NL2013594B1

NL2013594B1 - Air guiding structure.

Info

Publication number: NL2013594B1
Application number: NL2013594A
Authority: NL
Inventors: Philip Maria Werter Noud; De Breuker Roeland; Sodja Jurij; Spirlet Gregory; Senkal Birol
Original assignee: Univ Delft Tech
Priority date: 2014-10-08
Filing date: 2014-10-08
Publication date: 2016-10-04

Abstract

Air guiding structure selected from the group comprising an airplanes wing, a car spoiler and a wind turbine blade, which structure comprises a stationary part and at least one movable part connected to the stationary part and which movable part forms an edge of the structure, wherein the structure has a movable leading part which forms a morphing leading edge, and a movable trailing part which forms a morphing trailing edge, wherein said leading part and said trailing part are placed on opposite sides of the stationary part.

Description

Air guiding structure

The invention relates to an air guiding structure, which structure comprises a stationary part and at least one movable part connected to the stationary part, which movable part forms an edge of the structure, and wherein the structure has a movable leading part which forms a morphing leading edge, and a movable trailing part which forms a morphing trailing edge, wherein said leading part and said trailing part are placed on opposite sides of the stationary part.

Such an air guiding structure may be embodied as an airplanes wing, a car spoiler or a wind turbine blade.

The PhD Thesis of October 2012 by Natalia Di Matteo, entitled "Optimal Design and Numerical Analysis of a Morphing Flap Structure", Department of Aerospace Engineering;

Cranfield University provides an up-to-date overview of the existing prior art in the field of airplanes wings. The thesis acknowledges that a main objective of aircraft design is the development of aircraft technologies able to satisfy the rising demand for lower travel costs, better service quality and high safety standard, while achieving a significant reduction in the perceived noise generated and a drastic cut of the fuel consumption and polluting emissions. The thesis identifies that the use of morphing could allow the airplanes wing to adapt its shape smoothly under different loading conditions, to achieve near-optimal lift and drag profiles throughout all the different phases of a flight. The main advantages of this would be a reduced fuel consumption and a higher aerodynamic efficiency. Additional benefits coming from morphing are an improved control of the aircraft during flight and a better load distribution over the wing. The thesis also discloses that commercial airliners nowadays are already equipped with high lift devices for both the leading and the trailing edge. Correspondingly the preamble of the main claim reflects this known prior art.

One of the concepts introduced in 1962 as acknowledged by the thesis is the so-called Boeing droop nose (thesis page 27). This design has several disadvantages, notably the actuation mechanism used in this concept results in a very heavy and complex structure. Further the structure limits the degrees of freedom of the air guiding structure in that it is only possible to change the camber of the air guiding structure downwards. WO99/15403 discloses wings of an airplane that are provided with leading and trailing edges that both are equipped with airfoils that are movable between raised and lowered positions. The document discloses that actuators are applied that move upper and lower control rods of the associated airfoil. The upper and lower control rods are either moved in unison to move the airfoil between a retracted and an extended position with reference to the wing, or in a way that a relative movement occurs between the upper control rods and the lower control rods to move the airfoil inclined upwards or inclined downwards with reference to the wing. US 4,729,528 discloses an aircraft having wings that are provided with auxiliary flaps in the form of streamlined plates or airfoils shaped to complement the configuration of the wing along the wing section to which the airfoils are attached. The auxiliary flaps are movable from wing aligned or level position, downwardly or upwardly, individually or together.

In both said publications a conventional rigid flap is applied that is hinged in order to achieve upward or downward motion, as opposed to the features of the invention as will be explained hereinafter.

It is an object of the invention to further develop the prior art designs and to introduce more flexibility in the camber that can be applied to the air guiding structure.

It is another object of the invention to simplify the existing designs and to reduce weight of the air guiding structure .

Generally speaking it is an object of the invention to provide an air guiding structure capable of covering a larger range of flight conditions when it is applied to an airplanes wing.

It is another object of the invention to propose a design that enables plug-and-play of the air guiding structure and modularity of its parts to enable easy maintenance and re- placement.

It is still another objective of the invention to provide an air guiding structure that allows for a combination of twist and camber morphing.

These and other objectives and advantages of the invention are promoted by an air guiding structure having the features of one or more of the appended claims.

Although in the following the invention will be primarily be explained and elucidated with reference to the application to an airplanes wing, it is expressly noted that the invention is not restricted to this application, and that the invention can be likewise used in design of blades for windturbines and in spoilers for cars as well as in other applications in which an optimal air guiding structure is required.

