End seal device for a high-lift device of an aircraft

An end seal device for a high-lift device on an airfoil leading edge of an airfoil includes an end seal body configured to be coupled to the airfoil and having a seal body spanwise portion and a seal end. The end seal body is configured to be in a seal extended position when the high-lift device is in a device extended position. The seal body spanwise portion is disposed adjacent to the aircraft body or the airfoil leading edge and the seal end is disposed adjacent to a device end of the high-lift device when the end seal body is in the seal extended position and the high-lift device is in the device extended position. The end seal body in the seal extended position fills a discontinuity otherwise occurring between the device end and the aircraft body or airfoil leading edge if the end seal body were omitted.

FIELD

The present disclosure relates generally to aircraft configurations and, more particularly, to an end seal device for mitigating a vortex generated by a high-lift device of an aircraft.

BACKGROUND

Many aircraft include high-lift devices coupled to the wings for improving the aerodynamic performance of the aircraft. Such high-lift devices may be extended during certain phases of flight to alter the lift characteristics of the wings. For example, an aircraft may have leading edge slats or Krueger flaps that may be extended from the wing leading edge during takeoff, approach, and/or landing to increase the area and camber of the wings to thereby improve the wing lift characteristics.

When a high-lift device is in the extended position, one or both of the opposing device ends of the high-lift device may be exposed to oncoming airflow. The flow of air over a device end may result in the formation of a vortex that extends aftwardly over the wings. For an aircraft that has engines (e.g., turbine engines) located aft of the wings, such a vortex may affect the air entering the engine inlet. In addition, such a vortex may impinge on one or more tail surfaces which may be undesirable from a structural standpoint and/or from a stability and control standpoint. Furthermore, the airflow over the device ends may affect the maximum lift coefficient of the aircraft.

As can be seen, there exists a need in the art for a device and method for mitigating or preventing the occurrence of vortices that may be generated by high-lift devices in the extended position. The device and method also preferably enhance the maximum lift coefficient of the aircraft when the high-lift devices are in the extended position.

SUMMARY

The above-noted needs associated with high-lift devices are specifically addressed by the present disclosure which provides an end seal device for a high-lift device on an airfoil leading edge of an airfoil. The end seal device includes an end seal body configured to be coupled to the airfoil and having a seal body spanwise portion and a seal end. The end seal body is configured to be in a seal extended position when the high-lift device is in a device extended position. The seal body spanwise portion is disposed adjacent to the aircraft body or the airfoil leading edge and the seal end is disposed adjacent to a device end of the high-lift device when the end seal body is in the seal extended position and the high-lift device is in the device extended position. The end seal body in the seal extended position fills a discontinuity otherwise occurring between the device end and the aircraft body or airfoil leading edge if the end seal body were omitted.

Also disclosed is an aircraft having at least one airfoil having a high-lift device on an airfoil leading edge. The aircraft includes an end seal device having an end seal body configured to be coupled to the airfoil and having a seal body spanwise portion and a seal end. The end seal body is configured to be in a seal extended position when the high-lift device is in a device extended position. The seal body spanwise portion is disposed adjacent to the aircraft body or the airfoil leading edge and the seal end is disposed adjacent to a device end of the high-lift device when the end seal body is in the seal extended position and the high-lift device is in the device extended position. The end seal body in the seal extended position fills a discontinuity otherwise occurring between the device end and the aircraft body or airfoil leading edge if the end seal body were omitted.

In addition, disclosed is a method of improving the performance of an aircraft having a high-lift device coupled to an airfoil. The method includes passing an airflow over an end seal body located adjacent to a device end of the high-lift device in a device extended position. The end seal body is in a seal extended position and fills a discontinuity otherwise occurring between the device end and the aircraft body or airfoil leading edge if the end seal body were omitted. The method further includes mitigating, using the end seal device, a vortex otherwise generated by the airflow due to the discontinuity.

DETAILED DESCRIPTION

Referring now to the drawings wherein the showings are for purposes of illustrating preferred and various embodiments of the disclosure, shown inFIG. 1is a perspective view of an example of a blended wing body aircraft106having an aircraft body108and a pair of wings128. The wings128may include one or more trailing edge devices126such as trailing edge flaps and ailerons. In addition, the wings128may each include a wing tip device130such as a winglet (not shown). The blended wing body aircraft106may further include one or more tail surfaces132such as vertical tail surfaces or outwardly-canted tail surfaces. In addition, the blended wing body aircraft106may include propulsion units such as a pair of turbine engines110located above the aircraft body108at the aft end of the aircraft100. Each one of the wings128includes one or more high-lift devices200which are shown in a device retracted position224on the airfoil leading edge118of the wings128. The high-lift devices200may be movable between a device retracted position224and a device extended position226.

Referring toFIG. 2, shown is the blended wing body aircraft106in a configuration in which each one of the high-lift devices200has been moved from the device retracted position224(FIG. 1) to the device extended position226. Also shown are vortices302emanating from the device end222of the respective high-lift devices200in the device retracted position. Each vortex is generated as a result of a discontinuity300between the device end222and the laterally-adjacent portion of the airfoil leading edge118and/or aircraft body108. For the flight condition of the aircraft inFIG. 2, the vortices302extend afterwardly from the device end222along a path that may result in the vortices302distorting the airflow into the engine inlet112of the turbine engines110.

FIGS. 3-4illustrates the aircraft100in a flight condition that results in the vortices302extending along a path that impinges on the tail surfaces (e.g., vertical tails136) of the aircraft100and which may be undesirable from a structural standpoint. For example, the tail surfaces may be required to handle increased aerodynamic loads due to impingement by the vortices302, and resulting in a weight penalty due to an increase in the structural mass of the tail surfaces. The vortices302may also be undesirable from a stability and control standpoint. For example, vortices302impinging on the vertical tails136and corresponding rudders (not shown) may affect yaw control capability (e.g., rudder authority) of the aircraft100in a region of the design envelope where yaw control power may be reduced. Designing the aircraft100such that the vertical tails136are at a location that avoids the vortices302may not be feasible for weight and/or aerodynamic reasons. Reducing the span of the high-lift devices200as a means to reposition the device ends222and corresponding vortices302to a more outboard location may also not be feasible due to the undesirable reduction in maximum lift coefficient that may result from a reduction in the span of the high-lift devices200.

FIG. 5is a magnified view of the inboard end of a high-lift device200ofFIGS. 1-4configured as a leading edge slat202and shown in the device extended position226. Also shown inFIG. 5is a discontinuity300that is formed between the device end222of the leading edge slat202and the laterally-adjacent portion of the airfoil leading edge118and/or aircraft body108of the aircraft100when the leading edge slat202is in the device extended position226. The discontinuity300may be a step-like notch formed between the device end222and the laterally-adjacent portion of the airfoil leading edge118and/or aircraft body108. At the discontinuity300, the device end222may be exposed to oncoming airflow and which may result in the formation of a vortex302emanating from the device end222. As mentioned above, the vortex302may extend aftwardly over the airfoil114and may distort airflow at other locations on or near the aircraft100. For example, during certain combinations of flight conditions such as at certain angles of attack and/or during a sideslip of the aircraft100, a vortex302may disrupt or distort the airflow into an engine inlet112of a turbine engine110as shown inFIG. 2, or the vortex302may impinge on a tail surface132as shown inFIGS. 3-4and described above. In addition, the discontinuity300between the device end222and the airfoil leading edge118or aircraft body108may reduce the maximum lift coefficient of the aircraft100which may affect the takeoff speed and/or landing speed of the aircraft100.

