Calculation of Flow Field of Diffused Pneumatic Silencer

Diffused pneumatic silencer has been widely used in pneumatic fields because of its small dimensions and high performance on noise reduction. Numerical simulation of its interior and exterior flow field is important to studying the gas flow in the silencer and the flow structure outside the silencer, understanding the mechanism of its noise reduction. Porous media model and Darcy-Forchheimer principle are used as the basic theoretical frame in this paper. The unified governing equations are used to describe the compressible flow in and out of the silencer. Robust numerical scheme is used to discritize the equations and the TDBC(Time-dependent boundary conditions) is used to treat the non-reflect boundaries. The detailed structures of the inner and outer flow field of the diffused pneumatic silencer are gotten. The results of the simulation display the characteristics of the flow in the silencer. And the structure of the flow outside the silencer that can be compared with the experimental data is gotten.