A precipitation estimation device based on non-newtonian fluid and helmholtz resonator

Abstract

This invention relates to a precipitation estimation device based on non-Newtonian fluids and a Helmholtz resonator, comprising a rain collector, a resonator, and a sound-receiving cavity connected sequentially from top to bottom, as well as a soundproof container encapsulating the resonator and the sound-receiving cavity. The rain collector is cylindrical, and the resonator is connected to the lower port of the rain collector. An acoustic conversion component is located at the top of the resonator, comprising two parallel, spaced horizontal thin films and a non-Newtonian fluid encapsulated between the two horizontal thin films. The sound-receiving cavity is connected to the bottom of the resonator, and its interior is used to house a microphone. This device utilizes the properties of non-Newtonian fluid dynamics to selectively transmit high-frequency raindrop signals while blocking low-frequency environmental noise, reducing noise at the source of data acquisition and avoiding the drawbacks of post-processing noise reduction in traditional algorithms.

Description

Technical Field

[0001] This invention relates to the field of acoustic acquisition and environmental monitoring technology, specifically to a precipitation estimation device based on non-Newtonian fluids and a Helmholtz resonator. Background Technology

[0002] Rainfall monitoring is a crucial foundation for meteorological observation, hydrological analysis, and geological disaster early warning. Rainfall monitoring methods based on audio acquisition have advantages such as simple structure, fast response speed, and low cost, and are widely used in simple field precipitation monitoring scenarios.

[0003] Currently, conventional rainfall monitoring or rain sound acquisition equipment has significant shortcomings in practical use. These devices struggle to accurately distinguish the effective sound signals generated by raindrop impacts from environmental noise such as human voices, vehicle horns, and wind noise. Environmental noise mixes with the rain sound signal, severely interfering with audio acquisition accuracy and significantly reducing the accuracy of subsequent data processing tasks such as rainfall intensity inversion and raindrop spectrum analysis.

[0004] Most existing noise reduction technologies rely on backend software signal processing algorithms, which can only perform post-processing filtering and noise reduction on the acquired audio signals. They cannot isolate environmental noise interference from the physical acquisition source, nor can they optimize the signal-to-noise ratio during the signal acquisition process. In complex field environments, noise reduction is ineffective, easily leading to data distortion and unstable monitoring accuracy in precipitation monitoring. Summary of the Invention

[0005] To address the technical problems existing in the background art, the present invention provides a precipitation estimation device based on non-Newtonian fluid and Helmholtz resonant cavity.

[0006] The technical solution of this invention is as follows: A precipitation estimation device based on non-Newtonian fluid and Helmholtz resonant cavity includes a rain collector, a resonant cavity and a sound receiving cavity connected in sequence from top to bottom, as well as a soundproof container that encapsulates the resonant cavity and the sound receiving cavity. The rain collector is cylindrical, and the resonant cavity is connected to the lower port of the rain collector. The top of the resonant cavity is provided with an acoustic conversion component, which includes two parallel and spaced horizontal thin films and a non-Newtonian fluid encapsulated between the two horizontal thin films. The bottom of the sound-receiving cavity is connected to the bottom of the resonating cavity, and its interior is used to house the pickup.

[0007] Furthermore, both horizontal films are made of PET material and have the same thickness, 0.15-0.25mm.

[0008] Furthermore, a pressure ring is snapped onto the top of the resonant cavity, which can clamp the acoustic conversion component onto the resonant cavity.

[0009] Furthermore, an annular platform protrudes inward from the upper part of the inner wall of the resonating cavity, and the pressure diaphragm ring engages with the inner wall of the resonating cavity, pressing the edge of the acoustic conversion component onto the annular platform.

[0010] Furthermore, the ring-shaped truncated cone extends obliquely upward from the outside in, with an inclination angle of 4°-6°.