FIG. 6is a sectional view of the wing128illustrating the leading edge slat202in the device extended position226and showing an example of a device actuation system232of the leading edge slat202. The device actuation system232may include one or more arcuate guide tracks238. Each guide track238may be supported by one or more guide rollers242mounted to the airfoil leading edge118. Each guide track238may include a track forward end240coupled to the leading edge slat202. The device actuator234may be configured as a torque tube (not shown) or an electric motor (not shown) having a pinion gear236for engaging teeth (not shown) of the guide track238such that rotation of the pinion gear236causes movement of the guide track238which, in turn, causes movement of leading edge slat202between the device retracted position224and the device extended position226.

FIG. 7shows an example of a blended wing body aircraft106having a presently-disclosed end seal device400installed on each one of the wings128on the inboard sides of the leading edge slats202. In the present disclosure, each end seal device400includes an end seal body402that is couplable to an airfoil114such as the wing128of a blended wing body aircraft106. The end seal body402is configured to be in a seal retracted position420when the high-lift device200is in the device retracted position224, and configured to be in the seal extended position422(FIG. 13) when the high-lift device200is in the device extended position226(FIG. 13). For example, the end seal device400may include a seal actuator434(FIG. 11) configured to transition the end seal body402between the seal retracted position420and the seal extended position422. In some examples, the end seal body402may be transitioned between the seal retracted position420and the seal extended position422independent of the transition of the high-lift device200between the device retracted position224and the device extended position226. In this regard, the end seal device400may be provided in a configuration in which the end seal body402is configured to be non-coupled to the high-lift device200such that the end seal body402moves independently of the high-lift device200.

FIG. 8is a magnified view of a portion of the blended wing body aircraft106showing an example of an end seal body402in an embodiment configured to be rotated about a seal pivot axis442at a pivot end440of the end seal body402. As described in greater detail below, the end seal body402may be rotated about the seal pivot axis442for moving the end seal body402between the seal retracted position420and a seal extended position422(FIG. 13) for filling the discontinuity300(FIG. 5) otherwise occurring between the device end222and the laterally-adjacent portion of the airfoil leading edge118and/or aircraft body108of the aircraft100. Advantageously, in any one of the end seal device400embodiments disclosed herein, the end seal body402may fill the discontinuity300and thereby forms a smooth, non-abrupt transition between the device end222and the portion of the airfoil leading edge118and/or aircraft body108located laterally adjacent to the device end222.

As mentioned above, the end seal device400may mitigate or prevent the disruption of the airflow that may otherwise occur due to the discontinuity300. In this regard, the end seal body402may mitigate or prevent the formation of a vortex302(FIGS. 2 and 5) that may otherwise be generated due to exposure of the device end222to oncoming airflow. Mitigation or prevention of the vortices302may reduce or avoid impingement of such vortices302on one or more tail surfaces132(e.g., vertical tails136) of an aircraft100(e.g.,FIGS. 3-4) which may reduce or avoid undesirable buffeting on the tail surfaces132. The end seal body402may optionally be configured to increase the maximum lift coefficient of the aircraft100relative to the maximum lift coefficient of the same aircraft without end seal devices. In one embodiment, the end seal body402may be provided with a non-lifting shape. For a new aircraft design, the end seal devices400may be designed to mitigate or prevent the formation of vortices302that may otherwise affect the engines (e.g., turbine engines110), the tail surfaces132(e.g., vertical tails136), and which may also enhance the maximum lift coefficient of the aircraft100.

InFIG. 8, the end seal body402has a seal body spanwise portion404which defines a seal length406of the end seal body402. The end seal body402also has a seal body leading edge408and a seal body trailing edge410. In addition, the end seal body402has a seal end412configured to be disposed adjacent to the device end222of a high-lift device200at least when the end seal body402and the high-lift device200are respectively in the seal extended position422(FIG. 13) and the device extended position226(FIG. 13). The end seal body402has a seal width418that be measured along a direction locally perpendicular to the seal body leading edge408. In the example shown, the end seal body402may have the shape of an elongated triangle in which the seal width418generally tapers from the seal end412of the end seal body402to the pivot end440of the end seal body402.

In any one of the end seal device examples disclosed herein, the end seal body402may have an aspect ratio of seal length406to seal width418of no less than 1. For example, the end seal body402may have an aspect ratio of at least 2. Providing the end seal body402at an aspect ratio of no less than 1 may result in a relatively smooth or non-abrupt transition in the spanwise profile of the airfoil114when the high-lift device200is in the extended position. However, in some examples, the end seal body402may have an aspect ratio of less than 1, and which may be capable of mitigating or preventing the formation of vortices302that may otherwise emanate from the device end222of a high-lift device200.

FIG. 9shows the leading edge slat202in a device retracted position224. As mentioned above, the leading edge slat202may be moved to the device extended position226(FIG. 14) by means of a device actuation system232. The device actuation system232may move the leading edge slat202forwardly and downwardly along the airfoil upper surface120from the device retracted position224to the device extended position226. However, the leading edge slat202may be actuated by any one a variety of means for movement between the device retracted position224and the device extended position226(FIG. 14). The high-lift device200is not limited to being configured as a leading edge slat202, and may be provided in other configurations described below such as a Krueger flap204(FIGS. 34-35), a morphing leading edge206(FIGS. 40-47), or other device configurations.

FIG. 10shows a cross-section of the end seal body402in the seal retracted position420at a location generally midway between the seal end412(FIG. 8) and the pivot end440FIG. 8) of the end seal body402.FIG. 11shows a cross-section of the end seal body402at the seal pivot axis442and illustrating an example of a seal actuation system432for rotatably moving the end seal body402between the seal retracted position420and the seal extended position422, as described in greater detail below. At any location along the seal length406, the end seal body402may have a seal outer mold line424having a contour that is complementary to (e.g., substantially matches) and/or which generally conforms to the contour of the airfoil outer mold line124when the end seal body402is in the seal retracted position420.

Referring toFIG. 12, shown is the blended wing body aircraft106and the end seal body402on each wing128moved to the seal extended position422and also showing the high-lift devices200(e.g., leading edge slats202) in the device extended position226. Although the aircraft100includes end seal devices400only on the inboard side of each high-lift device200, an aircraft100may include end seal devices400on both the inboard side and the outboard side of one or more high-lift devices200. In a still further embodiment not shown, an aircraft100may include end seal devices400only on the outboard side of one or more high-lift devices200of the aircraft100.

FIG. 13is a magnified view of a portion of the blended wing body aircraft106showing the high-lift device200(e.g., leading edge slat) in the device extended position226after being moved from the device retracted position224shown in phantom lines. The end seal body402is shown rotated about the seal pivot axis442into the seal extended position422. The seal end412is shown disposed adjacent to the device end222of the high-lift device200. In some examples, the seal end412may be configured to be in abutting and/or contacting relation to the device end222when the end seal body402is in the seal extended position422and the high-lift device200is in the device extended position226. The end seal body402extends between the device end222and the portion of the airfoil leading edge118laterally adjacent to the device end222and thereby fills a discontinuity300(FIG. 3) that would otherwise occur between the device end222and the laterally adjacent portion of the airfoil leading edge118and/or aircraft body108(e.g., fuselage104) of the aircraft100if the end seal body402were omitted.

