Design method of adjustable porous wave front edge bionic blade

Abstract

The invention discloses a design method of an adjustable porous wave front edge bionic blade. The design method comprises the steps that a reference blade is divided into a fixed porous area, an adjustable porous area, an adjustable entity area and a fixed entity area; the front edge of the adjustable solid area is subjected to wave front edge design, the tail edge of the adjustable solid area is designed to be matched with the front edge of the fixed solid area in configuration, the front edge of the fixed porous area is subjected to wave front edge design, and the tail edge of the fixed porous area is designed to be matched with the front edge of the adjustable porous area in configuration; the wave configuration of the tail edge of the adjustable porous area and the wave configuration of the front edge of the adjustable solid area are designed to be matched, and all the parts are combined to obtain the adjustable porous wave front edge bionic blade. According to the adjustable porous wave front bionic blade designed by the method, the relative position between the porous wave configuration and the solid wave configuration can be adjusted, and the experimental research on the influence of the relative position between the two wave configurations on the noise reduction effect can be carried out only by processing one bionic blade test piece.

Description

Technical Field

[0001] The invention relates to the technical field of aerodynamic noise control, and in particular to a design method for an adjustable porous wave leading edge bionic blade. Background Art

[0002] With the rapid development of the air transport industry, aircraft noise has become one of the important technical problems that are of general concern to the aviation community. Aircraft noise is closely related to flight safety, environmental protection, people's livelihood and other issues. The noise of aircraft turbines has always been the focus of attention on aircraft noise. Research on turbine noise is constantly being carried out. At present, the research on reducing turbine noise has entered a bottleneck period. Traditional noise control methods can no longer reduce noise further. The development of bionics has provided new ideas for noise control. Based on the structure observed in the wings of owls, a "porous medium" bionic noise reduction configuration was proposed. Based on the protruding characteristics of the leading edge of the humpback whale's pectoral fin, a "wave leading edge" bionic noise reduction configuration was proposed. A large number of research literatures have proved that both bionic configurations can effectively suppress turbine noise.

[0003] However, it is difficult to further reduce noise efficiently through a single bionic configuration. In the study of cylindrical airfoils, it was found that the wavy leading edge is more effective in suppressing broadband noise, while the porous leading edge is more effective in suppressing single-tone noise. The porous wavy leading edge has a significant suppressing effect on both single-tone noise and broadband noise. This shows that the combined design of porous medium and wavy leading edge can retain the advantages of wavy leading edge and porous medium in suppressing noise. Therefore, the porous-wavy leading edge combination configuration is a bionic configuration with great noise reduction potential.

[0004] Research on porous-wave leading edge combinations resulted in the design of a bionic blade with a dual-wave configuration: a porous wave and a solid wave. It was discovered that the relative position of the two waves (e.g., trough-to-trough, trough-to-peak correspondence) influences the noise reduction effect of the bionic blade. However, experimental analysis of the relative position of the two waves requires the fabrication of multiple bionic blades, which consumes significant time and expense. Summary of the Invention

[0005] In light of this, the present invention aims to propose an adjustable porous wave-leading-edge bionic blade. To address the challenges of fabricating test specimens for combined porous and wave-leading-edge bionic blades, the inventors proposed a bionic blade composed of a porous medium with an adjustable area and a wave-leading edge. This design allows for adjustment of the relative position between the porous wave configuration and the solid wave configuration. By fabricating only one bionic blade test specimen, experimental research can be conducted to investigate the effect of the relative position of the two wave configurations on noise reduction.

[0006] In order to achieve the above-mentioned purpose, the present invention adopts the following technical solutions.

[0007] A method for designing an adjustable porous wavy leading edge bionic blade comprises the following steps:

[0008] S1: The blade is divided into four regions, namely fixed porous region, adjustable porous region, adjustable solid region and fixed solid region;

[0009] S2: Designing a wave leading edge on the leading edge of the adjustable solid area, and designing the trailing edge of the adjustable solid area to match the leading edge of the fixed solid area in configuration, thereby obtaining an adjustable wave configuration solid area;

[0010] S3: Designing a wavy leading edge for the leading edge of the fixed porous region, designing the trailing edge of the fixed porous region to match the leading edge of the adjustable porous region in configuration, and designing the trailing edge of the adjustable porous region to match the wavy configuration of the leading edge of the adjustable solid region;

[0011] S4: splicing and combining the adjustable wave configuration solid area obtained in step S2 and the adjustable porous area obtained in step S3 to obtain an adjustable area in the blade;

[0012] S5, combining the fixed solid area, the fixed porous area obtained in step S3, and the adjustable area obtained in step S4 to obtain an adjustable porous wavy leading edge bionic blade.

