RU2294300C2 - Lifting surface - Google Patents

Abstract

FIELD: aviation.

SUBSTANCE: proposed aerodynamic lifting surface has both sides which are wavy in span in form of humps and cavities. Parameters of waviness: waviness period h=5-30% of chord, relative doubled amplitude f=1-5% of chord, length of wavy surface section along chord g=15-85% beginning with front edge; the remaining surface is smooth. Humps and cavities on both sides of lifting surface relative to profile chord coincide in phase.

EFFECT: improved aerodynamic efficiency.

4 cl, 3 dwg

Description

The invention relates to the field of aviation and wind energy and may find application as an aerodynamic or hydrodynamic surface creating a lifting force, for example, an airplane wing, a helicopter blade or a rotor blade of a wind power installation.

Known aircraft with a wing in the form of a plate, uniform in profile, pointed at the front. On the upper surface of the plate there are longitudinal ribs forming horizontal wave-like channels (Patent RU No. 2190557, MKI B 64 C 21/10).

The disadvantage of an aircraft with the wing described above is its low aerodynamic quality and low critical angle of attack of the wing, at which the flow stalls.

The closest prototype to the proposed technical solution is the wing described in patent RU No. 2128601, where the method for controlling stall on the aerodynamic surface of the direct wing is carried out by changing the flow around this surface due to the retractable elements installed along the entire span of the wing.

This allows you to control the separation flow on the wing surface. That is, when the protrusions extend at large angles of attack of the wing, flow stall from the leading edge is eliminated, and thus the critical angle of attack of the wing increases, to which it retains its load-bearing properties.

However, this solution has disadvantages. Since at small angles of attack of the wing, the protrusions impede optimal flow around them, they have to be removed inside the wing, which complicates its design.

The proposed technical solution - a bearing surface with a sweep in scope in the form of humps and depressions - allows you to optimally affect the stall and increase the lifting force, for example, the wings of an airplane.

Studies have shown that a wing with a wavy sweeping surface has large critical angles of attack and a higher aerodynamic quality compared to a wing with a smooth surface with the same profile during subsonic flow.

In order to realize this advantage on the wings of other aircraft, as well as on the blades of propellers, it is proposed to make the bearing surface wavy in scope, in the form of humps and depressions.

The objective of the invention is to increase the aerodynamic quality of the bearing surface and increase the critical angle of attack.

The problem is solved due to the fact that both sides of the bearing surface are made wavy in scope in the form of humps and depressions, and the waviness parameters are set with the following ratio: wavage period h = 5 ÷ 30% of the chord; relative doubled amplitude f = 1 ÷ 5% of the chord; the length of the section with a wavy surface along the chord g = 15 ÷ 85%, starting from the leading edge, and the rest of the surface is made smooth.

The position of the humps and undulations of the undulation on both sides of the bearing surface relative to the chord of the profile can be made to coincide in phase or with an arbitrary shift.

The waviness parameters on both sides of the bearing surface relative to the profile chord can be the same or different.

The configuration of the humps and troughs of the undulation is given in any form.

These features are not identified in other technical solutions when studying the level of this technical field, and, therefore, the solution is new and has an inventive step.

Figure 1 shows a section of a wavy bearing surface. Figure 2 shows a variety of midsection section AA of the bearing surface.

Figure 3 shows a three-dimensional image of the wing.

The bearing surface that creates the lifting force can be manufactured using any technology that is used to create aircraft wings, helicopter blades and propellers of wind power plants. The profiles of the bearing surface are selected taking into account its purpose and working conditions. The essence of the invention is to give the bearing surface, starting from the leading edge and ending with a distance g = 15 ÷ 85% along the chord of the bearing surface, waviness over the entire range (figure 1). The undulation parameters should lie in the following limits: the undulation period h = 5 ÷ 30% of the chord (Fig. 1, 2), the relative doubled amplitude f = 1 ÷ 5% of the chord (Fig. 2), the length of the section with a wavy surface g may make up, starting from the leading edge from 15 to 85%, then the wavy surface smoothly turns into a smooth one. The rest of the surface is smooth (figure 1). This form of the bearing surface allows to increase its critical angles of attack and aerodynamic quality during subsonic flow.

Claims (4)

1. Aerodynamic surface, for example, an airplane wing, characterized in that both surfaces are made wavy in scope in the form of humps and depressions and have undulation parameters: undulation period h = 5 ÷ 30% of the chord; relative doubled amplitude f = 1 ÷ 5% of the chord; the length of the section with a wavy surface along the chord g = 15 ÷ 85%, starting from the leading edge, while the shape of the corrugation profile is made of any configuration, and the rest of the surface is made smooth. 2. The aerodynamic surface according to claim 1, characterized in that the positions of the humps and depressions on both sides relative to the profile chord coincide in phase. 3. The aerodynamic surface according to claim 1 or 2, characterized in that the waviness parameters on both surfaces with respect to the profile chord are the same. 4. The aerodynamic surface according to claim 1 or 2, characterized in that the waviness parameters on both surfaces relative to the profile chord are made different.

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