InFIG. 13, the high-lift device200in the device extended position226has a device outer mold line220which may be defined by a device upper surface228and optionally by a device lower surface (not shown). The device outer mold line220has a contour. The end seal body402in the seal extended position422has a seal outer mold line424which may be defined by a seal upper surface426and a seal lower surface (not shown). The seal outer mold line424has a contour. In any one of the end seal device embodiments disclosed herein, the contour of the end seal body402in the seal extended position422at a location of the seal end412may be complementary to and/or substantially matches the contour of the high-lift device200in the device extended position226at the location of the device end222. In one example, the contour of the seal outer mold line at the seal end412may result in a maximum height mismatch of no greater than 0.25 inch (6.35 mm) between the contour at the seal end412and the contour at the device end222.

FIG. 14is a sectional view of the airfoil114and the high-lift device200(e.g., leading edge slat) in the device extended position226. The high-lift device200may be moved from the device retracted position224(FIG. 9) to the device extended position226via the above-described device actuation system232. As mentioned above, the contour of the end seal body402at the seal end412(FIG. 13) may be substantially similar to the contour of the high-lift device200at the device end222(FIG. 13), at least when the end seal body402is in the seal extended position422and the high-lift device200is in the device extended position226.

FIG. 15shows the end seal body402in the seal extended position422at a location approximately midway between the seal end412and the pivot end440(FIG. 13). In some examples, the end seal body402may be configured such that the seal body trailing edge410is maintained in sealing engagement with the airfoil upper surface120of the airfoil leading edge118at least when the end seal body402is in the seal extended position422as shown inFIG. 13. Maintaining sealing engagement between the seal body trailing edge410and the airfoil upper surface120may prevent airflow between the end seal body402and the airfoil114which may otherwise adversely affect the aerodynamics of the airfoil114. In some examples, the seal body trailing edge410may be maintained in sealing engagement with the airfoil upper surface120during movement of the end seal body402between the seal retracted position420(FIG. 8) and the seal extended position422(FIG. 13).

FIG. 16shows the end seal body402at the seal pivot axis442when the end seal body402is in the seal extended position422. At the seal pivot axis442and at any other location along the seal body spanwise portion404, the contour of the end seal body402may be complementary to the contour of the airfoil outer mold line124.

FIG. 17shows an example of a seal actuation system432for rotating the end seal body402between the seal retracted position420(FIG. 13) and the seal extended position422(FIG. 13). In the example shown, the seal actuation system432is configured as a rotation mechanism436having a seal actuator434such as an electromechanical actuator or electric motor mounted to or within the airfoil leading edge118. The rotation mechanism436may include a shaft438that is coincident with the seal pivot axis442and which is rotatably driven by the seal actuator434. The pivot end440of the end seal body402may be fixedly coupled to the shaft438for rotating the end seal body402between the seal retracted position420to the seal extended position422. The seal pivot axis442and the shaft438may be oriented in a manner such that the end seal body402in the seal retracted position420(FIG. 9) nests against the airfoil upper surface120, and such that the seal end412(FIG. 13) of the end seal body402in the seal extended position422(FIG. 13) is located complementary to the device end222(FIG. 13) of the high-lift device200(FIG. 13) in the device extended position226.

In an embodiment not shown, the seal actuation system may alternatively be configured as a linear actuation system (not shown) located proximate the seal end412and configured to rotate the end seal body402about a simple pivot (not shown) at the pivot end440. Such a linear actuation system may include a guide track (not shown) or a drive screw (not shown) having one end coupled to the end seal body402proximate the seal end412. The linear actuation system may also include a seal actuator (not shown) such as rotary actuator or a linear actuator that may be operatively coupled to the guide track or drive screw for moving the seal end412of the end seal body402between the seal retracted position420and the seal extended position422. Such a linear actuation system may be provided in an electro-mechanical configuration, a hydraulic configuration, or a pneumatic configuration.

In any one of the end seal device400embodiments disclosed herein, the seal actuator434may be a rotary actuator or a linear actuator and may be configured as a seal motor such as a servo motor, a brushless DC motor, a stepper motor, or other motor configurations. Alternatively, the seal actuator434may be a hydraulic actuator that may be coupled to the hydraulic flight control system (not shown) of the aircraft100. In still further embodiments, the seal actuator434may be a pneumatic actuator. InFIG. 17, the rotation mechanism436may be configured to move the end seal body402in a manner such that the seal body trailing edge410(FIG. 13) is maintained in contact with the airfoil upper surface120(FIG. 13) at least when the end seal body402is in the seal extended position422and, optionally, also during movement of the end seal body402between the seal retracted position420(FIG. 13) and the seal extended position422. However, in an example not shown, the end seal body402may be configured such that a gap429(e.g.,FIG. 43) occurs between the seal body trailing edge410and the airfoil upper surface120when the end seal body402is rotated into the seal extended position422.

FIG. 18is a sectional view of an interface between the device end222of a high-lift device200and the seal end412of an end seal body402. The end seal device400may include an interface sealing element414located between the seal end412and the device end222of the high-lift device200and which may be coupled (e.g., mechanically fastened, adhesively bonded, etc.) to the seal end412and/or to the device end222. The interface sealing element414may reduce or prevent airflow between the seal end412and the device end222at least when the end seal device400and the high-lift device200are respectively in the seal extended position422and the device extended position226. In an embodiment, the interface sealing element414may be a non-load-carrying component formed of a resiliently compressible material such as foam rubber or other resiliently compressible and/or elastomeric material. In other embodiments, the interface sealing element414may be configured as a bulb seal or other seal configuration. The interface sealing element414may be fixedly coupled to the seal end412or to the device end222for configurations in which the end seal body402and the high-lift device200are extended and retracted independently of each other and/or for configurations in which the end seal body402and the high-lift device200are extended and/or retracted at different times and/or at different rates. For configurations in which the end seal body402and the high-lift device200are extended and/or retracted in unison, the interface sealing element414may be fixedly coupled to both the seal end412and the device end222.

Referring toFIGS. 19-32, shown inFIG. 19is a top view of a blended wing body aircraft106having high-lift devices200configured as leading edge slats202in a device extended position226. Also shown are end seal devices400in the seal extended position422and located on the inboard side of each one of the high-lift devices200.FIG. 20shows an example of an end seal body402configured for spanwise telescoping from a seal retracted position420to a seal extended position422(FIG. 24) as described below. The end seal body402is in the seal retracted position420and contained within the high-lift device200in the device retracted position224.FIG. 21is a sectional view of the airfoil114ofFIG. 20showing an example of the end seal body402contained within high-lift device200in the device retracted position224. The end seal body402has a cross-sectional shape that may be complementary to and/or substantially similar to the cross-sectional shape of the interior of the high-lift device200. The end seal body402may be hollow or the end seal body402may have a non-hollow cross section.

FIG. 22shows the high-lift device200after movement from the device retracted position224(shown in phantom lines) to the device extended position226. The end seal body402in the seal retracted position420may be fully contained within the interior of the high-lift device200at a location proximate the device end222.FIG. 23is a sectional view of the end seal body402contained within the high-lift device200which is shown in the device extended position226.

