JPH07132891A - Laminar flow keeping type high-lift device - Google Patents

Abstract

PURPOSE:To facilitate a change between a cruising condition and a high-lift condition by providing either of a frontal line slat or a leading-edge Krueger flap formed on the front of a wing leading-edge part made into an adhesive streamline laminar flow type profile when developing operation is made to a high-lift flight condition from a cruising flight condition. CONSTITUTION:A leading-edge profile outer plate 1 and a Krueger flap 6 form the front part lower surface of a main wing in a cruising condition, the leading- edge profile outer plate 1 forms a leading-edge having a large radius, that is, an adhesive streamline laminar flow type profile, and the Krueger flap 6 is moved to the front to form the Krueger flap in a high-lift condition. The development into a high-lift condition actually increases the leading-edge radius of the main-wing leading-edge part 5, consequently the path of a flow along a leading edge is lengthened to increase the movement quantity of the flow per unit time, that is, a flow velocity, to increase a velocity gradient. As a result, a boundary layer is thinned to become an adhesive streamline laminar flow to maintain a laminar flow over a broad region from the leading-edge lower part to the upper surface of the wing, generating a very large lift compared with a conventional turbulent type.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high lift device such as an aircraft main wing or flap, and more particularly to a device for changing the leading edge contour shape of those wings.

[0002]

2. Description of the Related Art Conventional high lift devices for aircraft, which are mainly used at the time of takeoff and landing, are roughly classified into a front edge high lift device and a trailing edge high lift device.

First, the conventional leading edge high lift device is roughly classified into the following four types as shown in FIG.

(A). Slats (b). Kruga flap (c). Front edge bending (d). Kruga flap (b) and front edge bend (c)
The slat of combination (a) is a separate component from the wing body as a slat 02 having a small wing shape at the leading edge of the main wing 01. In the cruising state, the slat 02 is in close contact with the wing body. In a state where high lift is required, it is projected forward and downward so as to form a gap (slot) with the wing body. When there is no slat, the lift force does not increase because the flow from the lower surface to the upper surface of the main wing 01 does not go around the leading edge and separates at a large angle of attack. The lift force increases because the flow that wraps around to the upper surface passes through the gap between the slat 02 and the wing body and does not cause separation.

The Kruger flap (b) has a main wing 01
This is a device in which a part of the lower surface of the leading edge of the No. 4 is projected as a Kruga flap 03 to the lower front. The warp of the main wing 01 is increased, the chord length is increased, and the leading edge radius is increased to increase the lift force. Is to increase.

The leading edge bending of (c) increases the warp of the main wing 01 by locally bending the leading edge portion of the main wing 01 downward as the leading edge bending portion 04, and
The lift angle is increased by reducing the angle of the leading edge with respect to the air flow and suppressing the separation of the air flow. Further, the shape contour of the leading edge bent portion 04 bent downward holds the contour of the leading edge portion of the original blade to the maximum.

(D) is a combination of the above techniques (b) and (c) so that both effects can be obtained.

FIG. 4 is a detailed view of a conventional Kruga flap type front edge high lift device, in which (a) is an expanded state,
(B) is a diagram of the stored cruise state. Wing leading edge 05
Kruga flap 0 with a relatively long chord length from the underside of the
6 is generally deployed forward by the rotation of the torque tube 08 via the link mechanism 07.

Next, conventional trailing edge high lift devices are roughly classified into the following three types as shown in FIG.

(E) Simple flap (f) Split flap (g) Slotted flap In the simple flap of (e), the trailing edge portion of the blade 05 is a simple flap 06, and it is bent downward as shown in FIG. Thereby increasing the warp of the wing 05 and increasing the lift, in which case the front edge portion of the simple flap 06 is not exposed to the air flow.

In the split flap (f), the lower surface of the trailing edge of the blade 05 is split flap 07, as shown in FIG.
As shown in (i), the blade is opened downward to increase the negative pressure at the trailing edge of the blade to increase the lift. In this case as well, the shape of the leading edge of the split flap 07 itself does not change.

The slotted flap (g) has wings 05
On the other hand, the slotted flap 08 is bent downward as shown in Fig. (J), and at the same time, it is moved slightly backward to form a gap (slot) between itself and the blade main body, and a high pressure on the lower surface of the blade is passed through this gap. Is directed to the upper surface side of the blade and energy is applied to the boundary layer on the upper surface side to suppress separation of the air flow and increase lift. The slotted flap 08 is further divided, and double slotted flaps and triple slotted flaps with two slots and three slots are also used, but in both cases, the shape of the front edge of the slotted flap itself is It retains a contour similar to the leading edge of the wing.

