Research On Distribution Of The Internal Combustion Engine Noise And Reduction Technology

Since the internal combustion engine has good dynamic,economy,environmental protection and reliability,has been widely used in various fields of production and life,it can be said that the internal combustion engine played a significant role in the national economy and the development of science and technology.Therefore,in the future for a long period of time,internal combustion engine will occupy the important position as a mainstream machinery in the field of transportation and engineering machinery.With the development of the internal combustion engine to a high speed,high power,high efficiency direction,noise and vibration problems will be more prominent,and is directly related to the life of the machine,working efficiency,operational safety and environmental pollution.Therefore,understand the distribution of noise and vibration and study the noise and vibration of internal combustion engine,put forward reasonable noise reduction measures according to the distribution of noise and vibration and spectrum characteristics,for the control of noise and vibration of internal combustion engine has important practical significance and application value.In this paper,based on noise and vibration of internal combustion engine,test of a diesel engine noise and vibration using the noise and vibration test and analysis system.Using Artemis software for analysis,obtain the spectral characteristics and distribution of the diesel engine noise and vibration.Informed by diesel engine spectrum characteristic analysis,the noise sound pressure level near air inlet of diesel engine is the largest,as the main noise source.So,the noise reduction measures considering design good intake muffler.Analysis the air intake noise spectrum,known in the frequency of 315 Hz and 630 Hz noise contribution amount is larger.Therefore,focus of considering the elimination of the center frequency of 315Hz and 630Hz when designing muffler,and can better eliminate the high frequency noise,calculated to determine the muffler design scheme.For the muffler designed using comsol software simulation calculation of transmission loss,Analysis of simulation results,according to the simulation results further optimize of the muffler structure,determine the final design scheme after optimization.In order to examine the actual silencing effect,using B&K 4206-T impedance tube test the transmission loss of muffler,get muffler transmission loss curve,comparative Analysis the transmission loss of simulation and test,over the entire frequency range of the test and simulation transmission loss curve basically the same trend,in the low frequency simulation calculation results are in good agreement with test results.