[0013] Furthermore, step S1 specifically includes:

[0014] (1) Select a reference blade and obtain the average chord length C of the blade. Divide the blade into two parts at a distance of 0.35° from the leading edge. The area from the leading edge to 0.35° is the porous area, and the area from 0.35° to the trailing edge is the solid area.

[0015] (2) The porous area is divided at 0.12°C, with the area from the leading edge of the blade to 0.12°C as the fixed porous area and the area from 0.12°C to 0.35°C as the adjustable porous area;

[0016] (3) The blade 0.35° position is streamlined so that the leading edge of the solid area extends forward 0.10°, and the trailing edge of the adjustable porous area is designed to have the same configuration as the leading edge of the solid area;

[0017] (4) The solid area is divided at the position of 0.35C, 0.25C to 0.35C is the adjustable solid area, and 0.35C to the trailing edge of the blade is the fixed solid area;

[0018] (5) The length of the adjustable porous area and the adjustable solid area is designed to extend outward by 0.1C compared to the fixed porous area and the fixed solid area, and the wavelength of the wave leading edge configuration is selected as 0.1C to ensure that the length of the adjustable area is at least one wavelength longer than the length of the original blade, so as to be sufficient to meet the range requirements of the adjustable area.

[0019] Furthermore, step S2 specifically includes:

[0020] (1) According to the existing wave front configuration design technology, the front edge of the adjustable solid area is designed with a wave configuration, and a sine function is selected to generate the wave front edge. The amplitude of the wave front edge is selected as 0.2C and the wavelength is 0.1C, thereby obtaining an adjustable solid area with a wave configuration;

[0021] (2) The trailing edge of the adjustable solid area and the leading edge of the fixed solid area are designed to have the same configuration, both designed to be straight plate-shaped, to facilitate the movement of the adjustable area of ​​the blade.

[0022] Furthermore, step S3 includes:

[0023] (1) Also according to the wave front configuration design method used in step S2, the wave configuration design is performed on the front edge of the fixed porous area, and a sine function is selected to generate the wave front edge. The amplitude of the wave front edge is 0.2C and the wavelength is 0.1C, and the porous wave front edge configuration is obtained;

[0024] (2) The trailing edge of the fixed porous area and the leading edge of the adjustable porous area are designed to have the same configuration, both designed to be straight, to facilitate the movement of the adjustable area of ​​the blade;

[0025] (3) The trailing edge of the adjustable porous region is designed to have the same configuration as the leading edge of the adjustable solid region, that is, the trailing edge of the adjustable porous region is designed to have the same wave configuration as the leading edge of the adjustable solid region.

[0026] Furthermore, step S4 includes: splicing and combining the adjustable wave configuration solid area obtained in step S2 and the adjustable porous area obtained in step S3 so that the trailing edge of the adjustable solid area fits with the leading edge of the adjustable porous area, thereby obtaining the adjustable area in the blade.

[0027] Furthermore, step S5 includes: splicing and combining the fixed wave leading edge porous area obtained in step S3, the fixed solid area in step S2, and the adjustable area obtained in step S4, so as to obtain an adjustable porous wave leading edge bionic blade.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] The present invention provides an adjustable porous wave leading edge bionic blade, which divides the bionic blade into an adjustable area and a solid area. By adjusting the adjustable area in the blade, the relative position between the porous wave configuration and the solid wave configuration is changed to meet the change of the relative position between the porous wave configuration and the solid wave configuration in the experiment. Therefore, only one bionic blade test piece needs to be processed to conduct experimental research on the influence of the relative position between the two wave configurations on the noise reduction effect. The bionic blade has excellent cost-effectiveness and is easy to install and convenient to operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic diagram of a reference blade according to an embodiment of the present invention;

