The present application claims the priority of German Patent Application No. 10 2005 045 759.2 filed on Sep. 23, 2005, the contents of which are incorporated herein by reference.
The present invention relates to an advanced trailing edge control surface on the wing of an aircraft.
The described device is most sensibly referred to as an advanced trailing edge control surface (ATECS-Advanced Trailing Edge Control Surface) because it has a significantly broader spectrum of applications than the basic mechanical principle of a simple slotted flap due to its kinematics and novel multi-functional control surfaces.
The state of the art includes a large number of trailing wing flap systems, an excerpt of which is initially described below in the form of the representatives most relevant to the present invention. The most relevant representatives of these systems are primarily single-gap flap systems. These flap systems are used as primary as well as secondary flight control and in the form of combined control surfaces. Furthermore, these representatives may be used for roll control, pitch control and for increasing the lift. The two latter-mentioned patents show exemplary options for realizing an adaptive wing that is not designed for an/one “optimal” operating point only.
The simple slotted flap, in principle, consists of a simple hinged support that is defined in space by a pivoting axis. Advantageous technical effects can be achieved if the pivoting axis lies far below the wing profile (U.S. Pat. No. 4,120,470):
The wing surface and the wing curvature are increased when the flap is extended (positive flap value positions) such that the lift increases significantly.
The flap or the control surface is moved into the high-energy air flow such that the lift is additionally increased.
However, a few disadvantageous technical effects occur:
Negative flap value positions are typically not possible because the nose edge of the flap diverges from the enveloping geometry of the wing on the profile underside and significant structural space conflicts arise in the rear spar region of the wing (depending on the position of the pivotal point).
Convergent/divergent air flows with the associated loss of lift and significantly increased drag frequently occur in the gap air flow.
An aerodynamic fairing of the mechanical flap system which lies in the air flow is required, but additional aerodynamic drag is created in this case.
If the pivoting axis lies near the nose edge of the flap (U.S. Pat. No. 2,117,607, U.S. Pat. No. 2,169,416, U.S. Pat. No. 2,276,522, U.S. Pat. No. 2,836,380, U.S. Pat. No. 2,920,844, U.S. Pat. No. 4,015,787, U.S. Pat. No. 4,395,008, U.S. Pat. No. 4,471,927, U.S. Pat. No. 4,962,902, DE1943680, DE19803421A1, FR846337, U.S. Pat. No. 6,601,801), the following advantageous technical effects can be achieved:
Positive and negative flap value positions can be realized with simpler constructions.
This is decisive for primary control surfaces because they typically need to assume positive and negative value positions (elevators/ailerons/rudders). Secondary control surfaces primarily operate as high-lift components of an aircraft and, as such, usually only have one preferred effective direction.
However, this position of the pivotal point results in one decisive disadvantage: the high-energy air flow can no longer flow around the flap. The high-energy air flow around the wing underside has the advantageous technical effect of decisively improving the separation characteristics of the entire wing. This problem is eliminated with a ventilation flap that lies underneath the wing (U.S. Pat. No. 2,117,607). Due to the lower ventilation flap, the high-energy air flow can also flow around a flap with a pivotal point near the leading wing edge. The lower ventilation flap is closed while cruising such that the overall wing profile ensures minimal aerodynamic drag.
The lower ventilation flap of the cited patents is usually designed for positive flap value positions only (U.S. Pat. No. 2,117,607, U.S. Pat. No. 2,169,416). The mechanical connection between the lower ventilation flap and the flap Is either realized with a mechanical geared coupling or with an additional drive.
Other known flap systems (U.S. Pat. No. 6,601,801) feature a lower ventilation flap that is also suitable for negative flap value positions. However, the mechanical system used is relatively complex and comprises a large number of components.
Another known flap system (DE1943680) features a lower and an upper ventilation flap that are suitable for positive and negative flap value positions. One decisive disadvantage of this concept is that the ventilation flaps diverge from the external wing profile contour (drag, noise). This system consists of a symmetric construction that is prone to jamming and utilizes the advantageous technical effect of the gap in both directions.
Many known flap systems have relatively complex kinematic systems and consist of a large number of components (U.S. Pat. No. 2,276,522, U.S. Pat. No. 2,836,380, U.S. Pat. No. 2,920,844), wherein cam mechanisms that are prone to jamming are also used (U.S. Pat. No. 2,836,380, DE1943680, DE19803421 A1). In addition, spring elements (energy storage elements) are used that, in turn, generate higher driving loads (U.S. Pat. No. 2,169,416, U.S. Pat. No. 6,601,801). Flexible structures for Larger covered surfaces can only fulfill the strict aerodynamic tolerances conditionally (U.S. Pat. No. 4,395,008, U.S. Pat. No. 4,471,927).
