Optimization Design Of Muffler Structure Based On Genetic Algorithm

In recent years,the state has paid more and more attention to the environmental pollution,and the noise can not be ignored in the environmental treatment.Therefore,the relevant laws and regulations have been issued.The noise problem of commercial vehicles has become the current research hotspot.The use of muffler is the most effective way to reduce the noise in the vehicle intake and exhaust system.However,due to the limited installation location,the muffler is often unable to achieve the ideal Noise reduction effect.In this paper,genetic algorithm is introduced into the structure design of muffler.In the limited space,genetic algorithm is used to optimize the structure of muffler,and the method of combining software simulation and experimental verification is used to verify and analyze the optimal structure of muffler.The main research contents are as follows:First of all,the working principle and acoustic evaluation index of various silencers are studied.The one-dimensional model of silencers is analyzed by acoustic four terminal network method,and the general formula of theoretical calculation of transmission loss in silencing system is obtained.The mathematical models of expansion cavity silencers,inner tube silencers and Helmholtz silencers are established respectively,and the transmission loss is selected as the evaluation through comparative analysis Acoustic performance index of price muffler.Secondly,based on the study of the basic idea,characteristics and process of genetic algorithm,an improved genetic algorithm based on the combination of real coding gray code and the optimal saving strategy is proposed,which speeds up the convergence speed of the algorithm at runtime and improves the calculation performance.However,in the process of structural design of muffler,the constraint problem is involved,so penalty function is used to deal with the constraint.Then,on the basis of determining the design variables,constraints and objective functions,the optimization algorithm is applied to the muffler structure design.Through the simulation of the obtained muffler structure,the results show that the transmission loss peaks of the three kinds of mufflers are significantly increased,and the noise frequency can be reduced in a larger range.Furthermore,the muffler obtained by using the algorithm is further illustrated It can effectively suppress the propagation of noise.According to the two load measurement principle,the transmission loss test platform is built,and the acoustic performance of the designed muffler is tested.The test results show that: after optimization,the transmission loss peak value of the expansion cavity muffler increases to four,and the maximum peak value is 19.84 db.After optimization,the peak value of the internal intubation muffler increases twice,and the maximum transmission loss changes to 48.7db,Helmholtz After optimization,the transmission loss of the muffler increases to 13.9db.Through the comparison of the performance,we can know that the performance of the optimized muffler is further strengthened.Finally,the proposed optimization algorithm is applied to the engineering practice,and a muffler is designed for a Dongfeng truck to solve the noise problem of the air compressor during operation.The test results show that the designed muffler can suppress the air flow noise produced by the air compressor during operation and achieve good noise reduction effect.