[0031] Figure 2 This is a schematic diagram of a blade divided into regions in an embodiment of the present invention;

[0032] Figure 3 is a schematic cross-sectional view of a blade divided into regions in an embodiment of the present invention;

[0033] Figure 4 This is a schematic diagram of the wave configuration design of the entity area in an embodiment of the present invention;

[0034] Figure 5 This is a schematic diagram of the porous area design in an embodiment of the present invention;

[0035] Figure 6 Schematic diagram of the arrangement of four regions of a bionic blade in an embodiment of the present invention;

[0036] Figure 7 Schematic diagram of the combination of adjustable areas of a bionic blade in an embodiment of the present invention;

[0037] Figure 8 A schematic diagram of a bionic blade provided by an embodiment of the present invention;

[0038] Figure 9 Schematic diagram of a bionic blade in three different relative positions after adjustment provided by an embodiment of the present invention.

[0039] In the figure, 1. fixed porous area; 2. adjustable porous area; 3. adjustable solid area; 4. fixed solid area; 5. leading edge of fixed porous area; 6. trailing edge of fixed porous area; 7. leading edge of adjustable porous area; 8. trailing edge of adjustable porous area; 9. leading edge of adjustable solid area; 10. trailing edge of adjustable solid area; 11. leading edge of fixed solid area; 12. trailing edge of fixed solid area; 13. porous medium; 14. adjustable area. DETAILED DESCRIPTION

[0040] The principles and features of the present invention are further described below in conjunction with the accompanying drawings. It should be understood that the examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0041] In order to achieve the above objectives, the present invention provides the following specific embodiments.

[0042] like Figure 1-2 As shown, an embodiment of the present invention provides a design method for an adjustable porous wavy leading edge bionic blade, comprising the following steps:

[0043] S1: The blade is divided into four regions: fixed porous region 1, adjustable porous region 2, adjustable solid region 3 and fixed solid region 4;

[0044] S2: The leading edge 9 of the adjustable solid area 3 is designed as a wave leading edge, and the trailing edge 10 of the adjustable solid area 3 matches the configuration of the leading edge 11 of the fixed solid area 4 to obtain an adjustable wave configuration solid area;

[0045] S3: The leading edge 5 of the fixed porous area 1 is designed with a wavy leading edge, the trailing edge 6 of the fixed porous area 1 matches the leading edge 7 of the adjustable porous area 2, and the trailing edge 8 of the adjustable porous area 2 matches the wavy configuration of the leading edge 9 of the adjustable solid area 3;

[0046] S4: Splice the adjustable wave configuration solid area obtained in step S2 and the adjustable porous area obtained in step S3 together end to end to obtain the adjustable area 14 in the blade, such as Figure 7 As shown;

[0047] S5, splicing the fixed solid area 4, the fixed porous area obtained in step S3, and the adjustable area 14 obtained in step S4 together at the head and tail, thereby obtaining an adjustable porous wavy leading edge bionic blade.

[0048] In step S1, the blade is divided into four parts: a fixed porous area 1, an adjustable porous area 2, an adjustable solid area 3 and a fixed solid area 4, specifically including:

[0049] (1) Select a reference blade and obtain the average chord length C of the blade. Divide the blade into two parts at a distance of 0.35° from the leading edge. The area from the leading edge to 0.35° is the porous area, and the area from 0.35° to the trailing edge is the solid area.

[0050] (2) The porous area is divided at 0.12°C, with the leading edge of the blade to 0.12°C as the fixed porous area 1, and the area from 0.12°C to 0.35°C as the adjustable porous area 2;

[0051] (3) In order to reduce the loss of blade aerodynamic performance, the solid part 0.35C position is streamlined, such as Figure 2 As shown in , the leading edge of the solid area is extended forward by 0.10C. In order for the blades to be finally assembled together, the configurations of the trailing edge 8 of the adjustable porous area 2 and the leading edge 9 of the adjustable solid area 3 need to be consistent;

[0052] (4) The solid area is divided at the position of 0.35C, 0.25C to 0.35C is the adjustable solid area 3, and 0.35C to the trailing edge of the blade is the fixed solid area 4;

[0053] (5) The length of the adjustable porous region 2 and the adjustable solid region 3 is designed to extend outward by 0.1° compared to the fixed porous region 1 and the fixed solid region 4. The wavelength of the wave leading edge configuration in this embodiment is selected to be 0.1°, ensuring that the length of the adjustable region is at least one wavelength longer than the length of the original blade, so as to meet the range requirements of the adjustable region. The final segmentation of the blade is as follows: Figure 2 shown. Figure 3 FIG. 3 schematically shows a cross section of a blade after region division.