In the above description, the "leading edge high lift device" and the "rear edge high lift device" refer to the main wing. Thus, for example, the "leading edge" of a flap refers to the leading edge of the flap in a trailing edge high lift device.

[0014]

The conventional leading edge high lift device and trailing edge high lift device described above have the following problems to be solved.

That is, in the prior art, when the slats and the Kruga flaps, which are the leading edge high lift devices, and the slotted flaps, which are the trailing edge high lift devices, are deployed, the portions left behind the gap (slot) are removed. The leading edge shape retains it to the maximum extent, with almost no protrusion from the contour of the original shape. Therefore, the remaining leading edge portion has a small leading edge radius, and the amount of acceleration from the flow attachment line to the upper surface side is small, so the flow attachment streamline is turbulent, and the blade upper surface side is a turbulent region. The maximum lift is limited due to the development of thick turbulent boundary layers. In addition, depending on the velocity gradient at the leading edge of the blade, the flow may cause a relaminarization phenomenon at the leading edge, but in this case as well, a thick turbulent boundary layer develops from the attachment line, and There was a problem that the re-lapping basin was also small and the maximum lift was limited.

In this case, the functions of the slats, the kruga flaps, and the slotted flaps, in addition to the above-mentioned original function of increasing the warp of the blade, create a clearance between the front edge of the remaining blade and this clearance. The accelerated slot flow through slows the separation on the wing surface left behind, or on the flap surface, increasing the maximum lift. This allows slats,
In addition to the increase in the maximum lift coefficient due to the original function of the Kruga flap and the slotted flap, the maximum lift coefficient of the wing body also increases, but the maximum lift is also limited because the attached streamlines are turbulent. there were.

FIGS. 3A to 3D schematically show the conventional problems described above.

In order to solve the above problems, it is an object of the present invention to provide a laminar flow maintaining front edge high lift device capable of easily changing between a cruise state and a high lift state and obtaining a large lift force. To do.

[0019]

As a means for solving the above-mentioned problems, the present invention provides a high-lift device for deploying an aircraft to change the contour shape of a wing to a high-lift flight state when the aircraft requires a high-lift force. When the wing leading edge contour shape was changed from the cruise type contour to the adhering streamline laminar flow type contour during the deployment operation from the flight state to the high lift flight state It is an object of the present invention to provide a laminar flow maintaining type high lift device characterized in that it comprises either a leading edge slat or a leading edge Kruga flap to be formed.

In the above description, the "adherent streamlined laminar flow type contour" means a contour of a blade cross section (blade shape) that satisfies the following equations (1) and (2).

[0021]

[Equation 1]

[0022]

[Equation 2]

Where R θ: Reynolds number formed from the momentum thickness of the boundary layer along the attached streamline U: Local velocity of the boundary layer along the attached streamline θ: Momentum thickness of the boundary layer along the attached streamline ν: Aerodynamic viscosity Λ: Leading edge of blade or adhering streamline receding angle Note that hereinafter, unless otherwise specified, the "contour" means the contour of the blade cross section (wing type), and the "cruise type contour" means cruise flight. Say the contour of the wing cross section.

[0024]

Since the present invention is constructed as described above, it has the following actions.

That is, in order to change the wing leading edge contour shape from the cruise type contour to the adhering streamline laminar type contour when the laminar flow maintaining type high lift device of the aircraft is deployed and operated from the cruising flight state to the high lift flight state. In addition, the contour shape of the blade leading edge becomes the adhering streamline laminar flow type contour, and laminar flow is realized from the blade leading edge portion, and the lift is greatly increased compared to the conventional turbulent flow type.

Further, the laminar flow maintaining type high lift device is provided with either a leading edge slat or a leading edge Kruger flap which is deployed in front of the leading edge portion of the blade having the adhering streamline laminar flow type contour. , The laminar flow induced by the adhering streamline layer profile is
The slot flow generated by the leading edge slat or the leading edge Kruger flap maintains the high Reynolds number region, that is, the flying Reynolds number region, and further increases the lift force.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. Note that FIG. 3 is also used as a comparative diagram in common with the conventional example.

An embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a sectional view of the vicinity of the leading edge of the main wing corresponding to the so-called airfoil cross section of the laminar flow maintaining type high leading edge lift device according to this embodiment. , Also referred to as a deployed state), and (b) shows a cruise state in which the device is housed.

FIG. 2 shows the results of the wind tunnel test of this embodiment as a conventional example,
It is the figure shown in comparison with an example and a comparative example (a type equivalent to removing a Kruga flap from an example).

