Double-working mode acoustic liner for broadband noise suppression and control method

A double-working mode and noise suppression technology, which is applied to transducer circuits, sensors, electrical components, etc., can solve the problems that the acoustic lining cannot effectively suppress noise, the system is large in size, and the dynamic response is slow, so as to facilitate system integration and small size The effects of sizing, widening the frequency band range, and frequency bandwidth

Active Publication Date: 2016-08-17
ZHONGBEI UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0008] In order to overcome the fact that the existing acoustic lining cannot effectively suppress noise in a wide frequency band, and the sound absorption coefficient of the acoustic lining is not limited by the frequency of the sound source, the system volume is large and the dynamic response is slow. The application in unmanned aerial vehicles will be limited and other problems, and a sound lining and control method with dual working modes for broadband noise suppression are provided

Method used

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  • Double-working mode acoustic liner for broadband noise suppression and control method
  • Double-working mode acoustic liner for broadband noise suppression and control method
  • Double-working mode acoustic liner for broadband noise suppression and control method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0028] Embodiment 1: as Figure 1-4 As shown in the figure, an acoustic lining with dual working modes for broadband noise suppression includes an acoustic pipeline 1 with an array of annular grooves around it, the center of the acoustic pipeline 1 is perforated for the acoustic lining, and the front end of the acoustic pipeline 1 is provided with a microphone mounting hole 6, and the microphone A microphone 7 is installed in the installation hole 6; a resonant cavity 3 is arranged at intervals on the wall of the acoustic pipeline 1, the bottom of the resonant cavity 3 is provided with a spout 5 to the perforation of the acoustic lining, and the top of the resonant cavity 3 is provided with a bonding groove 4, and the top of the bonding groove 4 is bonded A vibrating diaphragm 8, a piezoelectric material 9 is installed on the vibrating diaphragm 8, an upper electrode 10 and a lower electrode 11 are respectively installed on the top and side walls of the piezoelectric material 9...

experiment example 1

[0037] Experimental Example 1: Piezoelectric acoustic lining works in the volume adjustment mode (static mode): the thickness of the nozzle 5 is 3mm, the diameter is 1mm, the depth of the resonant cavity 3 is 1mm, and the diameter of the resonant cavity 3 is 35mm. According to the formula (1), the acoustic The resonance frequency at this time is f 0 =720Hz.

[0038] A direct current within 30V is passed between the upper electrode and the lower electrode of the piezoelectric material, and the piezoelectric material deforms, driving the vibrating diaphragm to deform upward or downward, and the volume of the cavity changes accordingly to realize the adjustment of the resonance frequency. The transmission loss of the system at this time is obtained through the measurement of the microphone, and the frequency corresponding to the maximum value of the transmission loss is the resonance frequency f of the piezoelectric acoustic lining 0 . Record the magnitude of the applied DC vol...

experiment example 2

[0041] Experimental example 2: Piezoelectric acoustic lining works in volume adjustment mode (static mode): the thickness of the nozzle 5 is 3mm, the diameter is 1mm, the depth of the resonant cavity 3 is 1mm, and the diameter is 35mm. The resonance frequency of the acoustic lining is calculated according to formula (1) for f 0 =720Hz.

[0042] The working conditions of the piezoelectric acoustic lining are as follows: Figure 6 . When the frequency f of airflow noise 13 12 =726 Hz, the acoustic lining works in volume adjustment (static mode), which is greater than the resonance frequency f of the acoustic lining resonant cavity 3 0 (i.e. f 12 > f 0 ),Inquire Figure 8 , find the voltage value corresponding to 726Hz. , input a -15V DC voltage between the upper electrode 10 and the lower electrode 11 of the acoustic liner, and the piezoelectric material 9 shrinks and deforms after being driven by the negative voltage, driving the vibrating diaphragm 8 to be concave, resu...

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PUM

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Abstract

The invention belongs to the technical field of noise control, and provides a double-working mode acoustic liner for broadband noise suppression and a control method in order to overcome the problems that the existing acoustic liner cannot realize effective noise suppression in a relatively wide band range; when the acoustic absorptivity of the acoustic liner is not restricted by acoustic source frequency, the system is relatively large in volume and relatively slow in dynamic response; and the application of the acoustic liner will be restricted in an aircraft especially in an unmanned aerial vehicle. Piezoelectric materials form an array, thus forming a disturbed impedance adjustable acoustic liner system. A direct current within 30 V is imported between upper electrodes and lower electrodes, thus enabling the acoustic liner to work in a static mode. An alternate current of 30V is imported, thus enabling the acoustic liner to work in a dynamic mode. In two modes of the static mode and the dynamic mode, the relatively high acoustic absorptivity is kept in the broadband. A device realizes synchronous adjustment of acoustic impedance and two working modes. The system complexity is reduced to the greatest extent; system integration and miniaturization is convenient; and the band range of the acoustic liner is extended.

Description

technical field [0001] The invention belongs to the technical field of noise control, and in particular relates to an acoustic lining and a control method for dual-working modes for broadband noise suppression. Background technique [0002] Broadband acoustic lining and controllable acoustic lining technology are research hotspots in academia and engineering circles. With the continuous advancement of science and technology, new acoustic linings continue to emerge. Impedance-adjustable acoustic lining is a combination of active and passive control of noise, taking advantage of their respective advantages to selectively suppress noise. [0003] The acoustic lining processed by the traditional process generally has a micro-perforated honeycomb structure, which is designed for a specific noise source. Once the design and processing are completed, it only has a good sound absorption and noise reduction effect on the noise source of a certain frequency. Once the frequency of the...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H04R3/00
CPCH04R3/00
Inventor 吕海峰赵心远张青青安君陈鹏
Owner ZHONGBEI UNIV
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