Normal high-lift systems are designed for positive flap value positions only, wherein most systems are equipped with brake flaps on their upper side. The brake flaps are usually controlled by a separate drive (U.S. Pat. No. 4,120,470). Most concepts that are also suitable for negative flap value positions usually require an additional upper sealing flap on their upper side (flexible: U.S. Pat. No. 4,395,008, U.S. Pat. No. 4,471,927) or an upper ventilation flap (rigid: DE1943680) or spring-type seal (U.S. Pat. No. 6,601,801) in order to prevent a geometric collision with the upper wing contour. Until now, there exist no systems that simultaneously utilize the upper sealing flap as a brake flap in order to significantly reduce the number of control surfaces.
An adaptive wing typically requires additional complex systems that frequently collide with the existing primary and secondary control surfaces. Furthermore, additional drives, a large number of components, flexible structures and additional control circuits with the corresponding sensors are required. Two known systems are mentioned as examples of systems for adjusting the entire wing profile or profile pressure curve, respectively (DE19732953C1, DE 60002851T2).
It is an object of the present invention to develop a trailing edge control surface, in which primary as well as secondary control surfaces are realized on the wing with a lower mechanical expenditure and with less weight.
This object is achieved with an advanced trailing edge control surface with the features of claim 1. Advantageous embodiments and additional developments of the inventive trailing edge control surface are disclosed in the dependent claims.
The invention creates an advanced trailing edge control surface on the wing of an aircraft that comprises a wing, a flap that is arranged on the trailing edge of the wing, extends in the wingspan direction and can be adjusted to different flap value positions, a pivoted sealing flap that is arranged on the upper side between the wing and the flap and a pivoted ventilation flap that is arranged on the underside between the wing and the flap. According to the invention, the flap can be adjusted downward through positive flap value positions and upward through negative flap value positions, wherein the wing profile is closed on the upper side by the sealing flap and on the underside by the ventilation flap when the flap is used as a control flap and adjusted between negative and low positive flap value positions, and wherein the ventilation flap releases an air flow from the underside of the wing to the upper side of the flap and the sealing flap is retracted in order to form a predetermined gap and release an outflow of air from the upper side of the flap when the flap is used for increasing the lift and adjusted between low positive and high positive flap value positions.
According to a preferred embodiment of the inventive advanced trailing edge control surface, it is proposed that the trailing end of the sealing flap can be pivoted upward in order to utilize the sealing flap as a brake flap.
According to another preferred embodiment of the inventive advanced trailing edge control surface, it is proposed that the sealing flap is positively driven by the flap.
According to a preferred embodiment of the invention, a flap guide mechanism Is provided that contains a hinge arranged between the wing and the flap.
The pivotal point of the hinge preferably is positioned such that the flap does not diverge from the wing profile contour in negative flap value positions of the flap and a significant surface increase and curvature increase is achieved in positive flap value positions of the flap.
According to one preferred embodiment of the invention, it is proposed that the drive for the flap guide mechanism consists of a linear push-element or prismatic joint, respectively that is coupled to the wing and to the flap.
The prismatic joint preferably contains an actuator.
The actuator may be operated hydraulically (hydraulic actuator) or mechanically (spindle drive).
According to a preferred embodiment of the invention, it is proposed that the ventilation flap is positively driven by or mechanically gear-coupled with the flap.
According to a preferred embodiment of the invention, a ventilation flap mechanism is provided, in which the ventilation flap is connected to the wing by a lever mechanism that is supported on stationary bearings and contains two levers.
According to a preferred embodiment of the invention, a sealing flap mechanism is provided, in which the sealing flap is positively driven by the flap.
In the sealing flap mechanism, the sealing flap preferably is positively driven by the flap by a lever mechanism that is coupled to the flap at a second bearing near the stationary bearing and to the sealing flap by a third bearing near a fourth bearing.
The lever mechanism that connects the sealing flap to the flap and contains the coupling rod preferably forms a four-bar mechanism.
According to a preferred embodiment of the invention, it is proposed that the fourth bearing participates in a movement of the sealing flap in the sense of a brake flap function.
According to another preferred embodiment of the invention, another bearing is provided on the upper sealing flap and coupled to an actuator in order to actuate the sealing flap in the sense of a brake flap function.
The additional bearing is preferably arranged on a common pivoting axis with the fourth bearing.
The sealing flap mechanism is realized, in particular, such that a collision between the flap and the sealing flap is prevented between low positive flap angles and all negative flap angles of the flap and the sealing flap is sealed relative to the flap in the entire aforementioned range.
