Reasearch On Noise Control Of Compound Perforated Tube Muffer

Effective,stable and continuo us absorption and reduction of broadband and high-complex spectrum noise are important factors to improve vehicle driving comfort.The structure of the porous tube muffler effectivel y s uppresses high-frequency noise,while the membrane structure inhibits low-frequency noise.Combined with FEA and experiment,a porous tube muffler with a composite structure is proposed.The main research of this article is as follows:Firstl y,based on Python’s multiple linear regression algorithm and resonance absorption ef fect,modular series and parallel porous tube mufflers are designed.So as to avoid the s ystem resonance caused by pipeline vibration,Workbench software is used to anal yze the modal response of the structure when the three phases of non-flow state,heat flow state and solid state are combined at room temperature.Acoustic simulation shows that the muffler has a transmission loss greater than 20 d B in the frequency range of 470 to 4500 Hz,which could effectively suppress mid-high frequency noise.The porous tube structure and flexible membrane composite porous tube muffler have been designed to suppress the complex low frequency spectrum noise in the tube.COMSOL’s acoustic coupling anal ysis varify that transmission loss which is in the frequency range of 40 to 941 Hz,reaches 20 d B.The stronger the coupling between the sound wave and the membrane resonance s ystem,the stronger the vibration response of the membrane,and the less sound energy is transmitted to the downstream pipe.The peak frequency of the trans mission loss is be consistent with the natural frequency of the film.The film vibrates the most.Simulation and experiments varify that the attenuation frequency of the noise could be adjusted by the sound motion of the flexible film.Piezoelectric silencers with perforated tubular structures with piezoelectric membranes have been designed to allow adaptive noise control.The results show that the piezoelectric plate based on the reverse action of piezoelectric material can effectively suppress or enhance the vibration response of the film and transform the vibration resistance point.Driving voltage changes from 0 to300 V,the first peak fre quency of squelch changes from 9 5Hz at high frequency,and the second peak frequency changes from 1 35 Hz at high freq uency.When the frequency of the noise changes,the driving voltage can be adjusted to control the noise of several low frequency bands,the low frequency compound spectral noise is reduced.