[0011] Furthermore, the rain collector is an inverted frustum-shaped cylinder with a connecting part extending downward from the lower port edge. The resonating cavity and the soundproof container are respectively connected to the inner and outer walls of the connecting part.

[0012] Furthermore, it also includes a packaging container, with a flange ring extending outward from the upper edge of the rain collector. The flange ring presses against the upper port edge of the packaging container. The rain collector, resonant cavity, sound-receiving cavity, and soundproof container are all located inside the packaging container.

[0013] Furthermore, the top of the sound-receiving cavity is connected to the resonance cavity via a vertically installed sound guide tube.

[0014] Furthermore, the inner wall of the sound guide tube is smoothed.

[0015] Furthermore, the inner diameter of the sound guide tube is 5-7mm, and the length is 145-155mm.

[0016] The precipitation estimation device based on non-Newtonian fluid and Helmholtz resonator provided by this invention has the following beneficial effects: 1. Relying on the non-Newtonian fluid dynamics properties, it selectively transmits high-frequency raindrop signals and blocks low-frequency environmental noise, reducing noise at the source of acquisition and avoiding the drawbacks of post-processing noise reduction in traditional algorithms.

[0017] 2. The Helmholtz resonator is used to amplify the characteristic signal of rain sound, and the sound is transmitted in a low-loss manner through a sound guide tube to improve the sensitivity of the acquisition and the accuracy of precipitation measurement.

[0018] 3. The double-enclosure design isolates vibration noise and protects internal precision components, making it suitable for complex and harsh monitoring environments. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the device of the present invention; Figure 2 This is a schematic diagram showing the rain collector, resonating cavity, and sound receiving cavity of the present invention in an exploded state. Figure 3 This is a schematic diagram of the dual-container system of the present invention.

[0020] The components represented by the various reference numerals in the diagram are: 1. Rain collector; 11. Connecting part; 12. Flange ring; 2. Resonating cavity; 21. Circular stage; 3. Sound receiving cavity; 4. Sound insulation container; 5. Acoustic conversion component; 6. Pressure diaphragm ring; 7. Sound guide tube; 8. Encapsulation container. Detailed Implementation

[0021] like Figure 1 , Figure 2 , Figure 3 As shown, this invention provides a precipitation estimation device based on non-Newtonian fluids and a Helmholtz resonant cavity, comprising a rain collector 1, a resonant cavity 2, and a sound receiving cavity coaxially assembled from top to bottom, and a soundproof encapsulation structure to isolate external air noise. The following detailed description is provided in conjunction with the accompanying drawings and specific embodiments.

[0022] Example 1 Rain collector 1 is used to receive and guide raindrops. Rain collector 1 is preferably made of butyl rubber, which has a high damping coefficient and is not prone to vibration and noise, thus avoiding noise generated by rainwater hitting the shell. It also has outdoor adaptability characteristics such as aging resistance, waterproofing, and resistance to high and low temperatures.

[0023] The rain collector 1 is an inverted frustum-shaped cylindrical structure, which is open from top to bottom to increase the rain collection range. The preferred dimensions of the rain collector 1 are an outer diameter of 200 mm at the top, an outer diameter of 120 mm at the bottom, a vertical height of 90 mm, and a wall thickness of 2 mm.

[0024] The lower port edge of the rain collector 1 has a cylindrical connecting part 11 extending downwards, and the resonating cavity 2 is connected to the inner wall of the connecting part 11. The extension length of the connecting part 11 is preferably 13 mm.

[0025] Specifically, the inner wall of the connecting part 11 is provided with an internal thread, and the upper part of the outer wall of the resonance cavity 2 is provided with an external thread. The resonance cavity 2 is stably connected to the rain collector 1 through the threaded connection.

