Unmanned aerial vehicle rotor based on sawtooth and wedge complex noise reduction

Abstract

The utility model discloses a kind of unmanned aerial vehicle rotors based on sawtooth and wedge composite noise reduction, it is related to unmanned aerial vehicle technical field.Specifically including rotor body, the rotor body has leading edge, trailing edge and pressure surface, the leading edge and trailing edge of the rotor body are respectively provided with leading edge sawtooth structure and trailing edge sawtooth structure;The pressure surface of the rotor body is provided with multiple wedge structures spaced apart along its spanwise arrangement;The wedge structure is triangular projection, the bottom of each described wedge structure is coincident with the rotor trailing edge, and the tip of wedge structure extends towards the rotor leading edge direction.It aims at designing a kind of unmanned aerial vehicle rotor, which can synergistically inhibit multiple noise sources, achieve wideband noise reduction and not significantly sacrifice aerodynamic performance.

Description

Technical Field

[0001] This utility model relates to the field of unmanned aerial vehicle (UAV) technology, and in particular to a UAV rotor based on a composite noise reduction method using sawtooth and wedge-shaped blades. Background Technology

[0002] Drones are increasingly widely used in modern society, covering multiple scenarios such as aerial photography, logistics, and inspection. However, during flight, the high-speed rotation of the drone's rotor and its interaction with the air generate significant aerodynamic noise, which greatly limits its application in noise-sensitive environments such as cities and residential areas. The sources of rotor noise are complex, mainly including broadband noise generated by the interaction between the leading edge of the blade and the turbulent flow, as well as discrete noise formed by eddy shedding within the boundary layer at the trailing edge of the blade.

[0003] In existing technologies, passive flow control methods are often used to reduce rotor noise, such as serrifying only the trailing edge of the rotor. This approach can suppress specific noise peaks to some extent by changing the coherence of trailing edge vortex shedding. However, this type of approach only targets the single noise source at the trailing edge, and its effect on suppressing other major noise sources such as leading edge noise is limited. The overall noise reduction level is not high, and sometimes the aerodynamic efficiency of the rotor itself is sacrificed for noise reduction, which is not worthwhile.

[0004] Therefore, designing a UAV rotor capable of synergistically suppressing multiple noise sources, achieving broadband noise reduction, and not significantly sacrificing aerodynamic performance has become a pressing technical challenge. Utility Model Content

[0005] The main purpose of this invention is to provide a drone rotor based on a combination of sawtooth and wedge noise reduction, aiming to design a drone rotor that can synergistically suppress multiple noise sources, achieve wideband noise reduction, and not significantly sacrifice aerodynamic performance.

[0006] To achieve the above objectives, this utility model proposes a drone rotor based on a composite noise reduction method using sawtooth and wedge structures. The rotor body includes a rotor body with a leading edge, a trailing edge, and a pressure surface. A leading edge sawtooth structure and a trailing edge sawtooth structure are respectively provided on the leading and trailing edges of the rotor body. Multiple wedge structures are arranged at intervals along the span of the pressure surface of the rotor body. Each wedge structure is a triangular protrusion, with the bottom of each wedge structure coinciding with the trailing edge of the rotor, and the tip of the wedge structure extending towards the leading edge of the rotor.

[0007] Preferably, the leading edge serrated structure is disposed on the leading edge of the rotor body via a first transition member.

[0008] Preferably, the tilt angles of the first transition member and the leading edge sawtooth structure are consistent with the angle of attack of the rotor body at the corresponding cross-section.

[0009] Preferably, the height of the leading edge serration is 5mm, the horizontal width is 4mm, and the horizontal distance between two adjacent leading edge serrations is 1mm.

[0010] Preferably, the leading edge serration structure has a distribution length of 130 mm along the rotor span.

[0011] Preferably, the trailing edge serrated structure is disposed on the trailing edge of the rotor body via a second transition member.

[0012] Preferably, the tilt angle of the second transition member and the trailing edge serrated structure is consistent with the trailing edge angle of the rotor body.

[0013] Preferably, the height of the trailing edge serration is 5mm, the horizontal width is 4mm, and the horizontal distance between two adjacent trailing edge serrations is 1mm.

[0014] Preferably, the trailing edge serration structure has a distribution length of 150 mm along the rotor span.

[0015] Preferably, the bottom width of each wedge structure is 3mm, and the horizontal spacing between two adjacent wedge structures is 3mm.

[0016] The above-mentioned technical solution has the following advantages: the leading-edge serrated structure can pre-process the incoming flow to reduce leading-edge noise; subsequently, the wedge structure on the pressure surface suppresses the development of surface turbulence noise by interfering with boundary layer flow; finally, the trailing-edge serrated structure is used to suppress trailing-edge vortex shedding noise. This comprehensive design integrates multiple noise reduction structures into one, and its overall noise reduction effect is far superior to any single noise reduction structure. Moreover, it can achieve significant broadband noise reduction without significantly affecting the rotor's lift and other basic aerodynamic performance. Attached Figure Description

[0017] The present invention will now be described in detail with reference to specific embodiments and accompanying drawings, wherein: Figure 1 This is a three-dimensional structural diagram of a drone rotor according to an embodiment of the present utility model; Figure 2 for Figure 1 The diagram shows a top view of the rotor structure of the UAV. Figure 3 for Figure 1 The diagram shows a bottom-view structural diagram of the UAV rotor. Figure 4 for Figure 3 A magnified view of a portion of point A in the middle; Figure 5 for Figure 3 A magnified view of a portion of point B in the middle; Figure 6 for Figure 3 A magnified view of a portion of point C. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this application clearer, the specific embodiments of this application will be described in detail below with reference to the accompanying drawings. It should be noted that the specific embodiments described herein are merely illustrative of this application and not intended to limit it.

