Numerical Modeling and Geometry Enhancement of a Reactive Silencer

Internal combustion engines and blowers frequently utilize silencers to reduce exhaust noise. In the current paper, transmission loss of reactive is predicted using plane wave decomposition method a three-dimensional (3-D) time-domain computational fluid dynamics (CFD) approach. A mass-flow-inlet boundary condition first used perform steady flow computation, which serves as an initial for two subsequent unsteady computations. At model's inlet, impulse (acoustic excitation) placed over constant mass unstable computation. Once has fully propagated into silencer, non-reflecting (NRBC) then added. For scenario without acoustic excitation at second computation performed. During transient computations, time histories pressure velocity upstream measuring points well history pressures downstream point are recorded. The related quantities show variations between findings. As result, transmitted sound signal just downstream, while incident obtained by utilizing upstream. (TL) silencer calculated after Fast Fourier Transform (FFT) converts signals from domain frequency domain. numerical calculations reported data in good agreement published results, addition geometry enhancement increasing number holes cross section muffler.