According to a preferred embodiment of the invention, it is proposed that the upper sealing flap is lowered in order to produce a convergent aerodynamic gap by being turned about the fourth bearing at higher positive flap value positions of the flap, in which the flap acts as a lift-increasing component.
A functional dependence between the absolute brake flap value position of the upper sealing flap (referred to the stationary wing) and the flap value position angle of the flap is preferably realized by a corresponding control in the flight control computer.
According to a preferred embodiment of the invention, it is proposed that the actuator device provided for the brake flap function moves the element along a circular path about a bearing by the additional bearing such that the double hinge formed by the fourth hinge and the additional hinge also moves along this circular path.
The brake flap mechanism preferably is largely decoupled from the upper sealing mechanism.
The brake flap mechanism may also be realized separately rather than being integrated into the kinematic system.
According to a preferred embodiment of the invention, it is proposed that all bearings consist of simple hinges.
According to another preferred embodiment of the invention, it is proposed that the construction essentially consists of rods and frameworks only.
According to a preferred embodiment of the invention, three-dimensional kinematics are provided for a cylindrical movement of the flap.
According to another preferred embodiment of the invention, three-dimensional kinematics are provided for a conical movement of the flap.
The advanced trailing edge control surface may serve as primary control surface.
The advanced trailing edge control surface may serve as secondary control surface.
The advanced trailing edge control surface may serve as adaptive wing component.
The inventive advanced trailing edge control surface is advantageously intended for use on the trailing wing edge of modern commercial aircraft and transport aircraft with a high take-off weight.
The inventive advanced trailing edge control surface is advantageously characterized by a low weight, by a high reliability, by a small number off components and by a structurally simple construction. The complex requirements with respect to an advanced trailing edge control surface concept were realized in the best fashion possible. in addition, the complete support structures and the kinematic system of a conventional high-lift system are eliminated. The aerodynamic fairing is significantly smaller in the advanced trailing edge control surface such that an economical advantage (reduced drag, lower fuel costs) will be achieved for the entire flight.
An embodiment of the inventive advanced trailing edge control surface is described in greater detail below with reference to the figures.
The figures show:
a) to e), respective schematic representations of the inventive trailing edge control surface with different adjustments of the flap, and
a) to c), respective schematic representations of the inventive trailing edge control surface wrath different adjustments of the upper sealing flap in its function as a brake flap.
The advanced trailing edge control surface on the wing of an aircraft is a schematically illustrated in its entirety in
a) to e), which are discussed in greater detail further below, show that the flap 4 (the reference symbols were omitted in
Since the mechanism of the advanced trailing edge control surface is somewhat unclear in the illustration of the entire advanced trailing edge control surface, the complete mechanism is divided into its four sub-mechanisms in
These four mechanisms are illustrated in their entirety in
The flap guide mechanism is illustrated separately in
The drive is realized by a linear prismatic joint 23 that is rotatably supported on the ends of the respective actuator element with the wing 1 and the flap 4. The actuator consists of the components 2 and 3 and may either be operated hydraulically (hydraulic actuator) or mechanically (spindle drive).
The principle of the ventilation flap mechanism is schematically illustrated in
The ventilation flap 5 is positively driven or mechanically gear-coupled with the flap 4, i.e., a defined functional dependence exists between these two elements. The mechanical coupling is realized by a simple rod 6. All bearings consist of simple hinges in the two-dimensional drawing, wherein these bearings may analogously consist of different joints in a three-dimensional embodiment, e.g., ball-and-socket joints with three degrees of rotational freedom. The mechanical principle remains the same in the three-dimensional space such that a two-dimensional illustration suffices. The joints 15, 14, 56 and 46 therefore consist of simple hinges in the two-dimensional drawing. This means that the entire geared coupling is realized with the simplest conceivable mechanism (four-bar mechanism).
At higher positive flap angles of the flap 4, see
At lower positive and all negative flap angles of the flap 4, the ventilation flap 5 remains almost in its nominal position. In this case, the nominal position is characterized by the profile contour while cruising. This means that a “quasi” state of rest is achieved in the range between low positive and high negative flap value positions of the flap 4 due two an advantageous technical design of the transmitting gear (the aforementioned four-bar mechanism). In addition, a complete seal of the ventilation flap relative to the flap 4 is ensured in the range between low positive and high negative flap value positions of the flap 4 such that the profile contour always remains favorable with respect to the air flow (low aerodynamic drag) and detrimental sources of noise in the form of edges, abrupt profile contour changes or down-draught areas are prevented.
