Amirkabir University of Technology Amirkabir Journal of Mechanical Engineering 2008-6032 56 3 2024 05 21 Experimental and numerical investigation of transmission loss in a zero-flow silencer Experimental and numerical investigation of transmission loss in a zero-flow silencer 411 438 5490 10.22060/mej.2024.22981.7704 FA Hossein Moein Department of Mechanical Engineering , Ferdowsi University of Mashhad, Mashhad, Iran Mohammad Passandideh Fard Department of Mechanical Engineering, Ferdowsi University of Mashhad, Mashhad, Iran Ali Faezian Department of Food Machinery Design, Research Institute of Food Science. Mashhad. Iran Journal Article 2024 02 07 To evaluate the acoustic performance of the muffler at zero flow, different methods of determining transmission loss (TL) were studied. Numerical and experimental approaches were used to calculate TL. The numerical method employed was the Herschel-Quincke tube method (case 1) COMSOL simulation (case 2) and ANSYS simulation (case 3). The experimental approach utilized the transfer matrix method with the aid of software developed by the B&K software (case 4) and the sound card with MATLAB software (case 5) was used to calculate TL. Furthermore, the mesh independence of numerical methods and the uncertainty of the experimental method were examined. Results were evaluated between 20 and 1900 Hz, which is an appropriate frequency range for TL calculations. According to the results, the equivalent TL for cases 1 to 5 is approximately 5.81 dB, 5.35 dB, 5.21 dB, 4.08 dB, and 3.77 dB, respectively. Based on the findings, it can be concluded that the equivalent TL of ANSYS and COMSOL simulations was similar, and COMSOL simulation results in an 8% lower equivalent TL than the case 1 approach. Similarly, the equivalent TL of experimental calculation methods indicates that the case 5 approach has a 7.5% lower equivalent TL than the case 4 approach. To evaluate the acoustic performance of the muffler at zero flow, different methods of determining transmission loss (TL) were studied. Numerical and experimental approaches were used to calculate TL. The numerical method employed was the Herschel-Quincke tube method (case 1) COMSOL simulation (case 2) and ANSYS simulation (case 3). The experimental approach utilized the transfer matrix method with the aid of software developed by the B&K software (case 4) and the sound card with MATLAB software (case 5) was used to calculate TL. Furthermore, the mesh independence of numerical methods and the uncertainty of the experimental method were examined. Results were evaluated between 20 and 1900 Hz, which is an appropriate frequency range for TL calculations. According to the results, the equivalent TL for cases 1 to 5 is approximately 5.81 dB, 5.35 dB, 5.21 dB, 4.08 dB, and 3.77 dB, respectively. Based on the findings, it can be concluded that the equivalent TL of ANSYS and COMSOL simulations was similar, and COMSOL simulation results in an 8% lower equivalent TL than the case 1 approach. Similarly, the equivalent TL of experimental calculation methods indicates that the case 5 approach has a 7.5% lower equivalent TL than the case 4 approach. https://mej.aut.ac.ir/article_5490_c900ced7451da79502d29aa37ebb7b60.pdf