Silencing device based on acoustic metamaterial, and demonstration device and demonstration method thereof

Abstract

The invention provides a silencing device based on an acoustic metamaterial. The silencing device comprises an outer shell and a plurality of spiral baffles, a perforated pipe which is coaxial with the outer shell is arranged in the outer shell, the perforated pipe is arranged between the opposite side surfaces of the outer shell in a penetrating mode, and a cavity for containing the spiral baffles is formed between the outer shell and the perforated pipe. The plurality of spiral baffles are circumferentially arrayed at equal angles along the central shaft to divide the cavity; and silencing holes are formed in the inner wall of the perforated pipe and the inner sides of the spiral baffles and are arranged along the central shaft in an equal-angle circumferential array manner. The demonstration device comprises a PVC pipe, a loudspeaker and a sound level meter, the loudspeaker and a silencing device are installed at the two ends of the PVC pipe respectively, the silencing device wraps the side surfaces of the corresponding ends of the PVC pipe through a clamping plate, the sound level meter is arranged at the end, opposite to the loudspeaker, of the PVC pipe, and the silencing effect of the silencing device is obtained according to the upgrade difference detected by the sound level meter through a comparison test. The device is good in demonstration effect and large in noise elimination amount.

Description

technical field [0001] The invention relates to the field of laser noise reduction devices, in particular to a noise reduction device based on acoustic metamaterials, a demonstration device and a demonstration method thereof. Background technique [0002] The current sound barrier structure is relatively thick, heavy and does not have the function of air circulation. The use of porous materials for sound absorption will cause pollution; the sound absorption frequency of the louver sound barrier is relatively low, and the microporous sound barrier has poor stability. In snowy weather, the sound absorption capacity of the sound barrier is severely reduced due to water ingress inside the sound barrier, and sound reflection problems exist in ordinary transparent sound barriers. [0003] The patent of invention with the publication number CN108979816A discloses a noise reduction device, which uses baffles in the airflow channel and sound-absorbing cotton in the cavity to continuo...

AI Technical Summary

Problems solved by technology

[0002] The current sound barrier structure is relatively thick, heavy and does not have the function of air circulation. The use of porous materials for sound absorption will cause pollution; the sound absorption frequency of the louver sound barrier is relatively low, and the microporous sound barrier has poor stability. In snowy weather, water entering the sound barrier causes a serious drop in sound absorption capacity, and ordinary transparent sound barriers have problems with sound reflection, etc.

[0003] The patent of invention with the publication number CN108979816A discloses a noise reduction device, which uses baffles in the airflow channel and sound-absorbing cotton in the cavity to continuously attenuate the energy of the airflow in the noise reduction pipe and play the role of noise reduction. The baffle will affect the circulation of the air flow. When water enters the interior, the sound absorption capacity of the sound-absorbing cotton will be seriously reduced, and the weight of the sound-absorbing device will be increased.

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