Investigation of the Geometrical Parameters Effects of Reactive Muffler on Noise Reduction by Considering the Pressure Drop

In this paper, the influences of the geometrical parameters of reactive muffler on acoustic attenuation performance and pressure drop have been investigated by using FEM. These effects consist of: to extend the inlet tube into the expansion chamber and increasing its length, adding holes to the extension and changing their number and position. The equations have been solved along with damped Newton method. The k-ε turbulent model was used for flow field analysis. The results show that the acoustic attenuation performance improves and the pressure drop decreases by extending the inlet tube and increasing its length. Moreover adding holes to extension, increasing their number and setting the holes near the end of expansion chamber increase the maximum attenuation frequency without considerable change of the pressure drop. So they can be used to improve the design of muffler at target frequency range.