In FIG. 1, reference numeral 1 designates the leading edge contour shape of the wing leading edge portion 5 attached from the cruise type contour ((b) in the figure) when the apparatus of this embodiment is deployed from the cruising state to the high lift state. The leading edge contour outer plate 5 which is changed to a part of the streamlined laminar flow type contour ((a) in the figure) is the leading edge portion of the main wing. 6 is a part of the lower surface of the main wing following the leading edge contour skin 1 in the cruising state, and protrudes forward in the high lift state to form the attached streamline laminar flow formed by the leading edge contour skin 1 as the leading edge. It is a Kruga flap that is hung vertically in front of the mold contour.

That is, in the cruising state, as shown in FIG. 1 (b), the leading edge profile skin 1 and the Kruga flap 6 form the front lower surface of the main wing, and in the high lift state, the leading edge profile skin 1 has a radius. Forming a large leading edge, i.e. the adhering streamlined laminar profile, the Kruger flap 6 projects forward and forms the Kruger flap.

Reference numeral 7 denotes a link mechanism for expanding and accommodating the front edge contour outer plate 1 and the kruga flap 6 from a cruising state to a high lift state and from a high lift state to a cruising state, and 8 denotes a drive mechanism (not shown) for the link mechanism 7. The torque tube for turning operation by the source, 9 is a slot (gap) provided between the front edge contour outer plate 1 and the Kruga flap 6 for generating a slot flow in a high lift state.

In the high lift state shown in FIG. 1 (a),
The adhering streamlined laminar flow type contour formed by the leading edge contour skin 1 is formed so as to satisfy the expressions (3) and (4).

[0035]

[Equation 3]

[0036]

[Equation 4]

Where R θ: Reynolds number created from the momentum thickness of the boundary layer along the attached streamline U: Local velocity of the boundary layer along the attached streamline θ: Momentum thickness of the boundary layer along the attached streamline ν: Air dynamic viscosity Λ: Leading edge of blade or adhering streamline receding angle Next, the operation of the above-described embodiment will be described.

As described above, when the apparatus is deployed in the high lift state shown in FIG. 1A, the leading edge radius of the main wing leading edge portion 5 becomes substantially large, so that the flow path along the leading edge becomes long. Therefore, the amount of movement of the flow per unit time, that is, the flow velocity increases, and the velocity gradient increases. As a result, the boundary layer becomes thinner and becomes a sticky streamlined laminar flow, which maintains a laminar flow over a wide area from the lower part of the leading edge of the blade to the upper surface, generating an extremely large lift as compared with the conventional turbulent flow type. To do.

Further, since the Kruga flap 6 is vertically provided in the front and the slot 9 is formed, the slot flow flows from the slot 9 in a direction to promote the laminar flow toward the outer periphery of the front edge contour outer plate 1 upward. The boundary layer formed by the adhering flow is further thinned, and the laminar flow is maintained even in the high Reynolds number region to generate a larger lift than in the case of the conventional example.

Further, as shown in FIG. 2, also in the comparison of the wind tunnel test results, CL _max (maximum lift coefficient) of this embodiment is about 0.25 larger than that of the conventional turbulent flow type leading edge + Kruga flap example. It turns out that

FIG. 3 (e) is a schematic reference diagram of this embodiment shown for comparison with the conventional examples of (c) and (d).

The chord of the Kruga flap 6 of the present embodiment is made smaller than the chord of the conventional Kruga flap 06 shown in FIG. 4, and the reduced amount is left behind (upper) the slot 9 to the leading edge 5 of the main wing. The outer diameter of the leading edge is increased as the leading edge contour outer plate 1, and the torque tube 8 is rotated and actuated via the link mechanism 7. Therefore,
Despite the high degree of action of the embodiment described above,
Compared to the conventional Kruga flap type, it does not cause weight increase,
In addition, it has a secondary effect that the complexity of the deployment mechanism is not increased.

As described above, in the present embodiment, the kruga flap 6 is vertically provided in front of the leading edge contour outer plate 1 having the adhering streamlined laminar flow type contour, but a slat may be used instead of the kruga flap 6. Good.

Further, in the present embodiment, the link mechanism 7 is used for deploying and accommodating the front edge contour outer plate 1 and the Kruga flap 6, respectively, but the expansive and accommodating are not limited to these means, and the object of the invention is not limited. Any means may be used without departing.

Further, although the present embodiment has been described with respect to the example of the leading edge of the main wing, the object of application is not limited to the leading edge of the main wing.
For example, it may be applied to the front edge of the flap or the like. That is, it is free to be used for either the leading edge high lift device or the trailing edge high lift device.

