Investigation of the Combined Effect of Perforated Tube, Baffles, and Porous Material on Acoustic Attenuation Performance

In this work, muffler with perforated baffles and pipes has been studied for noise attenuation characteristics. Transmission loss parameter is used to quantify the acoustic performance in the muffler. The purpose of our study is to find the optimum arrangement for getting the best optimized effects for absorptive material on porosity of baffle plates and length of perforation in the pipes. The computational acoustic simulation tool COMSOL Multiphysics is used for modeling transmission and predicting acoustics absorption behavior through the porous pipe of the muffler. In the present study, two different configurations have been analyzed. Out of these, one configuration is structurally different in respect of the effect of porosity of the perforated pipes at inlet and outlet on the TL performance. Effect of porosity of the perforated pipe with absorptive material and the other configurations differs regarding the presence or absence of absorptive material in third chamber. The most important and significant outcomes of this study facilitate an optimum design of the muffler in 3D, which having optimum absorption for the exhaust gases induced noise generated in the muffler. It had been shown that perforated baffles play a crucial role in making the configuration of very robust. It was observed that 5% porosity is higher counterproductive in comparison with the other values of the porosity. The presented muffler is effective in attenuating the low–medium frequency as well as higher frequency band noise. The analyzing of the intake and exhaust lines of the muffler helps in reducing the vibrational losses.