[0026] In this embodiment, the soundproof enclosure structure is a soundproof container 4, which is a barrel-shaped container with an open top. The upper end of the soundproof container 4 is tightly fitted onto the outside of the rain collector 1 connecting part 11, and connected to the rain collector 1 by an interference fit. The resonance cavity 2 and the sound receiving cavity 3 are both located inside the soundproof container 4. The soundproof container 4 isolates environmental noise and protects both of them, preventing raindrops from hitting at an angle and generating additional noise. The soundproof container 4 is preferably made of butyl rubber material, and its dimensions are preferably an inner diameter of 124 mm, a height of 298 mm, and a wall thickness of 3 mm.

[0027] The resonant cavity 2 is used to transmit the sound of raindrops and reduce the transmission of environmental noise. In this embodiment, the resonant cavity 2 is a cylindrical hollow box with an open top. It is preferably made of rigid PVC-U (unplasticized polyvinyl chloride) tubing, which has high rigidity, does not vibrate with environmental sound waves, and has a smooth inner wall, eliminating sound absorption loss and maximizing the retention of the internal sound signal. The dimensions of the resonant cavity 2 are preferably a vertical height of 33mm, an inner wall thickness of 2mm, and an inner diameter of 116mm.

[0028] The top of the resonating cavity 2 is provided with an acoustic conversion component 5 as a seal, so that the resonating cavity 2 forms a sealed cavity. The acoustic conversion component 5 includes two horizontally spaced parallel thin films and a non-Newtonian fluid encapsulated between the two horizontal thin films.

[0029] In this design, the two horizontal films have identical parameters, meaning they are identical in shape, size, and material. Both horizontal films are preferably made of PET (polyethylene terephthalate), a material with high areal density and moderate rigidity. It possesses extremely strong acoustic impedance to low-to-mid-frequency airborne sound waves such as human voices and vehicle horns, making it less susceptible to vibration driven by air pressure waves, thus significantly reducing the amount of airborne environmental noise entering the cavity. Simultaneously, PET material has low brittleness and good toughness, making it extremely sensitive to high-speed point-like impacts from raindrops. It can generate instantaneous local bending vibrations, accurately capturing the raindrop impact signal and efficiently coupling these instantaneous local bending vibrations into the air within the resonant cavity 2. The two horizontal films have the same thickness, ranging from 0.15 to 0.25 mm; in this embodiment, 0.2 mm is preferred.

[0030] A shear-thickening non-Newtonian fluid is sealed between two horizontal thin films. The fluid mass ratio is as follows: 50% deionized water as the main solvent, 42% corn starch as the core shear thickener, 4% glycerol for water retention and viscosity enhancement, 3.5% PEG-400 (polyethylene glycol-400) for evaporation inhibition, 0.8% sodium hyaluronate for water retention and sedimentation mitigation, and 0.2% composite preservative for corrosion and mildew prevention. This fluid is a soft liquid at room temperature. When raindrops act with pulsed, localized high shear force on the upper horizontal film, the non-Newtonian fluid instantly undergoes shear thickening and hardens, efficiently transmitting mechanical force to the lower horizontal film, thereby driving air vibration within the resonant cavity 2 to generate sound waves. When uniform sound waves from the environment act on the surface of the upper horizontal film, the non-Newtonian fluid remains liquid, dissipating sound wave energy through its viscosity without producing an overall hardening response. This effectively blocks environmental noise transmitted through the air from entering the resonant cavity 2, achieving physical sieving and noise reduction.

[0031] In this embodiment, the vertical distance between the lower horizontal film and the bottom wall of the resonant cavity 2 is optimized to 30 mm. At this height, the sound wave signal generated by the raindrop impact is the strongest, and the resonant modes of the cavity itself are the fewest, thus achieving the best signal-to-noise ratio. The resonant cavity constitutes the main body of the Helmholtz resonant cavity, which can selectively amplify sound waves of specific frequencies.

