AN AIRCRAFT WING PROVIDED WITH A TRAILING EDGE REGION

Abstract

An aircraft wing (1) provided with a trailing edge region (2) which is provided with a noise attenuation structure, which at least comprises in combination, looking in an upwards direction: a first micro perforated plate (2.1) with micro perforations, a structure (2.2) with open channels, a second micro perforated plate (2.3) with micro perforations, and a third micro perforated plate (2.4) with micro perforations, wherein the open channels of the structure (2.2) connect micro perforations of the first micro perforated plate (2.1) with micro perforations of the second micro perforated plate (2.3), and that at least one of the second micro perforated plate (2.3) and the third micro perforated plate (2.4) is slidable with respect to the other for aligning and/or misaligning the micro perforations of the second micro perforated plate (2.3) and the third micro perforated plate (2.4) with respect to each other, wherein the trailing edge region (2) is delimited by a trailing edge, wherein a density of the micro perforations in the respective micro perforated plates (2.1, 2.3, 2.4) increases towards the trailing edge.

Claims

1. An aircraft wing provided with a trailing edge region wherein the trailing edge region is provided with a noise attenuation structure which at least comprises in combination, looking in an upwards direction: a first micro perforated plate with micro perforations, a structure with open channels, a second micro perforated plate with micro perforations, and a third micro perforated plate with micro perforations, wherein the open channels of the structure connect micro perforations of the first micro perforated plate with micro perforations of the second micro perforated plate, and that wherein at least one of the second micro perforated plate and the third micro perforated plate is slidable with respect to the other for aligning and/or misaligning the micro perforations of the second micro perforated plate and the third micro perforated plate with respect to each other, wherein the trailing edge region is delimited by a trailing edge, and wherein a density of the micro perforations in the respective micro perforated plates increases towards the trailing edge.

2. The aircraft wing according to claim 1, wherein a relative position of at least one of the second micro perforated plate and the third micro perforated plate is controllable with an actuator that is arranged to slide the at least one of the second micro perforated plate and the third micro perforated plate with respect to each other,

3. The aircraft wing according to claim 1, wherein the micro perforations of the second micro perforated plate and the micro perforations of the third micro perforated plate are attuned to each other so as to arrange that the second micro perforated plate and the third micro perforated plate are able to occupy a first position wherein the micro perforations of the second micro perforated plate and the micro perforations of the third micro perforated plate are misaligned, and a second position wherein the micro perforations of the second micro perforated plate and the micro perforations of the third micro perforated plate are aligned, as well as a position between the first position and the second position.

4. The aircraft wing according to claim 1, wherein on top of the third micro perforated plate is a smooth acoustically permeable surface layer.

Description

[0017] In the drawing:

[0018] FIG. 1 shows an aircraft with an aircraft wing of the invention in a top view and a side view;

[0019] FIG. 2 shows an exploded view of a noise attenuation structure as applied in the trailing edge region of the aircraft wing of the invention; and

[0020] FIG. 3 shows different modes of application of the noise attenuation structure of FIG. 2.

[0021] Whenever in the figures the same reference numerals are applied, these numerals refer to the same parts.

[0022] FIG. 1 shows an aircraft with an aircraft wing 1 provided with a trailing edge region 2. Usually the aircraft wing 1 supports an engine 3.

[0023] According to the invention the trailing edge region 2 is provided with a noise attenuation structure which is shown in an exploded view in FIG. 2. The noise attenuation structure as shown in FIG. 2 comprises in combination, looking in an upwards direction: a first micro perforated plate 2.1 with micro perforations, a structure 2.2 with open channels, a second micro perforated plate 2.3 with micro perforations, and a third micro perforated plate 2.4 with micro perforations, wherein the open channels of the structure 2.2 connect micro perforations of the first micro perforated plate 2.1 with micro perforations of the second micro perforated plate 2.3. Further at least one of the second micro perforated plate 2.3 and the third micro perforated plate 2.4 is slidable with respect to the other as symbolized by the arrows A, for aligning and/or misaligning the micro perforations of the second micro perforated plate 2.3 and the third micro perforated plate 2.4 with respect to each other.

[0024] Preferably the open structure 2.2 is a honeycomb structure, but this is not essential.

[0025] Accordingly a relative position of at least one of the second micro perforated plate 2.3 and the third micro perforated plate 2.4 is controllable with an actuator (not shownbut clear to the skilled person) that is arranged to slide the at least one of the second micro perforated plate 2.3 and the third micro perforated plate 2.4 with respect to each other.

[0026] It is further observed that preferably the micro perforations of the second micro perforated plate 2.3 and the micro perforations of the third micro perforated plate 2.4 are attuned to each other so as to arrange that the second micro perforated plate 2.3 and the third micro perforated plate 2.4 are able to occupy a first position wherein the micro perforations of the second micro perforated plate 2.3 and the micro perforations of the third micro perforated plate 2.4 are misaligned, and a second position wherein the micro perforations of the second micro perforated plate 2.3 and the micro perforations of the third micro perforated plate 2.4 are aligned, as well as any position between the first position and the second position.

[0027] Accordingly FIG. 3 shows the following options: [0028] Mode 1. The micro perforations of the second and third micro perforated plates 2.3, 2.4 are misaligned, providing no permeability through any of the honeycomb channels. The noise attenuation structure of the aircraft wing of the invention then operates as an acoustic liner. This mode 1 can be activated when the flaps are fully retracted during the cruise phase of the flight. [0029] Mode 2. Some of the micro perforations of the second and third micro perforated plates 2.3, 2.4 are aligned, providing permeability through some of the honeycomb channels. This provides a hybrid noise attenuation structure of the aircraft wing of the invention, between the acoustic liner option mode 1, and the following mode option 3 representing a fully permeable structure. This mode 2 can be activated when the flaps are partially deployed during takeoff. [0030] Mode 3. The micro perforations of the second and third micro perforated plates 2.3, 2.4 are all aligned, providing permeability through all of the honeycomb channels. The noise attenuation structure is fully permeable, and this mode 3 can be activated when the flaps are fully deployed during the approach phase.

[0031] It is further remarked that the trailing edge region 2 is delimited by a trailing edge, wherein a density of the micro perforations in the respective micro perforated plates 2.1, 2.3, 2.4 increases towards the trailing edge.

[0032] Finally it is remarked with reference to FIG. 2 that on top of the third micro perforated plate 2.4 preferably a smooth acoustically permeable surface layer 2.5 is provided.

[0033] Although the invention has been discussed in the foregoing with reference to an exemplary embodiment of an aircraft wing of the invention, the invention is not restricted to this particular embodiment which can be varied in many ways without departing from the invention. The discussed exemplary embodiment shall therefore not be used to construe the appended claims strictly in accordance therewith. On the contrary the embodiment is merely intended to explain the wording of the appended claims without intent to limit the claims to this exemplary embodiment. The scope of protection of the invention shall therefore be construed in accordance with the appended claims only, wherein a possible ambiguity in the wording of the claims shall be resolved using this exemplary embodiment.