As described above, according to the present embodiment, when the aircraft requires high lift, the aircraft is deployed at any time to form the adhering streamline laminar type contour by the enlarged state of the leading edge radius of the wing,
Furthermore, a kruga flap is hung in front of it, and the adhering streamline is switched from turbulent to laminar flow, so laminar flow can be maintained in a wide area from the leading edge to the main upper surface, and a very large lift can be created. There are advantages.

Further, there is an advantage that a large lift can be created centrally by a simple and lightweight structure.

[0048]

The present invention has the following effects configured as described above.

That is, generally, the shape profile of the leading edge portion of the main wing of the aircraft when stored in the high lift device is determined by the form and conditions at the time of cruising so that the aerodynamic efficiency and the economic effect of operation can be maximized. In such a shape, the adhering streamline of the flow is turbulent at the leading edge of the wing, and therefore the maximum lift coefficient obtained by the conventional high lift device that maximizes the shape profile during cruising. There was a limit.

According to the present invention, a new laminar flow maintaining type elevation is possible in which the shape contour of the blade leading edge portion in which the adhering streamline is turbulent type can be changed and restored so that the adhering streamline becomes laminar type. The force device exceeded the conventional maximum lift coefficient limit and made it possible to achieve a higher lift coefficient, resulting in extremely high lift. As a result, the takeoff and landing speed of the aircraft can be reduced, and thus the safety of takeoff and landing of the aircraft is improved.

Further, the operating economy is improved by shortening the takeoff and landing distance.

[Brief description of drawings]

FIG. 1 is a diagram of one embodiment of the present invention, (a) showing a high lift state (deployment), and (b) showing a cruising state (storage),

FIG. 2 is a comparison diagram of wind tunnel test results of the above-described example, a conventional example, and a comparative example,

3A and 3B are schematic diagrams illustrating the adhesion line, boundary layer, and the like of the conventional example and the above-described example, FIG. 3A is a plan view of the aircraft, and FIG. 3B is an enlarged perspective view of the enclosure B in FIG. 3A. Illustration of adhesion line,
(C) is a diagram of a conventional example when the attachment line is a turbulent flow type, (d) is a diagram of a conventional example when the attachment line is a turbulent flow type and relaminarization occurs,
(E) is a diagram of the above-mentioned embodiment in which the adhesion line shown as a reference is a laminar flow type,

FIG. 4 is a diagram of an example of a Kruga flap in a conventional high lift device, in which (a) shows a high lift state (deployment) and (b) shows a cruising state (storage),

FIG. 5 is a schematic view of four types of conventional leading edge high lift devices,
(A) is a slat, (b) is a Kruga flap,
(C) is the front edge bending, (d) is the above (b) and (c)
Figure showing each combination with

FIG. 6 is a schematic view of three types of conventional trailing edge high lift devices,
(E) shows a simple flap (stored state), (f) shows a split flap (stored state), (g) shows a slotted flap (stored state), (h) shows (e),
(I) is a diagram showing a developed state of (f) and (j) is a diagram showing a developed state of (g).

[Explanation of symbols]

 1 Leading edge outline skin 3,4 Actuator 5 Main wing leading edge 6 Kruga flap 7 Link mechanism 8 Torque tube 9 Slot

Front page continued (72) Inventor Makoto Hirahara 1-2-3 Toranomon, Minato-ku, Tokyo Toranomon Daiichi Building Within the Japan Aircraft Development Association (72) Inventor Koji Urabe 1-2-2 Toranomon, Minato-ku, Tokyo No. 3 Toranomon Daiichi Building Within the Japan Aircraft Development Association (72) Inventor Tadayuki Tanioka 10 Oemachi, Minato-ku, Nagoya City Mitsubishi Heavy Industries, Ltd. Nagoya Aerospace Systems Works (72) Inventor Suetsu Ohashi, Nagoya City Port 10 Oemachi, Ward Mitsubishi Heavy Industries Ltd., Nagoya Aerospace Systems Works (72) Inventor Junichi Miyagawa, 10 Oemachi, Minato Ward, Nagoya City Mitsubishi Heavy Industries Ltd., Nagoya Aerospace Systems Works (72) Inventor, Yuichi Maho Nagoya 10 Oe-cho, Minato-ku, Yokohama Mitsubishi Heavy Industries Ltd. Nagoya Aerospace Systems Works

Claims (1)

[Claims] 1. A high-lift device for deploying an aircraft when it requires high lift to change the contour shape of the wing to a high-lift flight state, and in front of the wing when deploying from a cruising flight state to a high-lift flight state. Either a leading edge slat or a leading edge Kruger flap formed in front of the leading edge of the airfoil with the edge contour changed from the cruise type to the adhering streamlined laminar type contour A laminar flow maintaining type high lift device characterized by comprising: