A design method for adjustable porous wave-leading edge biomimetic blades

Abstract

This invention discloses a method for designing an adjustable porous wave-leading biomimetic blade. The method includes dividing a reference blade into a fixed porous region, an adjustable porous region, an adjustable solid region, and a fixed solid region. The leading edge of the adjustable solid region is designed as a wave-leading edge, and its trailing edge is designed to match the leading edge of the fixed solid region. Similarly, the leading edge of the fixed porous region is designed as a wave-leading edge, and its trailing edge is designed to match the leading edge of the adjustable porous region. Finally, the trailing edge of the adjustable porous region is designed to match the wave configuration of the leading edge of the adjustable solid region. These components are combined to obtain the adjustable porous wave-leading biomimetic blade. The adjustable porous wave-leading biomimetic blade designed by this invention can adjust the relative position between the porous wave configuration and the solid wave configuration. Only one biomimetic blade prototype needs to be fabricated to conduct experimental research on the influence of the relative position between the two wave configurations on the noise reduction effect.

Description

Technical Field

[0001] This invention relates to the field of aerodynamic noise control technology, and in particular to an adjustable porous wave leading edge biomimetic blade design method. Background Technology

[0002] With the rapid development of the air transport industry, aircraft noise has become one of the most important technical challenges of widespread concern in the aviation sector. Aircraft noise is closely related to flight safety, environmental protection, and people's livelihoods. The noise of aircraft turbines has always been a key focus of aircraft noise research. Research on turbine noise is ongoing, but current efforts to reduce it have reached a bottleneck, as traditional noise control methods are no longer sufficient to further reduce noise. The development of bionics has provided new ideas for noise control. Based on the structure observed in owl wings, a "porous medium" bionic noise reduction configuration has been proposed; based on the protruding features of the leading edge of the humpback whale's pectoral fin, a "wave leading edge" bionic noise reduction configuration has been proposed. Numerous research papers have demonstrated that both bionic configurations can effectively suppress turbine noise.

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

[0004] In the study of porous-wave leading edge combined configurations, a biomimetic blade with a double-wave configuration of porous wave-solid wave configuration was designed. It was found that the relative position between the two wave configurations (such as trough-trough, trough-crest correspondence, etc.) has a certain impact on the noise reduction effect of the biomimetic configuration. However, in experimental research, if the relative position between the two wave configurations is to be analyzed experimentally, multiple biomimetic blades need to be fabricated, which requires a lot of time and manufacturing costs. Summary of the Invention

[0005] In view of this, the purpose of this invention is to propose an adjustable porous wave-leading edge biomimetic blade. To solve the problem of prototype fabrication in experiments with porous-wave-leading edge combined biomimetic blades, the inventors proposed a biomimetic blade composed of a porous medium with adjustable regions and a wave-leading edge. This blade can adjust the relative position between the porous wave configuration and the solid wave configuration. Only one biomimetic blade prototype needs to be fabricated to conduct experimental research on the influence of the relative position between the two wave configurations on the noise reduction effect.

[0006] To achieve the above objectives, the present invention adopts the following technical solution.

[0007] An adjustable porous wave-leading edge biomimetic blade design method includes the following steps:

[0008] S1: Divide the blade into four regions: fixed porous region, adjustable porous region, adjustable solid region and fixed solid region;

[0009] S2: Design the leading edge of the adjustable solid region as a wave-shaped leading edge, and design the trailing edge of the adjustable solid region to match the leading edge of the fixed solid region to obtain an adjustable wave-shaped solid region.

[0010] S3: Design the leading edge of the fixed porous region with a wave-shaped leading edge, and design the trailing edge of the fixed porous region to match the leading edge of the adjustable porous region, and design the trailing edge of the adjustable porous region to match the wave-shaped leading edge of the adjustable solid region.

[0011] S4: Combine the adjustable wave configuration solid region obtained in step S2 and the adjustable porous region obtained in step S3 to obtain the adjustable region in the blade.

[0012] S5, the fixed solid area and the fixed porous area obtained in step S3 are spliced ​​together with the adjustable area obtained in step S4 to obtain an adjustable porous wave leading edge biomimetic 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 0.35C from the leading edge. The area from the leading edge of the blade to 0.35C is the porous area, and the area from 0.35C to the trailing edge of the blade is the solid area.

[0015] (2) Divide the porous region at 0.12C. The area from the leading edge of the blade to 0.12C is the fixed porous region, and the area from 0.12C to 0.35C is the adjustable porous region.

