Development of typical elements of silencers for internal combustion transport engines

BMSTU, Power Engineering Department, 105005, Moscow, Russia

^* Corresponding author: vvtupov@mail.ru

Abstract

Analysis of various methods for calculating acoustic efficiency of the transport engine noise silencers was carried out, their advantages and disadvantages were considered. Besides, it was shown that acoustic calculation methods, in particular the four-terminal method, could be used at the relatively small noise silencer structure elements cross-section and provide the acceptable accuracy. Analytical dependence for calculating the noise silencer acoustic efficiency using coefficients of its transfer matrix are provided. Conducted analysis of the transport engine noise silencer design made it possible to develop a number of typical noise-suppressing elements, using which allows to synthesize most of the reactive noise silencers for this purpose. On the example of a specific exhaust noise silencer, a method is shown for its representation in the form of a set of cascade-connected developed typical noise suppressing elements, each of them is described by a corresponding transfer matrix. Multiplying these matrices, the given noise silencer transfer matrix coefficients could be obtained. The resulting mathematical model of a noise silencer makes it possible to calculate its acoustic efficiency depending on its frequency and opens up a possibility to further optimize the noise silencer design using a computer. Standard elements versatility indicates possibility of their widespread use in calculating and designing various types of vehicle reactive noise silencers.