An acoustic enclosure system with both interior sound reduction and air ventilation is designed and demonstrated.The system consists of a rectangular enclosed space coupled with ventilated metamaterials and microperfo...An acoustic enclosure system with both interior sound reduction and air ventilation is designed and demonstrated.The system consists of a rectangular enclosed space coupled with ventilated metamaterials and microperforated panels(MPPs).By modeling the ventilated metamaterial as an impedance boundary condition,an analytic model is developed to characterize the frequency response of interior acoustic fields and evaluate the sound reduction performance of MPP structures.Numerical simulations are conducted to validate the accuracy of the theoretical model.It is found that the resonance response of the enclosure system can be suppressed by proper arrangement of the MPPs.Even with open area for airflow,the system still possesses good sound isolation originating from the low-transmission behavior of the ventilated metamaterial.The proposed model system may find potential applications in noise control engineering.展开更多
The numerical simulations and experimental results of an ultra-broadband acoustic ventilation barrier composed of periodic unit cells are reported in this paper.Based on multiple mechanisms,including sound absorption ...The numerical simulations and experimental results of an ultra-broadband acoustic ventilation barrier composed of periodic unit cells are reported in this paper.Based on multiple mechanisms,including sound absorption by eigenmodes of the unit cell and sound reflection by a plate structure on upper surface of the unit cell,a single-layer ventilation barrier with broadband sound reduction is designed,and its working bandwidth can reach about 1560 Hz.The experimental results accord well with the simulation results.Furthermore,two types of three-layer ventilation barriers are designed and demonstrated by using the unit cells with different values of a(the length of the hollow square region)and w(the width of the channel between the adjacent cavities),and the bandwidths of both ventilation barriers can increase to 3160 Hz and 3230 Hz,respectively.The designed barrier structures have the advantages of ultra-broadband sound reduction and ventilation,which paves the way to designing high-performance ventilation barriers for the applications in environmental protection and architectural acoustics.展开更多
Experimental results of sound transmission loss in a range of frequency through bubbly curtains were obtained, where the air content was in a wide range by means of varying pressure differences and the diameters of th...Experimental results of sound transmission loss in a range of frequency through bubbly curtains were obtained, where the air content was in a wide range by means of varying pressure differences and the diameters of the pores of bubble-produce apparatus . Vibration reduction of a vessel in water due to the bubbly curtain was found.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.12225203,11622215,and 11872111)the 111 Project(Grant No.B16003).
文摘An acoustic enclosure system with both interior sound reduction and air ventilation is designed and demonstrated.The system consists of a rectangular enclosed space coupled with ventilated metamaterials and microperforated panels(MPPs).By modeling the ventilated metamaterial as an impedance boundary condition,an analytic model is developed to characterize the frequency response of interior acoustic fields and evaluate the sound reduction performance of MPP structures.Numerical simulations are conducted to validate the accuracy of the theoretical model.It is found that the resonance response of the enclosure system can be suppressed by proper arrangement of the MPPs.Even with open area for airflow,the system still possesses good sound isolation originating from the low-transmission behavior of the ventilated metamaterial.The proposed model system may find potential applications in noise control engineering.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.12174159,12274183,and 51976079)the National Key Research and Development Program of China (Grant No.2020YFC1512403)the Research Project of State Key Laboratory of Mechanical System and Vibration (Grant No.MSV202201)。
文摘The numerical simulations and experimental results of an ultra-broadband acoustic ventilation barrier composed of periodic unit cells are reported in this paper.Based on multiple mechanisms,including sound absorption by eigenmodes of the unit cell and sound reflection by a plate structure on upper surface of the unit cell,a single-layer ventilation barrier with broadband sound reduction is designed,and its working bandwidth can reach about 1560 Hz.The experimental results accord well with the simulation results.Furthermore,two types of three-layer ventilation barriers are designed and demonstrated by using the unit cells with different values of a(the length of the hollow square region)and w(the width of the channel between the adjacent cavities),and the bandwidths of both ventilation barriers can increase to 3160 Hz and 3230 Hz,respectively.The designed barrier structures have the advantages of ultra-broadband sound reduction and ventilation,which paves the way to designing high-performance ventilation barriers for the applications in environmental protection and architectural acoustics.
基金The project is supported by National Natural Science Foundation of China and Nationalshipbuilding Corporation
文摘Experimental results of sound transmission loss in a range of frequency through bubbly curtains were obtained, where the air content was in a wide range by means of varying pressure differences and the diameters of the pores of bubble-produce apparatus . Vibration reduction of a vessel in water due to the bubbly curtain was found.
