A propeller blade with noise reduction function

Abstract

This invention relates to the field of aircraft component technology, and more particularly to a propeller blade with noise reduction functionality. The blade incorporates a noise reduction structure as filling material, comprising interconnected absorption and reflection layers. Based on the principle of energy conversion, noise causes air to vibrate within the noise reduction layer, resulting in energy conversion. The energy carried by the noise is transformed into heat and deformation energy, which is ultimately dissipated within the blade. This invention essentially does not alter the aerodynamic shape of the propeller, effectively suppressing propeller noise without compromising its aerodynamic performance. The propeller blade with this noise reduction function is lightweight, simple in structure, maintenance-free, and economical.

Description

Technical Field

[0001] This invention relates to the field of aircraft component technology, and in particular to a propeller blade with noise reduction function. Background Technology

[0002] With the booming development of the tourism market, tourism using manned airships as a means of sightseeing has developed rapidly. However, while people use airships for sightseeing, the noise pollution they generate has become a significant issue, affecting the passenger experience and hindering the further promotion of manned airships.

[0003] The noise from the propellers is a major problem and has attracted worldwide attention. This noise negatively impacts normal tourism, and at certain frequencies, it can even harm human health. Because the propellers cause unsteady flow, the resulting noise is unavoidable.

[0004] The main component of propeller noise is rotational noise, which is mainly composed of thickness noise and load noise. Studying the origin and laws of noise and finding ways to control noise has become an urgent problem to be solved.

[0005] Therefore, developing effective technologies related to propeller noise reduction is of great significance for the further development of manned airships. For manned airships using propellers as propellers, noise reduction methods used in propeller-driven aircraft and other aircraft with rotating structures can be referenced. Increasing the number of propeller blades can reduce the outer diameter of the propeller while maintaining power characteristics, thereby lowering the relative Mach number at the blade tip. Through related design, changing the shape of the propeller can shift the aerodynamic load towards the inner diameter, achieving noise reduction. Alternatively, reducing the blade area can decrease the relative thickness of the blades, thus significantly reducing noise.

[0006] In summary, current methods for suppressing propeller noise primarily involve altering the number and shape of the propeller blades, which impacts the original propeller design. Therefore, building upon biomimetic noise reduction techniques, applying noise suppression structures inside the propeller has significant practical value and broad application prospects for further noise reduction. Summary of the Invention

[0007] The purpose of this invention is to provide a propeller blade with noise reduction function, which applies a noise suppression structure from the perspective of the propeller's internal structure to solve the noise problem of airship propellers.

[0008] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0009] This invention provides a propeller blade with noise reduction function, including a blade body;

[0010] A noise reduction structure is provided on the blade surface of the blade body;

[0011] The noise reduction structure includes an absorption layer and a reflective layer that are interconnected;

[0012] The absorption layer includes a horizontal sound-absorbing tube bundle and a vertical sound-absorbing tube bundle, wherein the horizontal sound-absorbing tube bundle and the vertical sound-absorbing tube bundle are perpendicularly connected to each other;

[0013] The reflective layer is located at the bottom of the absorption layer, and an arc-shaped structure connected to the vertical sound-absorbing tube bundle is prefabricated on the reflective layer.

[0014] Furthermore, the transverse sound-absorbing tube bundle has a horizontal honeycomb structure;

[0015] The vertical sound-absorbing tube bundle has a vertical honeycomb structure.

[0016] Furthermore, the vertical honeycomb structure has a side length of 6.6mm-7.4mm and a height of 3.8mm-4.2mm; the distance of the vertical honeycomb structure along the chord of the propeller blade is 5.2mm-5.6mm.

[0017] Furthermore, the side length of the horizontal honeycomb structure is half the height of the vertical honeycomb structure, and its length is 4.6mm-5mm. Its center is on the same horizontal plane as the center of the vertical honeycomb structure.

[0018] Furthermore, according to the claim, the propeller blade with noise reduction function is characterized in that: the arc-shaped structure is an arc-shaped groove structure with a semi-circular cross-section, and the radius of the semi-circular cross-section is the diameter of a single hole on the vertical honeycomb structure.

