Study On Experimental Of Noise Absorption In Cabin

As we all know,noise pollution is one of the three major sources of pollution around the world.With the rapid development of human society,noise pollution is becoming more and more serious.A comfortable environment in daily life is very important to people.Therefore,the in-depth study of indoor noise reduction is becoming more and more important.In this paper,a new type of sound absorptive material is used to study the sound absorption and denoising methods of the cabin model.On the basis of learning a large amount of literature,firstly,this paper introduce the theory of indoor sound field and the sound absorption principle and characteristics of sound absorbing material.The finite element simulation software of ANSYS is used to simulate the sound field in the cabin model,the results show that the energy at the frequency of 1kHz in the sound field in the cabin is the most easily excited.At the same time,a variety of new sound-absorbing materials were tested by reverberation chamber.The polyimide material was screened out by comparative analysis.After that,the test system was built by two cabin models.The noise reduction experiment was carried out by using the chamber model.The single-frequency sinusoidal signal,the broadband white noise signal and the motor signal were used as different excitation sources to study the cabin sound field and the noise reduction effect of sound absorbing and damping material.Finally,the experimental data were processed and analyzed.The results show that the sound field in the cabin model has different characteristics when using different excitation sources.When the single-frequency sinusoidal signal is used as the excitation source,the degeneracy of normal mode of the cabin is serious and the sound field is not steady.When the motor signal is used as the excitation source,the sound field in the cabin is relatively steady,but the interference with the 50 Hz in the circuit is serious.When the broadband white noise is the excitation source,the cabin is approximately the ideal diffusion field.In this point,using a new damping material to the cabin model can get 19 dB noise reduction effect,useing sound-absorbing material can get 9dB noise reduction effect additional.