| Enclosed space noise is an important influence in people's production and lives, many space are subject to noise interference, such as indoor, vehicle interior, cabin space and so on, in which have the most low-frequency noise, and it is also the most difficult to control. ANC technology has obvious advantages for the control of low-frequency noise. In recent years, people have done a great deal of studies on ANC, now application has been achieved in one-dimensional noise elimination, but progress in three-dimensional noise elimination is relatively slow, enclosed space ANC has become the difficult and hot issue on noise control.This paper detailed discusses the basic principle and mechanism on ANC of enclosed space, and then choosing a rectangular interior space as the sound field prototype, giving analysis and research for enclosed space ANC through simulation and experiment. In simulation part, COMSOL Multiphysics software is introduced to establish the geometric model of sound field, the range of research frequency sets as 50-400Hz. A key of ANC is the setting of dominant excited frequency, in the study, firstly getting the dominant excited frequency of objective space by feature pattern analysis and excited acoustic modal analysis, and then giving solving and analysis to the ANC condition of the entire low-frequency noise field by harmonic analysis of sound pressure, in order to optimize the number and layout of secondary noise sources. Simulative results have been verified by measuring the actual distribution in the prototype sound field.Conclusions of simulation and experiment as follows: through setting a reasonable number and layout of secondary sound sources, the objective can be achieved to make the sound pressure of any local area in sound space down to around 60dB; in the range of 50-400Hz, the larger of excited frequency, the more complex influence, the worse of the simulation , the more difficult of the noise elimination.
|
PDF Full Text Request