Research On Noise Reduction Technology Of Smart Acoustic Structures

Noise has great harm both in industry and transportation as well as in national defense and military fields.It is urgent to reduce and further resolve such noise hazards.Acoustic liner is one of the most effective means to control noise and is widely used in noise control research.At the same time,with the development of new piezoelectric smart materials and control technology,noise control based on acoustic liner structure combined with piezoelectric smart material has been achieved and many research results show strong research potential.Firstly,the acoustic finite element model of sound-absorbing structure was created with UG software.Acoustic simulation was calculated by Virtual.Lab and COMSOL software.At the same time,two different structural design methods were introduced.The simulation results were analyzed and imported into MATLAB software to obtain the transmission loss.Curve,combined with its simulation characteristics to optimize the sound-absorbing structure.Secondly,taking the smart sound-absorbing structure as the experimental object,the distributed piezoelectric vibrator is embedded on the surface of the structure as an actuator.Using LabVIEW software,a control system that uses the noise real-time frequency as a criterion and collects and modulates data is developed.An experimental system for automatic collection and processing of smart sound absorption structure data.Furthermore,on the basis of completing the development of the smart sound-absorbing structure noise reduction control system,an experimental platform for noise reduction performance testing is set up,experimental verification and analysis of the designed smart sound-absorbing structure and program are performed,and the smart sound-absorbing structure is tested to meet reality.Under the conditions of application,the critical gradient of the cavity height is 3.6mm,the critical value of acoustic liner quantity is 7 basic units and the maximum audible frequency range that can be achieved is 350 Hz to 1045 Hz.Finally,pressurization experiments were performed on the structure of the achievable maximum noise cancellation frequency range to achieve a 34 Hz offset of the resonance frequency of the sound-absorbing structure within a voltage of 500 V.The research results show that the designed sound-absorbing structure and experimental test achieve that when the noise frequency changes,the smart sound-absorbing module can automatically adjust the drive voltage to achieve the variable-frequency noise control,effectively broadening the sound-absorbing structure's silencer frequency range.In order to make up for the shortcomings of traditional sound-absorbing structures,the effective noise reduction band is too narrow.In this paper,acoustic liner structures and piezoelectric smart materials are used to design sound-absorbing structures with multiple sizes and adjustable volume of resonant cavities.This structure can effectively broaden the range of noise reduction bands.To achieve the shift of the transmission loss peak,it has changed the disadvantages of the traditional acoustic liner structure with a single parameter and the specific noise elimination frequency.