Performance of Absorptive Material Liners on Noise Transmission Loss in Mufflers used by Goods Carrying Tricycles

Due to the increase in the number of goods carrying tricycles, the amount of noise and pollution on our roads has increased. Different absorptive material liners have been introduced into muffler design to optimize the control of the engine noise emission for tricycles. In this study, the performance of Aerogel, Ceramic, Kenaf fibre, Polyester and Rockwool as absorptive material liners on the transmission loss under 20 ℃, 60 ℃, 100 ℃, 150 ℃ and 200 ℃ temperature treatment for goods carrying tricycle was evaluated. The analysis averaged over all temperature treatments showed that introducing absorptive materials into the muffler improved the performance by 71.56 %, 84.12 %, 86.31 %, 89.37 % and 93.99 % for Aerogel, Rockwool, Ceramic, Polyester and Kenaf fibre respectively. Similarly, analysis averaged over all absorptive material treatments disclosed that the muffler with an absorptive material liner under 60 ℃, 100 ℃, 150 ℃ and 200 ℃ temperature treatment improved the performance over the muffler without a liner by 85.1 %, 80.8 %, 87.5 % and 92.3 % respectively. The flow resistivity values for the absorptive material liners used were inversely proportional to the transmission loss except for the Kenaf fibre which had the highest transmission loss though with the second highest flow resistivity. PLSR analysis showed that Aerogel, Rockwool, Ceramic, Polyester and Kenaf fibre yielded better prediction accuracy than the No liner by 33.88%, 32.75%, 30.45%, 30.41% and 22.35% respectively. The study has confirmed that introducing absorptive material liners in mufflers used by goods carrying tricycles can optimize performance.