FIG. 24shows the high-lift device200in the device extended position226and the end seal body402in the seal extended position422and telescoping out of the device end222of the high-lift device200. The end seal body402may be configured to be translated from the seal retracted position420(FIG. 22) to the seal extended position422by means of spanwise telescoping of the end seal body402. In this regard, the end seal body402may move along a spanwise direction of the high-lift device200and may protrude out the device end222.FIG. 25is a sectional view of the airfoil114showing the end seal body402in the seal extended position422. During spanwise telescoping, at least a portion of the end seal body402may move out of the device end222printFIG. 24) of the high-lift device200. The end seal body402may move in a spanwise direction until the seal body spanwise portion404reaches the seal extended position422which may be described as the point at which seal body spanwise portion404is in contact with a laterally adjacent portion of the airfoil leading edge118or aircraft body108of the aircraft100.

FIG. 26shows the seal body trailing edge410in contact with the airfoil upper surface120of the airfoil114. In some examples, the end seal body402may translate in a spanwise direction until the seal body trailing edge410comes into contact with the airfoil leading edge118and/or the aircraft body108(FIG. 24) of the aircraft100. For telescoping movement, the end seal body402may be fully contained within the high-lift device200when the end seal body402is in the seal retracted position420, and a portion of the end seal body402may be contained within the high-lift device200when the end seal body402is in the seal extended position422.

FIG. 27shows the seal body trailing edge410having a gap sealing element430installed along an underside of the seal body spanwise portion404of the end seal body402for sealing a gap429(FIG. 43) otherwise occurring between the seal body spanwise portion404and the airfoil upper surface120, and thereby preventing airflow between the seal body spanwise portion404and the airfoil upper surface120. The gap sealing element430may be included with end seal devices400for which the high-lift device200(e.g., leading edge slat202) in the device extended position226(FIG. 42) forms a gap429(FIG. 42) between the trailing edge of the high-lift device200and the airfoil upper surface120as shown inFIG. 42and described below. InFIG. 27, the gap sealing element430may be a strip of resiliently compressible material or the gap sealing element430may be formed in an extruded shape such as a bulb shape. The gap seal element may be coupled to the seal body spanwise portion404via adhesive bonding, mechanical fastening, or other attachment means. The gap sealing element430may be located proximate the seal body trailing edge410and may seal the end seal body402to the airfoil upper surface120and may prevent airflow from the airfoil lower surface122(FIG. 26) to the airfoil upper surface120, or vice versa, at least when the end seal body402is in the seal extended position422.

FIG. 28shows an example of a seal actuation system432configured as a telescoping actuation mechanism444for spanwise movement of the end seal body402(FIG. 24) between the seal extended position422(FIG. 22) and the seal retracted position420(FIG. 24). In the example shown, the telescoping actuation mechanism444may include a seal actuator434such as an electric motor mounted to contained or within the high-lift device200. The telescoping actuation mechanism444may include a rack and pinion assembly446for linearly translating the end seal body402between the seal extended position422and the seal retracted position420. Alternatively, the telescoping actuation mechanism444may include a screw drive assembly (not shown) having a threaded shaft (not shown) rotatably driven by the seal actuator434(e.g., electric motor) and to which the end seal body402may be engaged by a nut (not shown) that may be threadably mounted on the threaded shaft. The seal end412may be operatively coupled to the nut such that rotation of the threaded shaft by the seal actuator434is converted into spanwise translation of the end seal body402between the seal retracted position420and the seal extended position422. The telescoping actuation mechanism444such as the rack and pinion assembly446or screw drive assembly (not shown) may be hydraulically actuated or pneumatically actuated. The telescoping actuation mechanism444may optionally be configured as a linear actuator of electric, hydraulic, or pneumatic type.

FIG. 29is a magnified view of a portion of a blended wing body aircraft106showing an example of the end seal device400in a morphing configuration. The high-lift device200is shown in the device retracted position224, and may be configured as a leading edge slat202(FIG. 9), a Krueger flap204(FIGS. 35-38), a morphing leading edge206(FIGS. 44-49) or other type of high-lift device200. In the morphing configuration, the end seal body402comprises a portion of the airfoil leading edge118or aircraft body108that is laterally adjacent to the device end222of the high-lift device200. In this regard, the laterally adjacent portion of the airfoil leading edge118or aircraft body108is configured to function as the end seal body402and morph between the seal retracted position420(FIGS. 29-30) and the seal extended position422(FIGS. 31-32). The end seal body402(e.g., the laterally adjacent portion of the airfoil leading edge118or aircraft body108) may include a morphing structure (not shown) and/or may be constructed of morphable material (not shown) at least within the generally triangularly-shaped region bounded by the seal body trailing edge410(shown as a phantom line) and the seal end412.

In the present disclosure, morphable structure and/or morphable material may be described as structure or material that allows the end seal body402to be morphed between the seal retracted position420and the seal extended position422while providing the strength characteristics and/or stiffness characteristics required for supporting the end seal body402under aerodynamic and/or structural loading. An example of a morphable structure includes the plurality of morphing actuators214and links212that may be coupled to a resiliently flexible skin of a morphing leading edge206as shown inFIG. 49and described below. However, a morphable structure may be provided in any number of configurations and is not limited to an arrangement of morphing actuators214and links212. An example of a morphable material may include the above-mentioned flexible skin which may be formed of metallic material (e.g., titanium, steel) and/or non-metallic material such as fiber-reinforced polymer matrix material such as composite material (e.g., graphite-epoxy). Alternatively or additionally, an end seal device400in a morphing configuration may include a morphing actuation mechanism450operatively coupled to an end seal body402that may be formed of a flexible and resiliently stretchable skin (not shown) supported by a resiliently flexible lining or core (not shown) having strength and stiffness characteristics capable of supporting the end seal body402under aerodynamic loading in both the seal retracted position420and seal extended position422.

FIG. 30is a sectional view ofFIG. 29showing an example of a morphing actuation mechanism450for actuating the end seal body402(e.g., the laterally adjacent portion of the airfoil leading edge118or aircraft body108) between the seal retracted position420and the seal extended position422(FIGS. 31-32). In the example shown, the morphing actuation mechanism450includes at least one morphing actuator214which is configured as a push-pull actuator mounted to and/or within the airfoil leading edge118. One end of the morphing actuator214may be coupled to a spar116of the airfoil114, and an opposite end of the morphing actuator214may be coupled to an interior of the skin208of the end seal body402such that retraction and extension of the morphing actuator214causes morphing of the end seal body402between the seal retracted position420and the seal extended position422(FIGS. 31-32).

FIG. 31shows the portion of the blended wing body aircraft106ofFIG. 29illustrating the high-lift device200in the device extended position226. Also shown is the end seal body402after being morphed into the seal extended position422. In the seal extended position422, the end seal body402fills a discontinuity300(e.g.,FIG. 5) that would otherwise occur between the device end222and the laterally adjacent portion of the airfoil leading edge118or aircraft body108. When morphed into the seal extended position422, the contour of the end seal body402at the location of the seal end412may be complementary to and/or may substantially match the contour of the device end222of the high-lift device200in the device extended position226.

