DEVELOPMENT OF A COMPOSITE NOISE MUFFLER FOR SMALL GENERATING SETS

Sound proof generating sets are normally associated with higher power output and it is costly. This is not commonly found in small generating sets as there are often acquired by low income earners and yet they desire the some comfort. This research focuses on the development of a new composite muffler for small generating sets. The design combined the principles of reactive and active noise reduction approach. The newly designed muffler was compared with an existing design and its performance evaluated. Performance tests show an improvement in terms of insertion loss and transmission loss and a reduction in back pressure build-up in the generating set. The average overall efficiency of the existing muffler is 43.28% whereas that of the newly designed composite muffler is 55.83%.The designed composite muffler provides the gasoline generating set with an additional noise reduction (attenuation) of 17.33 dB, reduced back pressure build-up of 3.6 kPa and improvement of 12.09% overall engine efficiency.