An Approach to Reduce the Product Variants through Design of Hybrid Muffler for Commercial Vehicle Application 2013-26-0096
Exhaust noise of automobiles is one of the major sources of noise pollution. Un-muffled exhaust noise is quite higher than other noise sources of automobile. Therefore, the use of an exhaust muffler is prompted by the need of engine exhaust noise reduction. Insertion loss is the key metric to evaluate the performance of any muffler and it mainly depends upon proper selection of muffler volume which is proportional to engine swept volume. Another major performance evaluating metric is backpressure. Also, shape, size, weight, durability, manufacturability and cost are the secondary but important criteria of muffler selection. Presently, there are many variants of exhaust muffler, having different overall performances (i.e. insertion loss, backpressure, shape, size, weight, manufacturability and cost) used for different variants of commercial vehicle, though engine swept volume is same for all. In this context, authors have designed a new combination or hybrid type muffler where both reactive and absorptive noise attenuating principles are used in single unit. Afterward, performances of this new muffler are evaluated experimentally in comparison to best existing muffler through measurement of noise level and backpressure of exhaust system. Also, comparative study is done for this muffler for verification of secondary performance criteria. The primary objective of this work is to reduce the product variants of muffler which are applicable for same swept volume by designing a high performing muffler. Another objective of the present work is to study the effect of major design parameters on both performances as well as selection criteria of muffler. Further, it is possible to develop high performing muffler without any assistance of latest analysis software and experimental technique.