The principle of the sealing flap mechanism is schematically illustrated in
The functions of the upper sealing flap 7 are described in detail below. Due to the requirement of allowing negative flap value positions of the flap 4, it becomes necessary to raise the upper wing contour or the brake flaps that are normally situated at this position on commercial aircraft so as to prevent a collision between the sealing flap 7 (the sealing flap 7 simultaneously forms the brake flap, see explanations below) and the flap 4.
Between lower positive flap angles, see
At higher positive flap value positions of the flap 4, see
Since the simplest mechanical solution is once again favored for such a geared coupling, all aforementioned requirements are realized with an advantageous design of the aforementioned four-bar mechanism (bearings 79, 78, 48, 14). A mechanical coupling rod 8 connects the sealing flap 7 and the flap 4.
The operation of the brake flap mechanism is almost completely decoupled from the flap mechanism, wherein a functional dependence only exists between the absolute brake flap value position of the upper sealing flap 7 (referred to the stationary wing 1) and the flap value position angle of the flap 4, and wherein this functional dependence is taken into account by a corresponding control in the flight control computer. This control does not affect the sealing flap mechanism (except in case of a defect) because the aerodynamic gap dimension is eliminated in the brake flap mode such that a corresponding loss of lift occurs and the aerodynamic drag is increased.
The normal brake flap functions therefore can still be realized with an additional drive (element 10 and element 11) without impairing the function of the above-mentioned mechanism of the lower panel (ventilation flap) 5 and the upper panel (sealing flap) 7. The typical brake flap acts, among other things, as an air brake, as a lift eliminator, as a roll control and as a wing alleviation.
If so required, the brake flap mechanism could also be realized separately rather than being integrated into the kinematic system, wherein this would be conceivable in the form of an aileron in the outer wing region.
At negative flap value positions and low positive flap value positions of the flap 4, the wing profile contour is completely sealed (by the lower ventilation flap 5 and the upper sealing flap 7 and favorable with respect to the air flow such that an advantageous coefficient of drag is achieved and no vortices are generated that could also contribute to the noise emission (see
The aerodynamic flap gap is exactly maintained by a mechanical geared coupling with the flap 4 such that no complex control circuit is required for maintaining the flap gap (aerodynamic air gap tolerances). These functions are realized solely with the actuator for the flap 4 (actuator body 2 and actuator rod 3). At higher positive flap angles of the flap 4, the lower ventilation flap 5 pivots into the wing profile contour and the advantageous air flow around the flap 4 is achieved. Beginning at higher flap angles of the flap 4, the upper sealing flap 7 no longer acts as a seal, but rather needs to exactly maintain the aerodynamic flow convergence and the aerodynamic gap dimension, see
Aerodynamic fairings (fairings) are provided in the regions in which the lower ventilation flap 5 is penetrated by the coupling rods 6 and 8 and in which support structures extend toward the wing 1, respectively.
The inventive trailing edge control surface makes it possible to realize a primary as well as a secondary flight control. In other words, high adjusting speeds for primary control surfaces can be achieved.
The inventive trailing edge control surface may act as an adaptive wing, wherein the most economically favorable operating point can be adjusted for the respective altitude (density, temperature, etc.), load status and cruising speed in the form of low positive or negative stationary flap value positions. The wing profile contour remains closed for low positive flap value positions and all negative flap value positions (except in the brake flap mode) and the profile contour remains aerodynamically favorable. In conventional secondary high-lift systems, this would usually not be possible because negative flap value positions could not be realized.
The brake flap mode of the upper sealing flap 7 that acts as brake flap in this case is illustrated in different configurations in
It should be additionally noted that “comprising” does not exclude any other elements or steps and “a” or “an” does not exclude a plurality. It should furthermore be noted that characteristics or steps that were described with reference to one of the above embodiments can also be used in combination with other characteristics or steps of other above-described embodiments. The reference symbols in the claims should not be interpreted in a restrictive sense.
1 Wing
2 Actuator body
3 Actuator rod
4 Flap
5 Ventilation flap
6 Rod
7 Sealing flap
8 Connecting rod
9 Connecting rod
10 Actuator rod
11 Actuator body
12 Stationary bearing
14 Stationary bearing
15 Stationary bearing
19 Bearing
23 Connecting rod
34 Bearing
46 Hinge
48 Second bearing
56 Hinge
78 Third bearing
79 Forth bearing
111 Stationary bearing, hinge
910 Bearing
1011 Connecting rod
Number | Date | Country | Kind |
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102005045759.2 | Sep 2005 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP2006/009067 | 9/18/2006 | WO | 00 | 9/3/2009 |