[0032] Furthermore, an annular platform 21 protrudes inward from the upper part of the inner wall of the resonating cavity 2 to support the acoustic conversion component 5. A pressure diaphragm ring 6 is also provided at the top of the resonating cavity 2. The pressure diaphragm ring 6 presses the edge of the acoustic conversion component 5 onto the annular platform 21, and together with the annular platform 21, replaceably fixes the acoustic conversion component 5 onto the resonating cavity 2. The pressure diaphragm ring 6 can be fastened to the inner wall of the resonating cavity 2 through an interference fit or a snap-fit ​​structure. The edges of the upper and lower horizontal films are fixed by mechanical clamping, ensuring that the horizontal films remain flat and form an airtight seal to prevent sound energy leakage.

[0033] Specifically, the annular platform 21 is formed on the inner wall of the resonating cavity 2 at a position 3 mm from the upper end section. The dimensions of the annular platform 21 are preferably 8 mm wide and 2 mm thick. The pressure ring 6 is made of butyl rubber material, and its dimensions are preferably 100 mm inner diameter, 8 mm ring width, and 3 mm thickness.

[0034] Furthermore, to ensure the flatness of the horizontal film, the annular platform 21 extends obliquely upward from the outside in, with an angle preferably of 4°-6°, that is, the annular platform 21 is slightly conical. In this way, when the pressing ring 6 is pressed down, it is beneficial to subject the edge of the horizontal film to an oblique outward force, thereby helping to ensure the flatness of the horizontal film.

[0035] In this embodiment, the top of the sound-receiving cavity 3 is connected to the resonating cavity 2 via a vertically arranged sound guide tube 7. Specifically, a connecting hole is provided at the center of the bottom wall of the resonating cavity 2, and the upper end of the sound guide tube 7 is detachably and tightly connected to the connecting hole by means of interference fit, snap-fit, or threaded connection. The sound-receiving cavity 3 is a cavity structure composed of an inverted funnel-shaped upper cavity and a cylindrical lower cavity. A connecting tube extends upward from the upper port edge of the upper cavity, and the lower end of the sound guide tube 7 is detachably and tightly connected to the connecting tube by means of interference fit, snap-fit, or threaded connection.

[0036] More specifically, the sound guide tube 7 is made of rigid PVC-U material with an inner diameter of 5-7mm, which can achieve the best transient impact conduction effect and effectively cut off high-frequency noise, resulting in the highest signal-to-noise ratio. Its length is designed to be 145-155mm to attenuate external noise to the greatest extent while ensuring signal fidelity and preventing the generation of cavity standing waves, thus ensuring pure signal transmission.

[0037] In this embodiment, the dimensions of the sound guide tube 7 are preferably 6mm inner diameter, 150mm length, and 2mm wall thickness.

[0038] In addition, the inner wall of the sound guide tube 7 is smoothed to reduce frictional loss of sound waves during transmission.

[0039] The sound receiving cavity 3 is also made of rigid PVC-U material. Its preferred dimensions are: inner diameter of the lower cavity 68mm, height 45mm, and wall thickness 4mm, and height of the upper cavity 15mm and wall thickness 3mm.

[0040] The internal space of the sound receiving cavity 3 is used to place microphones and other pickups. Specifically, the pickups are placed in the lower cavity, and the funnel-shaped upper cavity can efficiently transmit the sound energy from the sound guide tube 7 to the pickups, realizing the conversion of sound energy into electrical signals.

[0041] Example 2 This embodiment further includes a sealing container 8 based on embodiment 1. The sealing container 8 is a barrel-shaped structure with an open top, and the rain collector 1, the resonance cavity 2, the sound receiving cavity 3, and the sound insulation container 4 are all located inside the sealing container 8. A flange ring 12 extends outward from the upper edge of the rain collector 1, and the flange ring 12 presses against the upper port edge of the sealing container 8, so that a sealed cavity is formed inside the sealing container 8.