[0019] Furthermore, the noise reduction structure is arranged within 15%-50% of the propeller blade span and is located on the surface of the blade profile corresponding to the leading edge to 60% of the chord length.

[0020] Furthermore, the material used in the noise reduction structure (1) is a porous sound-absorbing material;

[0021] Or / and, the noise reduction structure is made of foam, which is made by perforation;

[0022] Or / and, after the propeller is formed by a mold, the noise reduction structure (1) is attached to its interior, and finally the propeller is closed.

[0023] Compared with existing technologies, the beneficial technical effects of this invention are as follows: In this application, a noise-reducing structure is used as the filling material inside the propeller blade. This noise-reducing structure includes an interconnected absorption layer and a reflection layer. Based on the principle of energy conversion, noise causes air to vibrate within the noise-reducing layer. During this process, energy conversion occurs, transforming the energy carried by the noise into heat energy and deformation energy, which is ultimately dissipated within the propeller blade. This invention essentially does not alter the aerodynamic shape of the propeller, effectively suppressing the noise generated by the propeller without changing its aerodynamic performance. The propeller blade with the above-mentioned noise-reducing function is lightweight, simple in structure, maintenance-free, and economical. Attached Figure Description

[0024] The present invention will be further described below with reference to the accompanying drawings.

[0025] Figure 1 Three-view diagram of the propeller blades;

[0026] Figure 2 This is a cross-sectional view of AA.

[0027] Figure 3 It is an absorption layer;

[0028] Figure 4 This is a cross-sectional view of BB. Detailed Implementation

[0029] like Figure 1-4 As shown, a propeller blade with noise reduction function includes a blade body;

[0030] A noise reduction structure 1 is embedded on the blade surface of the blade body;

[0031] The noise reduction structure 1 includes an absorption layer 2 and a reflective layer 5 that are interconnected.

[0032] The absorption layer 2 includes a horizontal sound-absorbing tube bundle and a vertical sound-absorbing tube bundle, and the horizontal sound-absorbing tube bundle and the vertical sound-absorbing tube bundle are perpendicularly connected to each other.

[0033] The reflective layer 5 is located at the bottom of the absorption layer 2, and an arc-shaped structure 6 connected to the vertical sound-absorbing tube bundle is prefabricated on the reflective layer 5.

[0034] In this embodiment, the transverse sound-absorbing tube bundle is a horizontal honeycomb structure 4; the vertical sound-absorbing tube bundle is a vertical honeycomb structure 3.

[0035] In this embodiment, the side length of the vertical honeycomb structure 3 is 6.6mm-7.4mm, and its height is 3.8mm-4.2mm; the distance of the vertical honeycomb structure 3 along the chord of the propeller blade is 5.2mm-5.6mm.

[0036] In this embodiment, the side length of the horizontal honeycomb structure 4 is half the height of the vertical honeycomb structure 3, and its length is 4.6mm-5mm. Its center is on the same horizontal plane as the center of the vertical honeycomb structure 3.

[0037] In this embodiment, the arc-shaped structure 6 is an arc-shaped groove structure with a semi-circular cross-section. The radius of the semi-circular cross-section is the diameter of a single hole on the vertical honeycomb structure 3, so that the vertical honeycomb structure 3 can introduce sound waves into the arc-shaped structure 6.

[0038] In this embodiment, the noise reduction structure 1 is arranged in the range of 15%-50% of the propeller blade span and is located on the surface of the blade profile corresponding to the leading edge to 60% of the chord length.

[0039] In this embodiment, the material used for the noise reduction structure 1 is a porous sound-absorbing material; specifically, the material of the noise reduction structure is foam, which is made by hollowing out; after the propeller is formed by a mold, the noise reduction structure (1) is attached to its interior, and finally the propeller is closed.