The air guiding structure of the invention is arranged such that the movable leading part, the stationary part and the movable trailing part possess a neutral position, and that both the movable leading part and the movable trailing part are positionable in a first deflected position from said neutral position and in a second deflected position from said neutral position, wherein the first deflected position and the second deflected position are on opposite sides relative to a midplane of the stationary part and relative to the neutral or clean position of the air guiding structure, wherein the structure is further arranged to provide either a simultaneous upward deflection and downward deflection of the same movable part causing twisting to said part, or a simultaneous upward deflection and downward deflection combined with an overall deflection in upward or downward direction of the same movable part causing twisting and camber to said part.

The first deflected position and the second deflected position come near to represent each other's mirror image on opposite sides with reference to the neutral or clean position. This ensures a relatively high degree of flexibility of the air guiding structure and provides optimal manoeuvrability of an airplane provided with such an air guiding structure of the invention.

It is preferred that within each movable leading part and each movable trailing part an actuator or actuators are mounted that act on the stationary part so as to adjust (at least in part) the position of the movable leading part and the movable trailing part with reference to the stationary part. This placement of the actuators within the movable parts enables a relatively simple construction of the actuators to be used, and is also beneficial in arranging the plug-and-play character and easy maintenance and replacement of any such movable part that is to be mounted on a stationary part.

Desirably the movable leading part and the movable trailing part share at a first side of the structure a smooth external surface with the stationary part. This allows for an increased aerodynamic efficiency, which is in particular promoted when the said surface is seamless.

At a second side of the structure facing away from the first side of the structure, the stationary part is slidably connected with the movable leading part and with the movable trailing part. This makes it is possible to introduce not only camber but also twist in the air guiding structure by allowing at said second side of the structure free movement in spanwise direction of the skin of the concerning movable part with reference to the stationary part. It further provides the advantage of favourably influencing the load distribution over the wing surface, which results in lower structural weight and improved aerodynamic performance.

Desirably the slidable connection is provided at the second side of the structure by arranging that the stationary part is provided with slits, wherein each slit has an opening facing the movable leading part respectively the movable trailing part, and which slits are equipped to receive therein surface skins of said movable leading part respectively said movable trailing part. This avoids the occurrence of gaps between the stationary part on the one hand and the leading part and trailing part respectively on the other hand when these are moved out of the neutral or clean position of the air guiding structure.

The invention will hereinafter be further elucidated with reference to the drawing of an exemplary embodiment of an apparatus according to the invention that is not limiting as to the appended claims.

In the drawing: -figure 1 shows schematically a top view of an airplane provided with an air guiding structure according to the prior art; -figure 2 shows an exemplary embodiment of a leading edge- or trailing edge movable part connected to a stationary part of an air guiding structure according to the invention; -figure 3 shows an isometric and for illustrative purposes transparent view at a leading edge or trailing edge movable part connectable to a stationary part of an air guiding structure according to the invention; -figure 4 shows a detailed view at a cooperating slit of a stationary part and skin of a movable part received therein; -figure 5 provides a side view of the movable part of figure 3; and -figure 6 provides a side view of the movable part of figure 3 from the side opposite to what is shown in figure 5.

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

Making reference first to figure 1 a fuselage 4 of an airplane is shown that is provided with an air guiding structure embodied as a wing comprising a stationary part 2 {which is conventionally referred to as the wing box) and one or more movable parts 1, 3 connected to said stationary part 2. The movable parts 1, 3 consist of movable leading parts 1 or slats, and movable trailing parts 3 or flaps. The movable parts 1, 3 are provided on opposite sides of the stationary part 2 and thus form the trailing and leading edges of the air guidance structure.

As is conventionally the case the movable leading parts 1, the stationary part 2 and the movable trailing parts 3 possess a neutral or clean position corresponding to aerodynamic properties most suited for e.g. cruise flight conditions. Both the movable leading parts 1 and the movable trailing parts 3 are positionable in a first deflected position from said neutral position and in a second deflected position from said neutral position, wherein the first deflected posi- tion and the second deflected position are on opposite sides relative to a midplane of the stationary part 2 and relative to the neutral or clean position of the air guiding structure.

In figure 2 a possible deflection of the movable part 1, 3 is shown in which the continuous lines represents an initial configuration of for instance the movable leading edge. This might however likewise represent the deflection of the movable trailing edge. In a dashed line an entirely upwards deflection of the movable part is shown. It is however also possible that the deflection and the corresponding camber is of opposite sign, meaning that the movable part will be entirely downwardly deflected.

Figure 2 further shows schematically that within the movable part (being either a movable leading part 1 or a movable trailing part 3) an actuator 5 (or actuators) are mounted that act on the stationary part 2 so as to adjust at least partially the position of the movable part 1, 3 with reference to the stationary part 2.