[0019] When a drone performs a mission, its rotor rotates at high speed and interacts with the air, which is the main source of noise for the aircraft. The generation mechanism of rotor aerodynamic noise is very complex, typically including turbulent noise generated by the interaction between the leading edge of the blade and the incoming airflow, and noise generated by vortex shedding at the trailing edge of the blade. These noises have a wide frequency spectrum, which seriously affects the application of drones in acoustically sensitive environments such as cities. Existing technologies often only target the suppression of a single noise source, such as modifying only the trailing edge, resulting in limited noise reduction effects and potentially sacrificing other sources, or even the aerodynamic efficiency of the rotor. This application provides a composite noise reduction scheme that integrates multiple noise reduction structures at key locations on the rotor to synergistically suppress multiple core noise sources, achieving significant broadband noise reduction without significantly affecting aerodynamic performance.

[0020] Referring to the accompanying drawings, this application provides a drone rotor based on a composite noise reduction method using sawtooth and wedge serrations.

[0021] Example 1 Please see Figures 1 to 6 The UAV rotor of this embodiment includes a rotor body 1. The rotor body 1 is the basic airfoil structure constituting the rotor, having a leading edge 11 for cutting through the air, a trailing edge 12 for airflow to converge and fall off, a suction surface 13 on the upper surface, and a pressure surface 14 on the lower surface. To achieve composite noise reduction, a leading edge serrated structure 2, a trailing edge serrated structure 3, and a wedge structure 4 are integrated on the rotor body 1.

[0022] A leading-edge serrated structure 2 is disposed on the leading edge 11 of the rotor body 1. To ensure a smooth transition of airflow to the serrated region and reduce flow separation, a first transition member 21 is provided between the leading edge 11 of the rotor body 1 and the leading-edge serrated structure 2. In this embodiment, the first transition member 21 can be a smooth protrusion integrally extended outward from the leading edge 11. To ensure that the leading-edge serrated structure 2 can effectively act on the incoming flow under different flight attitudes, the overall tilt angle of the first transition member 21 and the leading-edge serrated structure 2 is consistent with the angle of attack of the rotor body 1 at the corresponding cross-section. This design ensures that the serrations can interact with the airflow at the optimal angle, thereby effectively breaking the large-scale turbulent structure into multiple small-scale vortices, reducing the intensity of leading-edge noise at its source. In a preferred embodiment, the height H1 of a single leading-edge serration is 5 mm, the horizontal width W1 is 4 mm, and the horizontal distance D1 between two adjacent leading-edge serrations is 1 mm. These dimensional parameters have been optimized to achieve a good vortex breaking effect while ensuring structural strength. The leading edge sawtooth structure 2 is not distributed along the entire rotor span, but is concentrated in the area that contributes the most to noise. Its distribution length L1 along the rotor span is 130mm, which achieves a balance between noise reduction effect and aerodynamic influence.

[0023] A trailing edge serrated structure 3 is disposed on the trailing edge 12 of the rotor body 1. Similar to the leading edge, to achieve a smooth transition of the structure, the trailing edge serrated structure 3 is disposed on the trailing edge of the rotor body 1 via a second transition member 31. The tilt angle of the second transition member 31 and the trailing edge serrated structure 3 is consistent with the trailing edge angle of the rotor body 1. This design helps to guide the boundary layer airflow smoothly towards the serrations and detach, thereby effectively changing the coherence of vortex shedding, dispersing the concentrated sound energy over a wider frequency range, and reducing the noise peak in the frequency band sensitive to the human ear. In a preferred embodiment, the height H2 of a single trailing edge serration is 5 mm, the horizontal width W2 is 4 mm, and the horizontal distance D2 between two adjacent trailing edge serrations is also 1 mm. Its distribution length L2 along the rotor span is 150 mm. The outward extension length of the first transition member 21 and the second transition member 31 is 1 mm.