FIG. 32is a sectional view ofFIG. 31showing the end seal body402after being morphed by the morphing actuator214into the seal extended position422. The skin208and/or internal supporting structure (not shown) of the end seal body402may be configured to stretch during morphing from the seal retracted position420to the seal extended position422, and may be configured to return to the original unstretched shape of the skin208when the morphing actuator214morphs the end seal body402back to the seal retracted position420. Although shown as having a single morphing actuator214located proximate the seal end412, the morphing actuation mechanism450may include any number of any one or more of a variety of different types of actuators (e.g., rotary, linear, electro-mechanical, hydraulic, pneumatic, etc.) mounted at one or more locations along the length of the end seal body402.

AlthoughFIGS. 29-32illustrate the end seal body402in the context of a blended wing body aircraft106, the morphing configuration of the end seal body402may be implemented on any one of a variety of different types of aircraft such as the tube-and-wing aircraft102shown inFIGS. 33-34and described below. In addition, the end seal body402is not limited to morphing from a laterally adjacent portion of an airfoil leading edge118, and may alternatively be configured to morph from a laterally adjacent portion of an aircraft body108. Although not shown, the seal end412of the end seal body402in the morphing configuration may be coupled to the device end222of the high-lift device200(e.g.,FIG. 18) for configurations in which the high-lift device200and the end seal body402move in unison with each other. Alternatively, the end seal body402in the morphing configuration may be non-coupled to the high-lift device200such that the end seal body402may move independently of the high-lift device200.

Advantageously, the morphing configuration (FIGS. 29-32) of the end seal body402may reduce or avoid the occurrence of sharp or abrupt changes in the surface contour of the end seal body402along the seal body trailing edge410at the interface with the airfoil upper surface120and at the interface with the airfoil lower surface122. For example, in both the seal retracted position420(FIG. 30) and the seal extended position422(FIG. 32), the surface of the end seal body402at the seal upper surface426and at the seal lower surface428may remain tangent respectively to the airfoil upper surface120and airfoil lower surface122at the seal body trailing edge410. By avoiding sharp or abrupt changes in the surface of the airfoil114when the end seal body402is in the seal retracted position420and seal extended position422, disruption of the airflow over the airfoil114may be avoided which advantageously may promote laminar flow over the airfoil114at high angles of attack.

Referring toFIGS. 33-34, shown is an example of a tube-and-wing aircraft102that may have one or more of the presently-disclosed end seal devices400.FIG. 33shows the tube-and-wing aircraft102having a fuselage104and a pair of wings128. In the present disclosure, the fuselage104of a tube-and-wing aircraft102comprises the aircraft body108. The fuselage104may have a tubular shape. The tube-and-wing aircraft102further includes tail surfaces132such as a horizontal tail134and a vertical tail136, any one of which may include one or more end seal devices400. The wings128of the tube-and-wing aircraft102may include one or more trailing edge devices126such as ailerons and flaps. In addition, the wings128may include one or more high-lift devices200which may be in a device retracted position224inFIG. 33. One or more of the high-lift devices200may be movable between a device retracted position224and a device extended position226.FIG. 34shows the tube-and-wing aircraft102in which the high-lift devices200are configured as Krueger flaps204and which are shown in the device extended position226.

FIG. 35shows a portion of a tube-and-wing aircraft102illustrating the Krueger flaps204in a device extended position226. Also shown are end seal devices400mounted on each of opposing device ends222of each Krueger flap204for filling discontinuities300(FIG. 3) that otherwise would occur if the end seal devices400were omitted from the aircraft100.FIG. 36is a front view of the tube-and-wing aircraft102showing one of the Krueger flaps204in the device extended position226. A pair of end seal devices400are located on each of opposing device ends222of the Krueger flap204.FIG. 37is a sectional view of the wing128showing an example of the Krueger flap204after movement from the device retracted position224to the device extended position226. In the device retracted position224, the Krueger flap204may form a portion of the underside of the airfoil leading edge118and may be rotated outwardly and/or downwardly into the device extended position226for increasing the camber and/or the surface area of the wing128. The Krueger flap204may be actuated by a device actuator234which, in the example shown, may be configured as an electro-mechanical actuator, a pneumatic actuator, or a hydraulic actuator that may be coupled to the hydraulic flight control system of the aircraft100.

FIG. 38is a sectional view of an example of an end seal body402in a flap configuration. The end seal body402may be moved into the seal extended position422in a manner similar to the actuation of the Krueger flap204. For example, a forward portion of the end seal body402may be hingedly coupled to the airfoil leading edge118and may be configured to be rotated outwardly and downwardly into the seal extended position422using a relatively small seal actuator434such as an electrical-mechanical actuator, a pneumatic actuator, or a hydraulic actuator.

In any one of the end seal device embodiments disclosed herein, the end seal body402may be configured such that actuation of the high-lift device200between the device retracted position224and the device extended position226also causes the end seal body402to move between the seal retracted position420and the seal extended position422. In the example of the Krueger flap204shown inFIGS. 36-37, the end seal body402may be configured such that the device actuator234moves the end seal body402between the seal retracted position420and seal extended position422in unison with movement of the Krueger flap204between the device retracted position224and the device extended position226.FIG. 39is a sectional view of a portion of the end seal body402and a portion of the high-lift device200and illustrates an arrangement in which the seal end412is rigidly coupled to the device end222. The rigid attachment may include one or more mechanical fasteners416fixedly securing the seal end412to the device end222such that the high-lift device200and the end seal body402move in unison, such as during actuation of the high-lift device200by the device actuator234(FIG. 37).

Referring toFIGS. 40-42, shown inFIG. 40is a portion of a tube-and-wing aircraft102of which the high-lift devices200are configured as leading edge slats202movably coupled to the wing128. The leading edge slats202are shown in a device retracted position224. Also shown are a pair of end seal devices400on opposite sides of each one of the high-lift devices200each having an end seal body402shown in the seal retracted position420. Each one of the end seal bodies402may have a generally triangular shape. The end seal bodies402are located proximate the opposing device ends222of each one of the leading edge slats202.FIG. 41shows the leading edge slats202in the device extended position226. The end seal devices400are each shown in the seal extended position422.

FIG. 42is a sectional view of in airfoil (e.g., a wing128) showing a leading edge slat202in the device extended position226. Similar to the above-described device actuation system232shown inFIG. 4, the leading edge slat202may be actuated by a device actuator234such as a torque tube (not shown) or electric motor (not shown), either of which may have a pinion gear236for engaging teeth (not shown) of an arcuate guide track238. Rotation of the device actuator causes movement of the guide track238for moving the leading edge slat202between the device retracted position224and the device extended position226. In the example, shown, the leading edge slat202is configured to form a gap429between the leading edge slat202and the airfoil upper surface120when the leading edge slat202is in the device extended position226. The gap429may allow air to flow upwardly through the gap and then generally aftwardly to energize the airflow over the airfoil upper surface120and thereby promote the attachment of airflow to the airfoil upper surface120such as at high angles of attack.

