Characterization and Improvement of Two-Wheeler Exhaust System Component Using Vibro-Acoustic Technique 2021-26-0276

Exhaust system is a key component defining the noise character of any two-wheeler. With increased demand by customers for vehicle refinement, exhaust system has to face the challenge of imparting noise character to the vehicle and be refined at the same time. Apart from noise character of the vehicle, homologation requirement is also an important factor from exhaust system performance point of view especially with new and stringent norms being introduced. Exhaust mufflers play an important role in performance of exhaust system and hence muffler characterization is always done in detail as per standard practices. However, it is equally important to consider entire exhaust system for performance study. This paper deals with identification of an irritant noise perceived from two-wheeler. The source of this noise character was exhaust system component of the vehicle other than muffler. Further, characterization of exhaust system component using vibro-acoustic technique was done in order to study and mitigate the irritant noise character of vehicle. The study involved mapping of noise character of exhaust system along with surface vibration measurement. Further to operational condition measurements, frequency response function was studied to identify the issue. Based on the findings of the vibro-acoustic study, suitable modifications in the exhaust system components were made to address the irritant noise character. FRF measurement of modified component indicated significant improvement in area on concern. With confidence of FRF result on modified component, operational measurement on vehicle was conducted to confirm the improvement in noise character of vehicle.

This study establishes a methodology for characterization of exhaust system components using vibro-acoustic approach and highlights the importance of each component of exhaust system in overall noise character of vehicle.