[0054] In step S2, the physical area of ​​the blade is designed. The physical area mainly includes two parts: an adjustable physical area 3 and a fixed physical area 4. The design method specifically includes the following steps:

[0055] (1) According to the existing wave front configuration design technology, the front edge 9 of the adjustable solid area 3 is designed with a wave configuration, and a sine function is selected to generate the wave front. The amplitude of the wave front is selected as 0.2C and the wavelength is 0.1C, thereby obtaining an adjustable solid area with a wave configuration;

[0056] (2) The trailing edge of the adjustable solid area is consistent with the leading edge of the fixed solid area, and both are designed to be straight to facilitate the movement of the adjustable area of ​​the blade. The final designed solid area is as follows Figure 4 shown.

[0057] In step S3, the porous area of ​​the blade is designed. The porous area mainly includes two parts: a fixed porous area 1 and an adjustable porous area 2. The design method specifically includes the following steps:

[0058] (1) Similarly, according to the wave front configuration design method used in step S2, the wave configuration of the fixed porous area front 3 is designed, and a sine function is selected to generate the wave front. The amplitude of the wave front is 0.2C and the wavelength is 0.1C, and the wave front configuration of the porous medium is obtained;

[0059] (2) The trailing edge of the fixed porous area and the leading edge of the adjustable porous area are designed to be consistent and are both straight to facilitate the movement of the adjustable part of the blade;

[0060] (3) The trailing edge of the adjustable porous region is consistent with the leading edge of the adjustable solid region. In step S2, the leading edge of the adjustable solid region is designed to be a bionic wave configuration, so the trailing edge of the adjustable porous region is the same wave configuration as the leading edge of the adjustable solid region. The final designed solid region is as follows: Figure 5 shown. Figure 6 Schematically shows the arrangement of the four regions of the bionic blade, namely the fixed porous region 1, the adjustable porous region 2, the adjustable solid region 3 and the fixed solid region 4.

[0061] The step S4 is to obtain the adjustable area in the blade, specifically comprising: splicing the adjustable wave configuration solid area obtained in step S2 and the adjustable porous area obtained in step S3 together end to end, and matching the trailing edge of the adjustable solid area with the leading edge of the adjustable porous area to obtain the adjustable area 14 in the blade. The adjustable area 14 in the blade is as follows: Figure 7 shown.

[0062] The step S5 is to design an adjustable porous wave leading edge bionic blade, specifically comprising: splicing and combining the fixed wave leading edge porous area obtained in step S3, the fixed solid area in step S2, and the adjustable area 14 obtained in step S4 to obtain the adjustable porous wave leading edge bionic blade of the present invention. The final designed adjustable bionic blade is as follows: Figure 8 shown.

[0063] The adjustable porous wave leading edge bionic blade proposed in this invention is a test piece. In order to study the effect of the change in the relative position of the porous wave leading edge and the solid wave configuration on the noise reduction effect of the blade, an adjustable area is designed. During the experiment, the relative position between the two wave configurations can be changed by directly changing the position of the adjustable area along the span direction. Figure 9 As shown, schematic diagrams of blades in three different positions of porous wave leading edge configuration and solid wave configuration are given.

[0064] It should be noted that the above-described embodiments are merely preferred embodiments of the present invention. Persons skilled in the art will appreciate that various modifications, improvements, and equivalent substitutions may be made to the present invention without departing from the principles of the present invention, and such modifications, improvements, and equivalent substitutions are deemed to fall within the scope of protection of the claims of the present invention.