FIG. 43is a sectional view taken of the end seal device400in a slat configuration arranged similar to the configuration of the leading edge slat202. The end seal device400may be configured to move between the seal retracted position420and the seal extended position422via chordwise movement of the end seal body402relative to and/or over the airfoil leading edge118. For example, the end seal body402may be configured to move along the airfoil upper surface120generally parallel to the direction of movement of the leading edge slat202. Similar to the above-described gap429formed between the trailing edge of the leading edge slat202and the airfoil upper surface120when the leading edge slat202is in the device extended position226, the end seal device400in the device extended position226may also be configured to form a gap429between the seal body trailing edge410of the seal body spanwise portion404and the airfoil upper surface120. The gap429may allow air to flow upwardly between the seal body spanwise portion404and the airfoil upper surface120and then aftwardly along the airfoil upper surface120to promote the attachment of airflow to the airfoil upper surface120at high angles of attack.

InFIG. 43, the end seal device400may include a chordwise actuation mechanism448including a seal actuator434mounted to the airfoil leading edge118for actuating the end seal body402. The chordwise actuation mechanism448may include at least one arcuate guide track238similar to the guide track238described above for the leading edge slat202. The guide track238for the end seal body402may be supported by one or more guide rollers242mounted to the airfoil leading edge118. As described above, the guide tracks238may include a track forward end240coupled to the end seal body402. The seal actuator434may be configured as an electric motor having a pinion gear236for engaging teeth (not shown) of the guide track238such that rotation of the pinion gear236via the electric motor causes chordwise movement of the end seal body402between the seal retracted position420and the seal extended position422. Alternatively, the seal actuator434may couple to the device actuator234(e.g., torque tube) such that actuation of the leading edge slats202causes simultaneous actuation of the end seal bodies402.

Referring toFIGS. 44-50, shown inFIG. 44is an example of an airfoil114in which a portion of the airfoil leading edge118is configured as a morphing leading edge206which functions as a high-lift device200for the airfoil114. The morphing leading edge206is shown in a device retracted position224inFIG. 44. Advantageously, the morphing leading edge206provides a means for temporarily increasing the camber of the airfoil114while maintaining laminar flow over the airfoil114due to the avoidance of steps, gaps, and/or sharp edges otherwise associated with the deployment of conventional leading edge devices.FIG. 45shows the morphing leading edge206in the device extended position226and which may result in the formation of vortices302emanating from the device ends222of the morphing leading edge206due to exposure of the device ends222to oncoming airflow.

FIG. 46shows the morphing leading edge206in the device extended position226. Also shown is a pair of end seal devices400in the seal retracted position420. Each one of the end seal devices400has an end seal body402that may be contained within the morphing leading edge206at a location proximate the device ends222of the morphing leading edge206.FIG. 47shows the pair of end seal bodies402after being telescopically translated outwardly respectively from the opposing pair of device ends222of the morphing leading edge206.

FIG. 48is a plan view of the airfoil114showing the morphing leading edge206in the device extended position226and also showing the pair of end seal bodies402configured to be translated telescopically out of the device ends222.FIG. 49is a sectional view of the airfoil114showing an example of a linkage system210that may be implemented for morphing the airfoil leading edge118from the device retracted position224to the device extended position226. The linkage system210may include a plurality of links212that may be pivotably coupled at one end to a spar116of the airfoil114and at an opposite end to the skin208that defines the morphing leading edge206. The linkage system210may further include one or more morphing actuators214coupled to the spar116and pivotably connected to one or more of the links212. The links212may be configured such that actuation of the morphing actuator214causes the skin208of the morphing leading edge206to transition between a first shape207that substantially matches the contour of the airfoil outer mold line124when the morphing leading edge206is in the device retracted position, to a second shape209in which the morphing leading edge206is curved or drooped downwardly in the device extended position226.

FIG. 50is a sectional view of the morphing leading edge206showing an example of the end seal body402in the seal extended position422after telescopic movement of the end seal body402out of interior of the morphing leading edge206. In an embodiment, the end seal body402may be telescopically moved out of the device end222(FIG. 48) until the seal end412(FIG. 48) of the end seal body402is aligned with the device end222of the morphing leading edge206. The contour of the end seal body402at the seal end412may substantially match contour of the morphing leading edge206at the device end222when the end seal body402is in the seal extended position422such that airflow is prevented from flowing between the seal end412of the end seal body402and the device end222of the morphing leading edge206.

FIG. 51shows an example of a telescoping actuation mechanism444for spanwise translation of each end seal body402between the seal retracted position420(FIG. 48) and the seal extended position422(FIG. 48). Similar to the above-described example shown inFIG. 28, each telescoping actuation mechanism444may include a seal actuator434having a pinion gear236operatively engaged to a rack and pinion assembly446. Rotation of the pinion gear236via the seal actuator434may result in linear translation of the end seal body402between the seal extended position422and the seal retracted position420. However, the telescoping actuation mechanism444may be provided in an alternative configuration such as a screw drive assembly (not shown).

Referring toFIGS. 52-62, shown are examples of the end seal device400(e.g.,FIGS. 54-55, 59-60) configured to be non-movably fixed in the seal extended position422. Such end seal devices400may be used in combination with high-lift devices200that may also be permanently fixed to the airfoil114in the device extended position226. End seal devices400that are non-movably fixed to the airfoil114may be incapable of being moved to a device retracted position (not shown).

For example,FIGS. 52-53show an airfoil114in which a portion of the airfoil leading edge118is configured as a leading edge cuff218and which functions as a high-lift device200of the airfoil114. As known in the art, a leading edge cuff218may be fixedly incorporated into or installed on an airfoil leading edge118and may have a slightly drooped lower portion resulting in a locally reduced angle of incidence of the airfoil114which may improve the stall characteristics of the aircraft100.FIGS. 52-53illustrate vortices302that may emanate from the device ends222of the leading edge cuff218due to exposure of the device ends222due to oncoming airflow.

FIG. 54shows an example of the airfoil114having an end seal device400(e.g., an end seal body402) located on each of opposing device ends222of the leading edge cuff218. Each end seal device400may be incorporated into or integral with the airfoil114. Alternatively, each end seal device400may be attached to the airfoil114such as via mechanical fastening and/or adhesive bonding or via other means.FIG. 55is a plan view of the airfoil114showing a pair of end seal bodies402which may be fixedly mounted to the airfoil114at each of opposing device ends222of the leading edge cuff218. In an embodiment, each one of the end seal body402may have a semi-conical shape tapering in size from the seal end412to the opposing end of the end seal body402. The contour of each end seal body402at the seal end412may be complementary to the contour at the device end222of the leading edge cuff218.FIG. 56is a sectional view of the device outer mold line220of the leading edge cuff218showing the drooped lower portion of the leading edge cuff218relative to the contour of the airfoil leading edge118.FIG. 57shows the contour of the seal outer mold line424of the end seal body402at the seal end412substantially matching the contour of the device outer mold line220of the leading edge cuff218at the device end222.

Referring toFIGS. 58-62, shown inFIG. 58is an example of an airfoil114having a high-lift device200configured as a fixed slot216mounted on the airfoil leading edge118. Also shown are vortices302that may emanate from the device ends222of the fixed slot216as a result of oncoming airflow impinging on the device ends222.FIG. 59shows the airfoil114having an end seal device400(e.g., an end seal body402) located on each of opposing device ends222of the fixed slot216, and which may advantageously reduce or prevent the formation of vortices302(FIG. 58) otherwise generated as a result of the discontinuity300otherwise occurring at the device ends222.FIG. 60is a plan view of the airfoil114showing the pair of end seal bodies402respectively located on opposing device ends222of the fixed slot216. Similar to the above-described example of the leading edge cuff218(FIG. 52), the end seal bodies402for the fixed slot216may also have a semi-conical shape.