[0016] (3) Streamline the blade at position 0.35C so that the leading edge of the solid region extends forward by 0.10C, and design the trailing edge of the adjustable porous region to be consistent with the leading edge of the solid region;

[0017] (4) Divide the solid area at 0.35C. The area from 0.25C to 0.35C is the adjustable solid area, and the area from 0.35C to the blade trailing edge is the fixed solid area.

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

[0019] Furthermore, step S2 specifically includes:

[0020] (1) Based on the existing wave leading edge configuration design technology, the leading edge of the adjustable solid region is designed with wave configuration. A sine function is selected to generate the wave leading edge. The amplitude of the wave leading edge is selected as 0.2C and the wavelength is 0.1C, thus obtaining the adjustable solid region of the 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 of which are designed as straight plates to facilitate the movement of the adjustable area of ​​the blade.

[0022] Further, step S3 includes:

[0023] (1) Similarly, according to the wave leading edge configuration design method used in step S2, the wave configuration design is carried out on the fixed porous region leading edge, and a sine function is selected to generate the wave leading edge. The amplitude of the wave leading edge is 0.2C and the wavelength is 0.1C, thus obtaining the porous wave leading edge configuration.

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

[0025] (3) The tail edge of the adjustable porous region is designed to be consistent with the front edge of the adjustable solid region, that is, the tail edge of the adjustable porous region is designed to be the same wave configuration as the front edge of the adjustable solid region.

[0026] Further, step S4 includes: splicing and combining the adjustable wave configuration solid region obtained in step S2 and the adjustable porous region obtained in step S3, so that the trailing edge of the adjustable solid region matches the leading edge of the adjustable porous region, thus obtaining the adjustable region in the blade.

[0027] Further, step S5 includes: splicing and combining the fixed wave leading edge porous region obtained in step S3 and the fixed solid region in step S2 with the adjustable region obtained in step S4 to obtain an adjustable porous wave leading edge biomimetic blade.

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

[0029] This invention provides an adjustable porous wave leading edge biomimetic blade, which divides the biomimetic blade into an adjustable region and a solid region. By adjusting the adjustable region of the blade, the relative position between the porous wave configuration and the solid wave configuration can be changed, satisfying the change of the relative position between the porous wave configuration and the solid wave configuration in experiments. Thus, only one biomimetic blade test piece needs to be manufactured to conduct experimental research on the influence of the relative position between the two wave configurations on the noise reduction effect. It has excellent cost-effectiveness and efficiency, and is easy to install and operate. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the reference blade in an embodiment of the present invention;

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

[0032] Figure 3 This is a cross-sectional schematic diagram of the blade after dividing it into regions in an embodiment of the present invention;

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

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

[0035] Figure 6 This is a schematic diagram showing the arrangement of the four regions of the biomimetic leaf in an embodiment of the present invention;

[0036] Figure 7 This is a schematic diagram of the adjustable regions of the biomimetic blade in an embodiment of the present invention.

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

[0038] Figure 9 This is a schematic diagram of three biomimetic blades in three different relative positions after adjustment, provided in an embodiment of the present invention.

[0039] In the figure, 1. Fixed porous region; 2. Adjustable porous region; 3. Adjustable solid region; 4. Fixed solid region; 5. Leading edge of fixed porous region; 6. Trailing edge of fixed porous region; 7. Leading edge of adjustable porous region; 8. Trailing edge of adjustable porous region; 9. Leading edge of adjustable solid region; 10. Trailing edge of adjustable solid region; 11. Leading edge of fixed solid region; 12. Trailing edge of fixed solid region; 13. Porous medium; 14. Adjustable region. Detailed Implementation

[0040] The principles and features of the present invention will be further described below with reference to the accompanying drawings. It should be understood that the examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0041] To achieve the above objectives, the present invention provides the following specific embodiments.

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

[0043] S1: Divide the blade into four regions: fixed porous region 1, adjustable porous region 2, adjustable solid region 3, and fixed solid region 4.

[0044] S2: Design the leading edge 9 of the adjustable solid region 3 as a wave leading edge, and match the configuration of the trailing edge 10 of the adjustable solid region 3 with the leading edge 11 of the fixed solid region 4 to obtain an adjustable wave configuration solid region.

[0045] S3: Design a wave-shaped leading edge 5 for the fixed porous region 1, match the trailing edge 6 of the fixed porous region 1 with the leading edge 7 of the adjustable porous region 2, and match the trailing edge 8 of the adjustable porous region 2 with the wave configuration of the leading edge 9 of the adjustable solid region 3.