[0024] The wedge structure 4 is another key feature of this application for achieving composite noise reduction. Multiple wedge structures 4 are arranged at spanwise intervals on the pressure surface 14 of the rotor body 1. The wedge structure 4 is a triangular protrusion, with the bottom 41 of each wedge structure 4 coinciding with the trailing edge 12 of the rotor, and the tip 42 of the wedge structure 4 extending towards the leading edge 11 of the rotor. Preferably, the tips 42 of the wedge structures are located on the same horizontal line CL. This arrangement allows the wedge structures 4 to effectively act on the boundary layer flow near the trailing edge of the pressure surface 14, actively interfering with and disrupting the formation of large-scale coherent structures within the boundary layer by introducing spanwise flow vortices, further suppressing turbulent noise flowing through the pressure surface. In one specific embodiment, the bottom width W3 of a single wedge structure 4 is 3 mm, the horizontal interval D3 between two adjacent wedge structures 4 is 3 mm, and the distribution width L3 of this series of wedge structures along the rotor spanwise is 70 mm. The presence of these wedge structures 4 compensates for the shortcomings of traditional noise-reducing rotors that only focus on the leading and trailing edges while ignoring the flow on the blade surface.

[0025] In this embodiment, the leading-edge serrated structure 2, the trailing-edge serrated structure 3, and the wedge structure 4 work together. When the rotor rotates, the leading-edge serrated structure 2 first pre-processes the incoming flow, weakening the leading-edge noise; subsequently, the airflow passing through the pressure surface 14 is disturbed by the wedge structure 4, suppressing the development of surface turbulence noise; finally, the airflow detaches at the trailing edge 12 through the trailing-edge serrated structure 3, suppressing trailing-edge vortex shedding noise. This multi-stage, all-round noise reduction design achieves multi-source, multi-level suppression of wideband aerodynamic noise of the rotor, with a comprehensive noise reduction effect far superior to any single noise reduction structure. At the same time, due to the ingenious design of the dimensions of each structure, it has little impact on the rotor's lift and other basic aerodynamic performance.

[0026] Example 2 Another embodiment of this application is largely the same as the previous embodiment, except that the specific dimensional parameters of the noise reduction structure can be adaptively adjusted according to the size of the UAV, the rotor speed, and the target noise reduction frequency band. For example, for small UAVs requiring higher rotational speeds, whose noise frequencies are higher, the heights H1 and H2 of the leading and trailing edge serrations, and the horizontal widths W1 and W2 can be appropriately reduced, while the distribution density can be increased, i.e., the horizontal spacing D1 and D2 between adjacent serrations can be reduced. Simultaneously, the wedge structure 4 on the pressure surface 14 can also employ different bottom widths W3, horizontal spacings D3, or spanwise distribution widths L3 to match the boundary layer characteristics under different operating conditions. These adaptive adjustments all fall within the scope of the protection concept of this application. By adjusting these micro-geometric parameters, the composite noise reduction rotor of this application can be flexibly adapted to different types and applications of UAV platforms, exhibiting broad applicability.

[0027] The above description is only a preferred embodiment of the present utility model and does not limit the patent scope of the present utility model. All equivalent structural transformations made under the inventive concept of the present utility model using the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

Claims

1. A UAV rotor based on a combination of sawtooth and wedge noise reduction, characterized in that, The rotor body includes a leading edge, a trailing edge, and a pressure surface. The leading edge and trailing edge of the rotor body are respectively provided with a leading edge serrated structure and a trailing edge serrated structure. The pressure surface of the rotor body is provided with a plurality of wedge structures arranged at intervals along its span. The wedge structure is a triangular protrusion, and the bottom of each wedge structure coincides with the trailing edge of the rotor, and the tip of the wedge structure extends towards the leading edge of the rotor.

2. The UAV rotor based on sawtooth and wedge composite noise reduction as described in claim 1, characterized in that, The leading edge serrated structure is disposed on the leading edge of the rotor body via a first transition member.

3. The UAV rotor based on sawtooth and wedge composite noise reduction as described in claim 2, characterized in that, The tilt angles of the first transition member and the leading edge sawtooth structure are consistent with the angle of attack of the rotor body at the corresponding cross section.

4. The UAV rotor based on sawtooth and wedge composite noise reduction as described in claim 3, characterized in that, The height of the leading edge serration is 5mm, the horizontal width is 4mm, and the horizontal distance between two adjacent leading edge serrations is 1mm.

5. The UAV rotor based on sawtooth and wedge composite noise reduction as described in claim 4, characterized in that, The leading edge sawtooth structure has a distribution length of 130 mm along the rotor span.

6. The UAV rotor based on sawtooth and wedge composite noise reduction as described in claim 1, characterized in that, The trailing edge serrated structure is disposed on the trailing edge of the rotor body via a second transition piece.

7. The UAV rotor based on sawtooth and wedge composite noise reduction as described in claim 6, characterized in that, The tilt angles of the second transition member and the trailing edge serrated structure are consistent with the trailing edge angle of the rotor body.

8. The UAV rotor based on sawtooth and wedge composite noise reduction as described in claim 7, characterized in that, The height of the trailing edge serration is 5mm, the horizontal width is 4mm, and the horizontal distance between two adjacent trailing edge serrations is 1mm.

9. The UAV rotor based on sawtooth and wedge composite noise reduction as described in claim 8, characterized in that, The trailing edge serrated structure has a distribution length of 150 mm along the rotor span.

10. The UAV rotor based on sawtooth and wedge composite noise reduction as described in claim 1, characterized in that, Each of the wedge structures has a bottom width of 3 mm, and the horizontal spacing between two adjacent wedge structures is 3 mm.

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