| Noise is one of the main pollution in the modern city which also can be the important index for automotive environmental performance evaluation.So with the rapid development of automobile industry,the annual growth rate of vehicles is higher and higher.People require more on the comfort and vehicle noise control.According to relevant data which shows 70%of the noise came from the traffic in cities which point to the vehicle noise.Therefore,on the one hand,both domestic and overseas are more striction the vehicle noise regulations and lowest noise limit.Car manufacturer at home and abroad,on the other hand,are more delicate in research and development on reducing the noise of air intake system.Based on the detailed parameters of the one-dimensional pipeline acoustics theory and principles of silencing the original model,through order time analysis and mode analysis,aiming at one domestic model,the digital-analog of air intake system pipeline drew by CATIA software is processed by Hyper Mesh and GEM3D software Then through LMS virtual lab and GT-power modal analysis and order analysis on the d/a respectively,thus simulation analysis of air intake system is finished through the method of CAE.Then,the simulation results’ effectiveness is confirmed by the comparison with the noise date tested by the LMS test lab.In addition,the further analysis with the simulation software on the basis of the original inlet into the tube,the improvement the length of the inlet into the pipe reduces the noise level of the 6,8,meanwhile increases Helmholtz cavity and eliminates the resonance zone of 230 Hz.Eventually the noise of the whole air intake system full order and each order conform to the requirements of the noise limitation. |