In figure 3 the feature of the invention is shown in which a simultaneous upward deflection and downward deflection of the same movable part is realized which provides twisting of this part. The manner in which this is enabled will be discussed hereinafter.

Figure 3 shows that the movable part 1, 3 (again being either the leading part 1 or the movable trailing part 3) share at a first side 6 of the structure a smooth surface with the stationary part 2. This is preferably embodied by arranging that the said surface 6 is seamless and this beneficially arranges for the possibility that optimal aerodynamic conditions exist when applied to an airplane wing at the upper side of its air guiding structure.

At a second side 7 of the structure facing away from the first side 6 of said structure the stationary part 2 is slidably connected with the movable part 1, 3. A detailed view is provided by figure 4 clearly showing that at this second side 7 of the structure the stationary part 2 is provided with a slit 8, which slit 8 has an opening facing the movable part 1, 3 and which slit 8 is equipped to receive therein a surface skin 9 of said movable part 1, 3. Due to this construction it is possible to have the movable parts 1, 3 execute both a movement in the chordwise direction as in the spanwise direction of the air guiding structure. This twisting motion is shown in figure 3.

Figure 3 further shows that two actuators 5 are mounted on respective sides of the movable part 1, 3 wherein each actuator 5 acts on the stationary part 2 for adjusting the position of a local part of the movable part 1, 3 with reference to the stationary part 2. It is remarked that the number of actuators may vary. When the two actuators 5 actuate in different directions the twisted motion of the movable part 1, 3 occurs as shown in figure 3, wherein on one side indicated with A (which side is more clearly shown in figure 5) the movable part 1, 3 is deflected upwards (as indicated with the dashed line), and wherein on the other side B (which side is more clearly shown in figure 6) the movable part 1, 3 is simultaneously deflected downwards (as indicated with the same dashed line).

As mentioned figure 5 provides a view at the movable part 1, 3 as seen from side A of figure 3. The dashed lines 10 represents the frontal part A as shown in figure 3, whereas the dashed lines 11 represent the rear part B as shown in figure 3. Likewise figure 6 provides a view at the movable part 1, 3 as seen from side B of figure 3. The dashed lines 11 represent the then frontal part B as shown in figure 3, whereas the dashed lines 10 represent the then rear part A as shown in figure 3.

Although the invention has been discussed in the foregoing with reference to an exemplary embodiment of the air guiding structure 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.

Claims

An air guidance structure selected from the group comprising an airplane wing, a car spoiler and a wind turbine blade, which structure comprises a stationary part (2) and at least one movable part (1, 3) connected to the stationary part (2) and said movable member (1, 3) forming an edge of said structure, said structure having a movable leading member (1) forming a morphing leading edge, and having a movable trailing member (3) forming a morphing trailing edge, said leading part (1) and said trailing part (3) are placed on opposite sides of the stationary part (2), the movable leading part (1), the stationary part (2) and the movable trailing part (3) have a neutral or clean position, and that both the movable leading part (1) and the movable trailing part (3) are positionable in a first deflected position relative to said neutral position and in a second deflected position with respect to said neutral position, wherein the first deflected position and the second deflected position lie on opposite sides with respect to a central plane of the stationary part (2) and with respect to the neutral or clean position, characterized in that that the structure is arranged to provide either a simultaneous upward and downward deflection of the same movable member for twisting said member, or a simultaneous upward and downward deflection combined with an overall upward or downward deflection of the same movable member which twist and downward camber provided to said part.

Air guiding structure according to claim 1, characterized in that within both the movable leading part (1) and the movable trailing part (3) an actuator or actuators (5) are mounted which act on the stationary part (2) in order to at least partly adjust the position of the movable leading part (1) and the movable trailing part (3) relative to the stationary part (2).

Air guiding structure according to one of claims 1-2, characterized in that the movable leading part (1) and the movable trailing part (3) on a first side (6) of the structure share a smooth surface with the stationary part ( 2).

Air guiding structure according to claim 3, characterized in that said surface is seamless.

Air guiding structure according to claim 3 or 4, characterized in that on a second side (7) of the structure remote from the first side (6) of the structure the stationary part (2) is slidably connected to the movable front part (1) and with the movable trailing part (3).

6.

Air guiding structure according to claim 5, characterized in that on the second side (7) of the structure the stationary part (2) is provided with slots (8), each slot having an opening facing the movable leading part (1) ) or the movable trailing part (3), and which slots (8) are adapted to receive therein surface skins (9) of said movable leading part (1) and said movable trailing part (3).