Experimental Investigation on the Effect of Shell Design on Noise Quality and Performance of an Automotive Exhaust Muffler

This research paper is dealing with development of a Hybrid Exhaust muffler with four different shell configurations (Internal design unaltered) and investigated the impact on noise performance and quality (perceived). Noise performance has been evaluated by measurement of Pass by Noise and near exhaust noise Level on a typical 16T -6-speeds transmission Truck. The experimental activity conducted based on DOE approach. From this study, it observed single shell with lower thickness have the poor NVH performance and perceived quality as well. Shell or booming noise is also observed with this configuration. Double shell with Ceramic blanket (throughout the length) sandwich configuration exhibited the best performance though this design is most expensive among the four mufflers. Remaining two Configurations (i.e. - Single shell of higher thickness and Double shell with Ceramic blanket only around reactive chamber) displayed at per results in both perceived noise quality and Noise performance. There are difference around 0.6 dBA noise at 3^rd and 4^th Gear Pass by Noise (PBN) level among best and poor performing Shell configuration muffler. The experimental research has revealed the importance of Shell Configuration/Design on acoustic/NVH performance and Noise (perceived) Quality of muffler as well at Vehicle Level.