Expert: Paul Soderman - 1/24/2005

Question
Sir,
1)can you highlight some basic fundamentals involved in muffler design?
2) can you suggest some relevant and useful reading for a beginner like me?
thanks

Answer
Srivatsan

There are many type of mufflers depending on the noise problem to solve. For common engine exhausts, passive mufflers have fiberglass wrapped porous ducts that the exhaust must pass through. Length of duct is critical. Reactive mufflers have side branches, area changes and convoluted passage ways designed to reflect the fundamental tones of the engine. Simple air ducts often are silenced with treated baffles that have porous screens over sound absorbant material.   I suggest you find a good noise control book such as L. Beranek and I. Ver:  Noise and Vibration Control Engineering (John Wiley and Sons 1992).  Another is Acoustics of Ducts and Mufflers by M. Munjal (John Wiley and sons, 1987), though it is somewhat mathematical in nature. There are other muffler design books with more empirical examples such as the Engineering Noise Control, Theory and Practice by D. Biese and C. Hanson, one of my favorite books.

Good luck.

Paul