| The oxygen generator on the plateau special vehicle can effectively improve the air quality in the car and reduce driving fatigue,but with the improvement of technology,the noise of the traditional automobile engine has been greatly reduced,and the impact of the oxygen generator noise on the driver is more and more obvious.The noise of oxygen generator is divided into two parts,one part is the noise transmitted to the outside of the compressor,the other part is the vibration noise of the oxygen generator shell.Compressor is the key component and noise source of oxygen generator.Its kinematic performance and vibration and noise will have important influence on oxygen generator.In this paper,the dynamic time-domain curve of each component of the compressor is obtained by establishing the dynamic model of the compressor drive system.Meanwhile,the vibration characteristics of the compressor shell surface are analyzed by using the modal superposition method to obtain the vibration displacement of the compressor shell surface.Moreover,the radiation noise of the compressor is analyzed based on the direct vibration response,and the sound field and pressure nephogram and response curve of the compressor are obtained.Carry out compressor noise experiment test to ensure the correctness of simulation method;By establishing the acoustic finite element model and structural finite element model of oxygen generator,taking the compressor radiation noise and the dynamic excitation of oxygen generator as the boundary conditions,the modal based acoustic and vibration coupling radiation noise analysis of oxygen generator is carried out,and the sound pressure amplitude generated by oxygen generator at multiple frequency points is found.The radiation noise,directivity,modal participation factor and acoustic plate contribution of oxygen generator are analyzed.It is found that the peak noise of some frequency points of oxygen generator is larger.The shell structure of the oxygen generator is optimized based on the theory of two-dimensional acoustic black hole,and the influence of the acoustic black hole structure size,power index,laying radius of the damping layer and laying thickness on the vibration characteristics is analyzed to complete the vibration and noise reduction of the oxygen generator.The results show that the vibration response and radiation noise of the compressor affect the trend of the sound pressure level curve of the oxygen generator.The peak of the sound pressure of the oxygen generator is mainly affected by its own structural properties.After optimization,the sound pressure amplitude-frequency curve of each node of the oxygen generator is reduced in different degrees. |