FIG. 61is a sectional view showing an example of the fixed slot216mounted on the airfoil leading edge118.FIG. 62is a sectional view showing the seal outer mold line424of the end seal body402substantially matching the device outer mold line220of the fixed slot216. As mentioned above for the leading edge cuff218, the end seal bodies402for the fixed slot216may be integrally formed with the airfoil114and fixed slot216. Alternatively, the end seal bodies402for the leading edge cuff218may be installed on the airfoil114such as by using mechanical fasteners and/or adhesive bonding. In this regard, in any of the end seal device400embodiments disclosed herein, the end seal devices400may be configured to be assembled during manufacturing of the airfoil114. Alternatively, the end seal devices400may be configured to be installed on an airfoil114as an aftermarket component.

Although the presently-disclosed end seal device400is shown and described in the context of a wing128, the end seal device400may be configured to be included with and/or mounted to any one of a variety of different types of airfoils114and/or lifting surfaces such as a canard, a tail surface132(FIG. 1) such as a horizontal tail134(FIG. 1) or a vertical tail136(FIG. 1), a ruddervator, a wing tip device130(FIG. 1), or any other type of airfoil114and/or lifting surface, and is not limited to being coupled to a wing128of an aircraft100. In addition, although the end seal device400is shown inFIGS. 7, 13, and 19as being mounted to the wings128of a blended wing body aircraft106as described above, the presently-disclosed end seal device400may be mounted to an airfoil114of any one a variety of different types of fixed-wing aircraft including, but not limited to, a tube-and-wing aircraft102as shown inFIGS. 33-34and described above. In addition, the presently-disclosed end seal device400may be mounted to one or more airfoils114of a rotary-wing aircraft, a tilt-wing aircraft, a vertical-takeoff-and-landing (VTOL) aircraft, and any other type of powered or non-powered aircraft.

FIG. 63is a graph plotting angle of attack500versus maximum lift coefficient502(CLmax) of a blended wing body aircraft106(e.g.,FIGS. 2 and 10) during wind tunnel testing. The blended wing body aircraft106has Krueger flaps204in the device extended position226(FIGS. 2 and 12) during the wind tunnel testing. The graph shows two plots of angle of attack500versus maximum lift coefficient502including a plot for a first aircraft configuration504in which end seal devices400were omitted from the blended wing body aircraft106similar to the configuration shown inFIG. 2, and a plot for a second aircraft configuration506in which end seal devices400in the seal extended position422were included with the blended wing body aircraft106similar to the configuration shown inFIG. 12. As can be seen, the second aircraft configuration506with end seal devices400resulted in a significant increase maximum lift coefficient502relative to the first aircraft configuration504from which the end seal devices400were omitted.

Referring toFIGS. 64-69, shown in each figure are portions of a blended wing body aircraft106having Krueger flaps204in a device extended position226. The blended wing body aircraft106was subjected to wind tunnel testing for measuring the effect of end seal devices400on the flowfield at a location upstream of the engine inlets112. The blended wing body aircraft106was oriented such that the wings128were at a positive angle of attack of 20 degrees during measurement of the longitudinal velocity. The longitudinal velocity was measured using particle image velocimetry which allowed for optical visualization of the flowfield. Each one ofFIGS. 64-69includes an insert514that graphically illustrates the velocity measurements according to a legend516of longitudinal velocity located in the lower right-hand corner of each ofFIGS. 64-69. The longitudinal velocity in each legend516is divided into three (3) velocity ranges including low, medium, and high.

InFIGS. 64-65, the longitudinal velocity was measured at a first fuselage station508upstream of the turbine engine110mounted on the right-hand side of the blended wing body aircraft106. InFIG. 64, end seal devices400were omitted from the blended wing body aircraft106in a configuration similar to the configuration ofFIG. 2. The lower left-hand region of the insert514inFIG. 64graphically illustrates a large area of low longitudinal velocity and which indicates the presence of a vortex302(FIG. 3) generated due to the discontinuity300(e.g.,FIG. 3) located between the device end222(FIG. 3) on the inboard side of the Krueger flap204(FIG. 3). InFIG. 65, end seal devices400in the seal extended position422were installed on the inboard side of each one of the Krueger flaps204in a configuration similar to the configuration ofFIG. 12. The insert514inFIG. 65graphically illustrates a relatively large area of high speed longitudinal velocity indicating the absence of a vortex302due to the addition of the end seal devices400.

FIGS. 66-67are views of the blended wing body aircraft106respectively similar toFIGS. 64-65except that the longitudinal velocity was measured at a second fuselage station510located aft of the first fuselage station508. InFIG. 66, end seal devices400were omitted from the blended wing body aircraft106and resulting in a large area of low longitudinal velocity as shown in the lower left-hand region of the insert514and which indicates the presence of a vortex302. In contrast, inFIG. 67, end seal devices400in the seal extended position422were installed on the inboard sides of the Krueger flaps204and resulting in a relatively large area of high speed longitudinal velocity as shown in the insert514and which indicates the absence of a vortex302.

FIGS. 68-69are respectively similar toFIGS. 66-67except that the longitudinal velocity was measured at a third fuselage station512located aft of the second fuselage station510. InFIG. 68, the area of low longitudinal velocity in the insert514is larger in size than in the corresponding insert514ofFIG. 66, indicating an increase in the size (e.g., diameter) of the vortex302at the third fuselage station512relative to the size of the vortex302at the second fuselage station510. In contrast, inFIG. 69, the insert514shows a relatively large area of high speed longitudinal velocity which indicates the absence of a vortex302due to the addition of end seal devices400.

Referring toFIG. 70, shown is a method600of improving the performance of an aircraft100having a high-lift device200coupled to an airfoil114of the aircraft100. The method600may include step602of moving the high-lift device200from a device retracted position224to a device extended position226. For example, the method may include moving a leading edge slat202between a device retracted position224and a device extended position226as shown inFIGS. 9, 14, 20-22, and 40-42and described above. In another example, the method may include moving a Krueger flap204between a device retracted position224and a device extended position226as shown inFIGS. 34-37and described above. In a further example, the method may include actuating a morphing leading edge206between a device retracted position224and a device extended position226as shown inFIGS. 40-47and described above. However, the method may include actuating other types of high-lift devices200between the device retracted position224and the device extended position226, and is not limited to actuating a leading edge slat202, a Krueger flap204, or a morphing leading edge206. In still further examples described below, the high-lift device200may be permanently fixed to the airfoil114in a device extended position226and may be incapable of moving to a device retracted position224.

Step604of the method600may include moving the end seal body402from the seal retracted position420to the seal extended position422. In the seal extended position422, the seal end412of the end seal body402may be aligned with the device end222of the high-lift device200when in the device extended position226. In this regard, the contour at the seal end412may substantially conform to or match the contour of the high-lift device200. In some examples, the method may include moving, using a seal actuator434, the end seal body402between the seal retracted position420and the seal extended position422independent of movement of the high-lift device200between the device retracted position224and the device extended position226. For example, referring toFIGS. 8-9 and 13-14, the step604of moving the end seal body402from the seal retracted position420to the seal extended position422may include rotating the end seal body402about a seal pivot axis442as shown inFIG. 13. Rotation of the end seal body402about the seal pivot axis442may include rotating the end seal body402using a rotation mechanism436as described above. In some examples, the rotation mechanism436may the configured to rotate the end seal body402such that the seal body trailing edge410is maintained in contact with the airfoil upper surface120at least when the end seal body402is in the seal extended position422to prevent airflow therebetween.