[0046] S4: Join the adjustable wave-shaped solid region obtained in step S2 and the adjustable porous region obtained in step S3 end to end to obtain the adjustable region 14 in the blade, such as... Figure 7 As shown;

[0047] S5, the fixed solid region 4 and the fixed porous region obtained in step S3 are spliced ​​together with the adjustable region 14 obtained in step S4 to obtain an adjustable porous wave leading edge biomimetic blade.

[0048] In step S1, the blade is divided into four parts: a fixed porous region 1, an adjustable porous region 2, an adjustable solid region 3, and a fixed solid region 4. Specifically, it includes:

[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 0.35C from the leading edge. The area from the leading edge of the blade to 0.35C is the porous area, and the area from 0.35C to the trailing edge of the blade is the solid area.

[0050] (2) Divide the porous region at 0.12C. The area from the leading edge of the blade to 0.12C is the fixed porous region 1, and the area from 0.12C to 0.35C is the adjustable porous region 2.

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

[0052] (4) Divide the solid area at 0.35C. The area from 0.25C to 0.35C is the adjustable solid area 3, and the area from 0.35C to the blade trailing edge is the fixed solid area 4.

[0053] (5) The extension of the adjustable porous region 2 and the adjustable solid region 3 is designed to extend outward by 0.1C compared to the fixed porous region 1 and the fixed solid region 4. In this embodiment, the wavelength of the wave leading edge configuration is selected as 0.1C, ensuring that the extension of the adjustable region is at least one wavelength longer than the original blade extension, which is sufficient to meet the adjustment range requirements of the adjustable region. The final blade segmentation is as follows: Figure 2 As shown. Figure 3 The diagram schematically shows the cross-section of the blade after it has been divided into regions.

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

[0055] (1) Based on the existing wave leading edge configuration design technology, the leading edge 9 of the adjustable solid region 3 is designed with wave configuration. A sine function is selected to generate the wave leading edge. The amplitude of the wave leading edge is selected as 0.2C and the wavelength is 0.1C, thus obtaining the adjustable solid region of the wave configuration.

[0056] (2) The trailing edge of the adjustable solid region and the leading edge of the fixed solid region have the same configuration, both designed as straight plates to facilitate the movement of the adjustable area of ​​the blade. The final designed solid region is as follows: Figure 4 As shown.

[0057] In step S3, the porous region of the blade is designed. The porous region mainly includes two parts: a fixed porous region 1 and an adjustable porous region 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 region 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, thus obtaining the porous medium wave front configuration.

[0059] (2) The trailing edge of the fixed porous region and the leading edge of the adjustable porous region have the same configuration, both designed as straight plates to facilitate the movement of the adjustable part of the blade;

[0060] (3) The tail edge of the adjustable porous region maintains the same configuration as the leading edge of the adjustable solid region. In step S2, the leading edge of the adjustable solid region is designed with a biomimetic wave configuration. Therefore, the tail edge of the adjustable porous region has the same wave configuration as the leading edge of the adjustable solid region. The final designed solid region is as follows: Figure 5 As shown. Figure 6 The diagram schematically illustrates the arrangement of four regions in a biomimetic blade: a fixed porous region 1, an adjustable porous region 2, an adjustable solid region 3, and a fixed solid region 4.

[0061] The adjustable region in the blade obtained in step S4 specifically includes: splicing the adjustable wave-shaped solid region obtained in step S2 and the adjustable porous region obtained in step S3 together end to end, with the trailing edge of the adjustable solid region matching the leading edge of the adjustable porous region, thus obtaining the adjustable region 14 in the blade. The adjustable region 14 in the blade is as follows... Figure 7 As shown.

[0062] Step S5 involves designing an adjustable porous wave-leading edge biomimetic blade, specifically including: combining the fixed porous wave-leading edge region obtained in step S3 and the fixed solid region in step S2 with the adjustable region 14 obtained in step S4 to obtain the adjustable porous wave-leading edge biomimetic blade of the present invention. The final designed adjustable biomimetic blade is as follows: Figure 8 As shown.

[0063] The adjustable porous wave-leading biomimetic blade proposed in this invention is an experimental prototype. To study the impact of changes in the relative position of the porous wave-leading edge and the solid wave configuration on the blade's noise reduction effect, an adjustable region was designed. During the experiment, by directly changing the position of the adjustable region along the spanwise direction, the relative position between the two wave configurations can be altered. Figure 9 As shown, schematic diagrams of blades in three different positions are presented, including porous wave leading edge configuration and solid wave configuration.