[0040] Example 2

[0041] A propeller blade with noise reduction function has a noise reduction structure 1 as the filling material inside the blade. The noise reduction structure includes an absorption layer 2 and a reflective layer 5, which are interconnected. The absorption layer is a regular hexagonal honeycomb structure. The vertical honeycomb structure 3 of the absorption layer has a side length of 6.6mm-7.4mm and a height of 3.8mm-4.2mm. The horizontal honeycomb structure 4 of the absorption layer has a side length of half the height of the vertical honeycomb structure 3 and a length of 4.6mm-5mm. Its center is on the same horizontal plane as the center of the vertical honeycomb structure 3. The distance between the vertical honeycomb structures 3 and the chord of the propeller blade is 5.2mm-5.6mm. The reflective layer is a smooth arc-shaped structure 6 with a circular cross-section. The radius of the circular cross-section is the side length of the vertical honeycomb structure 3. The noise reduction structure 1 is arranged within 15%-50% of the propeller blade span, on the surface of the blade cross-section corresponding to 60% of the chord length from the leading edge.

[0042] The noise reduction principle of this invention is as follows: When the propeller rotates, it generates noise. This noise enters the absorption layer 2, causing air vibration in the vertical honeycomb structure 3. This causes the vertical honeycomb structure 3 to deform, converting some of the noise energy into internal energy and dissipating it. The remaining noise enters the horizontal honeycomb structure 4 for further absorption. Because the vertical honeycomb structure 3 and the horizontal honeycomb structure 4 are different in size, they absorb noise of different frequency bands, increasing the noise reduction effect. Finally, the noise enters the reflection layer 5, where the arc-shaped structure 6 forces any undissipated noise to re-enter the absorption layer. This process repeats, reducing noise levels.

[0043] During the test, the propeller with the above noise reduction structure was compared with an ordinary propeller, and the sound pressure level was measured. The results showed that the propeller with the noise reduction structure was 18dB quieter than the ordinary propeller.

[0044] The above embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A propeller blade with noise reduction function, characterized in that: Including the blade body; A noise reduction structure (1) is provided on the blade surface of the blade body. The noise reduction structure (1) includes an absorption layer (2) and a reflective layer (5) that are interconnected. The absorption layer (2) includes a horizontal sound-absorbing tube bundle and a vertical sound-absorbing tube bundle, wherein the horizontal sound-absorbing tube bundle and the vertical sound-absorbing tube bundle are perpendicularly connected to each other; The reflective layer (5) is located at the bottom of the absorption layer (2), and an arc-shaped structure (6) connected to the vertical sound-absorbing tube bundle is prefabricated on the reflective layer (5).

2. The propeller blade with noise reduction function according to claim 1, characterized in that: The transverse sound-absorbing tube bundle is a horizontal honeycomb structure (4). The vertical sound-absorbing tube bundle is a vertical honeycomb structure (3).

3. The propeller blade with noise reduction function according to claim 2, characterized in that: The vertical honeycomb structure (3) has a side length of 6.6mm-7.4mm and a height of 3.8mm-4.2mm; the vertical honeycomb structure (3) is 5.2mm-5.6mm away from the propeller blade chord.

4. The propeller blade with noise reduction function according to claim 3, characterized in that: The side length of the horizontal honeycomb structure (4) is half the height of the vertical honeycomb structure (3), and its length is 4.6mm-5mm. Its center is on the same horizontal plane as the center of the vertical honeycomb structure (3).

5. The propeller blade with noise reduction function according to claim 2, characterized in that: The arc-shaped structure (6) is an arc-shaped groove structure with a semi-circular cross-section. The radius of the semi-circular cross-section is the diameter of a single hole on the vertical honeycomb structure (3).

6. The propeller blade with noise reduction function according to claim 1, characterized in that: The noise reduction structure (1) is arranged in the range of 15%-50% of the propeller blade span and is located on the surface of the blade profile corresponding to the leading edge to 60% of the chord length.

7. The propeller blade with noise reduction function according to claim 1, characterized in that: The material used in the noise reduction structure (1) is a porous sound-absorbing material; Or / and, the noise reduction structure is made of foam, which is made by perforation; Or / and, after the propeller is formed by a mold, the noise reduction structure (1) is attached to its interior, and finally the propeller is closed.

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