[0042] Specifically, the outer shell is also made of butyl rubber, and its dimensions are preferably 204 mm inner diameter, 210 mm outer diameter, 398 mm height, and 3 mm wall thickness. The flange ring 12 is preferably 20 mm wide and 4 mm thick.

[0043] This embodiment further isolates external environmental noise by using the encapsulation container 8 as the outermost protective shell. The encapsulation container 8 and the soundproof container 4 form a double-barrier cavity, providing a pure acoustic acquisition environment for the internal acoustic components and isolating external environmental noise from intrusion from the sides and bottom.

[0044] In addition, in some embodiments, sound-insulating material can be filled in the space between the encapsulation container 8 and the soundproof container 4 to enhance the sound insulation effect.

Claims

1. A precipitation estimation device based on non-Newtonian fluid and Helmholtz resonator, characterized by, It includes a rain collector (1), a resonating cavity (2) and a sound receiving cavity (3) connected from top to bottom, and a soundproof container (4) that encapsulates the resonating cavity (2) and the sound receiving cavity (3). The rain collector (1) is cylindrical, the resonating cavity (2) is connected to the lower port of the rain collector (1), and the top of the resonating cavity (2) is provided with an acoustic conversion component (5). The acoustic conversion component (5) includes two horizontal thin films arranged in parallel and spaced apart and a non-Newtonian fluid encapsulated between the two horizontal thin films. The sound-receiving cavity (3) is connected to the bottom of the resonance cavity (2), and its interior is used to house the pickup.

2. A device for estimating precipitation based on a non-Newtonian fluid and a Helmholtz resonator as claimed in claim 1, characterized in that, Both horizontal films are made of PET material and have the same thickness of 0.15-0.25 mm.

3. A precipitation estimation device based on a non-Newtonian fluid and a Helmholtz resonator according to claim 1 or 2, characterized in that, The top of the resonating cavity (2) is fitted with a pressure ring (6), which can hold the acoustic conversion component (5) on the resonating cavity (2).

4. A device for estimating precipitation based on a non-Newtonian fluid and a Helmholtz resonator as claimed in claim 3, characterized in that, The upper part of the inner wall of the resonance cavity (2) has an annular platform (21) protruding inward. The pressure film ring (6) is engaged with the inner wall of the resonance cavity (2) and presses the edge of the acoustic conversion component (5) onto the annular platform (21).

5. A device for estimating precipitation based on a non-Newtonian fluid and a Helmholtz resonator as claimed in claim 4, characterized in that, The annular platform (21) extends obliquely upward from the outside to the inside, with an inclination angle of 4°-6°.

6. The precipitation estimation device based on non-Newtonian fluid and Helmholtz resonator as described in claim 1, characterized in that, The rain collector (1) is an inverted frustum-shaped cylinder with a connecting part (11) extending downward from the lower port edge. The resonating cavity (2) and the soundproof container (4) are respectively connected to the inner and outer walls of the connecting part (11).

7. The precipitation estimation device based on non-Newtonian fluid and Helmholtz resonator as described in claim 6, characterized in that, It also includes a packaging container (8), and a flange ring (12) extends outward from the upper edge of the rain collector (1). The flange ring (12) presses on the upper port edge of the packaging container (8). The rain collector (1), the resonance cavity (2), the sound receiving cavity (3) and the sound insulation container (4) are all located inside the packaging container (8).

8. The precipitation estimation device based on non-Newtonian fluid and Helmholtz resonator as described in claim 1, characterized in that, The top of the sound receiving cavity (3) is connected to the resonance cavity (2) through a vertically arranged sound guide tube (7).

9. A precipitation estimation device based on non-Newtonian fluid and Helmholtz resonator as described in claim 8, characterized in that, The inner wall of the sound guide tube (7) is smoothed.

10. A precipitation estimation device based on non-Newtonian fluid and Helmholtz resonator as described in claim 9, characterized in that, The sound guide tube (7) has an inner diameter of 5-7 mm and a length of 145-155 mm.

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