the actuator systems 168, 236 may be coupled with airfoil members other than trailing edge flaps 148, such as, by way of non-limiting example, the ailerons 144, the first horizontal stabilizer 128, the second horizontal stabilizer 132, as well as any of various other generally hinged airfoil members comprising the aircraft 100. For example, in some embodiments, either of the drive rods 172, 244 may be coupled adjacently to hinges of a hinged airfoil member, such that rotation of the airfoil member about the hinges pushes the drive rod, as described herein, thereby effectuating a shape adaptation of the airfoil member.
It is contemplated that the drive rods 172, 244 need not be limited to generally solid, elongate members, as described above, but rather the drive rods 172, 244 may be comprised any of various devices, or combinations of devices, that are suitable for exerting forces on the mounts 208, 248 so as to effectuate shape adaptations of airfoil members, such as the trailing edge flap 148. In some exemplary embodiments, the drive rods 172, 244 may be each comprised of a piston disposed within a sleeve. It is envisioned that the piston may be coupled with the bumper 228, and the sleeve may be coupled with either the bell crank 180 or the mount 248, such that retracting of the airfoil member, or rotating of a hinged airfoil pushes the piston within the sleeve. Once the sleeve prohibits further motion of the piston, the piston and sleeve together effectuate adaptation of the shape of the airfoil member, as described herein.
While the invention has been described in terms of particular variations and illustrative figures, those of ordinary skill in the art will recognize that the invention is not limited to the variations or figures described. In addition, where methods and steps described above indicate certain events occurring in certain order, those of ordinary skill in the art will recognize that the ordering of certain steps may be modified and that such modifications are in accordance with the variations of the invention. Additionally, certain of the steps may be performed concurrently in a parallel process when possible, as well as performed sequentially as described above. To the extent there are variations of the invention, which are within the spirit of the disclosure or equivalent to the inventions found in the claims, it is the intent that this patent will cover those variations as well. Therefore, the present disclosure is to be understood as not limited by the specific embodiments described herein, but only by scope of the appended claims.
This application claims priority to U.S. Provisional Application No. 62/318,132, filed Apr. 4, 2016, titled “Actuator For Adaptive Airfoil,” and incorporated by reference in its entirety herein.
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/US17/25375 | 3/31/2017 | WO | 00 |