[0064] It should be noted that the embodiments described above are merely preferred embodiments of the present invention. For those skilled in the art, various modifications, improvements, and equivalent substitutions can be made to the present invention without departing from its principles, and such modifications, improvements, and equivalent substitutions are also considered to fall within the protection scope of the claims of the present invention.

Claims

1. A method for designing an adjustable porous wave-leading biomimetic blade, characterized in that, Includes the following steps: S1: Divide the blade into four regions: fixed porous region, adjustable porous region, adjustable solid region and fixed solid region; Step S1 specifically includes: (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 0.35C from the leading edge. The area from the leading edge of the blade to 0.35C is the porous area, and the area from 0.35C to the trailing edge of the blade is the solid area. (2) Divide the porous region at 0.12C. The area from the leading edge of the blade to 0.12C is the fixed porous region, and the area from 0.12C to 0.35C is the adjustable porous region. (3) Streamline the 0.35C position of the blade so that the leading edge of the solid region extends forward by 0.10C, and design the trailing edge of the adjustable porous region and the leading edge of the solid region to have the same configuration; (4) Divide the solid region at 0.35°C, with the area from 0.25°C to 0.35°C being the adjustable solid region and the area from 0.35°C to the trailing edge of the blade being the fixed solid region; (5) The extension of the adjustable porous region and the adjustable solid region is designed to extend outward by 0.1C compared with the fixed porous region and the fixed solid region. The wavelength of the wave leading edge configuration is selected as 0.1C to ensure that the extension of the adjustable region is at least one wavelength longer than the original blade, so as to meet the adjustment range requirements of the adjustable region. S2: Design the leading edge of the adjustable solid region as a wave leading edge, and design the trailing edge of the adjustable solid region to match the leading edge of the fixed solid region to obtain an adjustable wave configuration solid region; S3: Design the leading edge of the fixed porous region with a wave-shaped leading edge, and design the trailing edge of the fixed porous region to match the leading edge of the adjustable porous region in terms of configuration, and design the trailing edge of the adjustable porous region to match the wave-shaped configuration of the leading edge of the adjustable solid region. S4: Combine the adjustable wave configuration solid region obtained in step S2 and the adjustable porous region obtained in step S3 to obtain the adjustable region in the blade. S5: Combine the fixed solid area and the fixed porous area obtained in step S3 with the adjustable area obtained in step S4 to obtain an adjustable porous wave leading edge bionic blade.

2. The adjustable porous wave-leading edge biomimetic blade design method according to claim 1, characterized in that, Step S2 specifically includes: (1) Based on the existing wave leading edge configuration design technology, the leading edge of the adjustable solid region is designed with a wave configuration, a sine function is selected to generate the wave leading edge, the amplitude of the wave leading edge is selected as 0.2C, and the wavelength is 0.1C, so as to obtain the adjustable solid region of the wave configuration; (2) The trailing edge of the adjustable solid region and the leading edge of the fixed solid region are designed to have the same configuration, both being straight plates, so as to facilitate the movement of the adjustable region of the blade.

3. The adjustable porous wave-leading edge biomimetic blade design method according to claim 1, characterized in that, Step S3 specifically includes: (1) Similarly, according to the wave leading edge configuration design method used in step S2, the wave configuration design is carried out on the fixed porous region leading edge, and a sine function is selected to generate the wave leading edge. The amplitude of the wave leading edge is 0.2C and the wavelength is 0.1C, thus obtaining the porous wave leading edge configuration. (2) The tail edge of the fixed porous area and the leading edge of the adjustable porous area are designed to be consistent, both being designed as straight plates, so as to facilitate the movement of the adjustable area of ​​the blade; (3) The tail edge of the adjustable porous region and the front edge of the adjustable solid region are designed to have the same configuration, that is, the tail edge of the adjustable porous region is designed to have the same wave configuration as the front edge of the adjustable solid region.

4. The adjustable porous wave-leading edge biomimetic blade design method according to claim 1, characterized in that, Step S4 specifically includes: splicing and combining the adjustable wave configuration solid region obtained in step S2 and the adjustable porous region obtained in step S3, so that the trailing edge of the adjustable solid region matches the leading edge of the adjustable porous region, thus obtaining the adjustable region in the blade.

5. The adjustable porous wave-leading edge biomimetic blade design method according to claim 1, characterized in that, Step S5 specifically includes: combining the fixed porous wave leading edge region obtained in step S3 and the fixed solid region obtained in step S2 with the adjustable region obtained in step S4 to obtain an adjustable porous wave leading edge biomimetic blade.

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