Claims

1. A method for designing an adjustable porous wave leading edge bionic blade, characterized in that: The following steps are involved: S1: The blade is divided into four regions, namely, a fixed porous region, an adjustable porous region, an adjustable solid region, and a fixed solid region; S2: Designing the leading edge of the adjustable solid area into a wave leading edge, and designing the trailing edge of the adjustable solid area to match the leading edge of the fixed solid area in configuration, thereby obtaining an adjustable wave configuration solid area; S3: Designing a wavy leading edge for the leading edge of the fixed porous region, and designing the trailing edge of the fixed porous region to match the leading edge of the adjustable porous region in configuration, and designing the trailing edge of the adjustable porous region to match the wavy configuration of the leading edge of the adjustable solid region; S4: splicing and combining the adjustable wave configuration solid area obtained in step S2 and the adjustable porous area obtained in step S3 to obtain an adjustable area in the blade; S5: splicing and combining the fixed solid area, the fixed porous area obtained in step S3, and the adjustable area obtained in step S4 to obtain an adjustable porous wave leading edge bionic blade.

2. The adjustable porous wave leading edge bionic blade design method according to claim 1, characterized in that: The step S1 specifically includes: (1) A reference blade is selected to obtain the average chord length C of the blade. The blade is divided into two parts at a distance of 0.35° from the leading edge. The area from the leading edge of the blade to 0.35° is a porous area, and the area from 0.35° to the trailing edge of the blade is a solid area. (2) The porous area is divided at 0.12C, the area from the leading edge of the blade to 0.12C is a fixed porous area, and the area from 0.12C to 0.35C is an adjustable porous area; (3) The 0.35° position of the blade is streamlined so that the leading edge of the solid area extends forward by 0.10°, and the trailing edge of the adjustable porous area is designed to have the same configuration as the leading edge of the solid area; (4) The solid area is divided at the 0.35C position, 0.25C to 0.35C is an adjustable solid area, and 0.35C to the trailing edge of the blade is a fixed solid area; (5) The lengths of the adjustable porous area and the adjustable solid area are designed to extend outward by 0.1C compared with the fixed porous area and the fixed solid area, and the wavelength of the wave leading edge configuration is selected to be 0.1C, ensuring that the length of the adjustable area is at least one wavelength longer than the length of the original blade, so as to be sufficient to meet the adjustment range requirements of the adjustable area.

3. The adjustable porous wave leading edge bionic blade design method according to claim 1, characterized in that: The step S2 specifically includes: (1) According to the existing wave front edge configuration design technology, the front edge of the adjustable solid area is subjected to wave configuration design, a sine function is selected to generate the wave front edge, the amplitude of the wave front edge is selected to be 0.2C, and the wavelength is 0.1C, to obtain an adjustable solid area of ​​wave configuration; (2) The trailing edge of the adjustable solid area and the leading edge of the fixed solid area are designed to have a consistent configuration, and both are designed to be straight plate-shaped, so as to facilitate the movement of the adjustable area of ​​the blade.

4. The adjustable porous wave leading edge bionic blade design method according to claim 1, characterized in that: The step S3 specifically includes: (1) Also according to the wave front configuration design method used in step S2, the wave configuration design is performed on the front edge of the fixed porous area, a sine function is selected to generate the wave front edge, the amplitude of the wave front edge is 0.2C, and the wavelength is 0.1C, to obtain a porous wave front edge configuration; (2) The trailing edge of the fixed porous area and the leading edge of the adjustable porous area are designed to be consistent in configuration, and both are designed to be straight plate-shaped to facilitate the movement of the adjustable area of ​​the blade; (3) The trailing edge of the adjustable porous region is designed to have the same configuration as the leading edge of the adjustable solid region, that is, the trailing edge of the adjustable porous region is designed to have the same wave configuration as the leading edge of the adjustable solid region.

5. The adjustable porous wave leading edge bionic blade design method according to claim 1, characterized in that: The step S4 specifically includes: splicing and combining the adjustable wave configuration solid area obtained in step S2 and the adjustable porous area obtained in step S3, so that the trailing edge of the adjustable solid area matches the leading edge of the adjustable porous area, that is, obtaining the adjustable area in the blade.

6. The adjustable porous wave leading edge bionic blade design method according to claim 1, characterized in that: The step S5 specifically includes: splicing and combining the fixed wave leading edge porous area obtained in step S3, the fixed solid area in step S2 and the adjustable area obtained in step S4, so as to obtain an adjustable porous wave leading edge bionic blade.

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