Referring toFIGS. 20-28, in a further example, step604of moving the end seal body402from the seal retracted position420to the seal extended position422may include telescopically moving the end seal body402contained in the seal retracted position420within the high-lift device200along a spanwise direction at least partially out of the device end222of the high-lift device200. As described above, the end seal body402may be contained within the high-lift device200in the device retracted position224and/or during deployment of the high-lift device200from the device retracted position224to the device extended position226. The end seal body402may be telescopically moved out of the device end222at least until the seal body spanwise portion404contacts the airfoil leading edge118and/or an aircraft body108of the aircraft100as shown inFIG. 24. Referring toFIG. 28, telescopically moving the end seal body402may be performed using a telescoping actuation mechanism444as described above for linearly translating the end seal body402between the seal retracted position420and the seal extended position422, as described above

Referring toFIGS. 35-39 and 40-43, in a further example, step604of moving the end seal body402from the seal retracted position420to the seal extended position422may include moving the end seal body402in a generally chordwise direction relative to and/or over the airfoil leading edge118such as along the airfoil upper surface120. For examples in which the high-lift devices200are configured as leading edge slats202as shown inFIGS. 40 and 42, movement of the end seal body402may be generally parallel to the direction of movement of the leading edge slat202. In some examples, the step of moving the end seal body402in a generally chordwise direction may include moving the end seal body402using a chordwise actuation mechanism448including a seal actuator434mounted to the airfoil leading edge118. For example, as shown inFIG. 43, the chordwise actuation mechanism448may include an arcuate guide track238and a seal actuator434(e.g., electric motor) for effecting chordwise movement of the end seal body402between the seal retracted position420and the seal extended position422. For examples in which the high-lift devices200are configured as Krueger flaps204as shown inFIGS. 35-37, pivoting movement of the end seal body402(e.g.,FIG. 38) may be performed using a seal actuator434as shown inFIG. 38.

In some examples, step604of moving the end seal body402between the seal retracted position420and the seal extended position422may be performed simultaneously with the movement in step602of the high-lift device200between the device retracted position224and the device extended position226. For example, as shown inFIG. 39, the device end222of a Krueger flap204may be rigidly coupled to the seal end412of the end seal body402such as by using mechanical fasteners416. Actuation of the Krueger flap204by the device actuator234may cause the end seal body402to be actuated in unison with the Krueger flap204. However, in other examples, the end seal body402may be non-coupled to the high-lift device200such that the end seal body402may be moved independently of the high-lift device200. In some examples, the end seal body402may be actuated by a seal actuator434independent of, but simultaneous with, actuation of the high-lift device200by a device actuator234. Step604of moving the end seal body402between the seal retracted position420and the seal extended position422may be performed either before or after movement of the high-lift device200between the device retracted position224and the device extended position226. In still further examples, the timing of the movement of the end seal body402between the seal retracted position420and/or the seal extended position422may at least partially overlap with timing of the movement of the high-lift device200between the device retracted position224and/or the device extended position226.

Step606of the method600includes passing an airflow (e.g., during flight) over an end seal device400located adjacent to a device end222of a high-lift device200in a device extended position226. As described above, the end seal body402in the seal extended position422is configured to fill a discontinuity300(FIG. 3) otherwise occurring between the airfoil leading edge118and the device end222if the end seal body402were omitted. As mentioned above, the seal end412may the in abutting and/or contacting relation to the device end222when the end seal body402is in the seal extended position422and the high-lift device200is in the device extended position226.

Referring briefly toFIG. 18, in some examples, the method may include preventing, using an interface sealing element414, airflow between the seal end412and the device end222at least when the end seal body402and the high-lift device200are respectively in the seal extended position422and the device extended position226. As described above, the interface sealing element414may be a non-load-carrying element that is fixedly coupled to the seal end412and/or to the device end222. The interface sealing element414may be formed of a resiliently compressible material that prevents airflow between the seal end412and the device end222which may otherwise disrupt the airflow and potentially cause the formation of a small vortex302.

Referring briefly toFIGS. 24-27, in some examples, the method may include preventing, using a gap sealing element430, airflow between the seal body spanwise portion404of an end seal body402and the airfoil upper surface120of the airfoil114, at least when the end seal body402is in the seal extended position422. Such airflow between the seal body spanwise portion404and the airfoil upper surface120may disrupt normal airflow over the airfoil114. As mentioned above, the gap sealing element430may extend along the seal body spanwise portion404on the inner surface of the end seal body402and may be coupled to the end seal body402via bonding and/or mechanical fastening. In one example, a gap sealing element430may be included on the slat configuration of the end seal body402as shown inFIGS. 25-27, 41 and 43. The gap sealing element430may seal a gap429(e.g.,FIG. 43) occurring between the seal body spanwise portion404and the airfoil upper surface120, and may be used in conjunction with high-lift devices200configured to form a gap429(FIG. 42) between the high-lift device200and the airfoil upper surface120when the high-lift device is in the device extended position as shown inFIG. 42and described above.

Referring briefly toFIGS. 52-62, in some examples, the high-lift device200may be non-movable and may be permanently fixed in the device extended position226. For example,FIGS. 52-57illustrate a leading edge cuff218that may be permanently fixed in the device extended position226on the airfoil leading edge118.FIGS. 58-62illustrate a fixed slot216that may be permanently fixed in the device extended position226on the airfoil leading edge118. For aircraft100having high-lift devices200that are permanently fixed in the device extended position226, the end seal body402may optionally be fixed in the seal extended position422and may be incapable of being moved into a seal retracted position420. As shown inFIGS. 52-62, such end seal devices400may be integrally formed with or fixedly mounted to the airfoil114and/or to a device end222of a high-lift device200and may thereby fill a discontinuity300that would otherwise occur between the airfoil leading edge118and the device end222of the high-lift device200.

Step608of the method600includes mitigating, using an end seal device400, a vortex302generated by the airflow due to the discontinuity300(FIG. 3) otherwise occurring between the seal end412and the laterally adjacent portion of the airfoil leading edge118and/or aircraft body108. Advantageously, as discussed above and as graphically illustrated inFIGS. 64-69, the end seal body402may fill the discontinuity300and thereby create a smooth, non-abrupt transition between the device end222and the portion of the airfoil leading edge118and/or aircraft body108. By filling the discontinuity300, the end seal body402may prevent the formation of a vortex302. In addition, the end seal body402may prevent or reduce disruption of the airflow that may otherwise occur due to the discontinuity300. As is graphically illustrated inFIG. 63, for an aircraft100having high-lift devices200in a device extended position226, the addition of end seal devices400may result in a significant increase in maximum lift coefficient relative to the maximum lift coefficient of an aircraft100for which the end seal devices400are omitted.

Many modifications and other configurations of the disclosure will come to mind to one skilled in the art, to which this disclosure pertains, having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. The configurations described herein are meant to be illustrative and are not intended to be limiting or exhaustive. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.