A study on exhaust muffler with low backpressure

Conventional muffler of internal combustion engine is mostly constructed as a mixture or combination of perforated ducts, baffle or perforated baffle, expansion chamber, etc., the noise reduction is limited and backpressure is high hence the fuel efficiency is low. In this paper, a new concept of exhaust muffler is proposed. Its principle is proved by the numerical simulation and its superior performance for noise reduction as well as lower backpressure is qualitatively confirmed by the experiments conducted on the S1115 single cylinder diesel engine. The result shows the new muffler´s good transmission loss characteristic in the wide range of engine speed and lower backpressure comparable to the original passive muffler.