Numerical Analysis of Silencers Composed of Screw Tube, Expansion Cone, Orifice Plate, and Perforated Tube by Finite Element Method

As the noise of engines in factories results in hearing damage, it is mandatory to install silencers.Traditional noise abatement practices involve using one silencer for each venting noise source, leading to cost increase issues when multiple intermittent venting noises are present.Thus, the need for a smart system capable of switching the venting duct to a specific silencer becomes crucial.To address this need, a smart duct switching system is proposed, integrating electric valves, microphones, a controller, and a single silencer.To enhance noise reduction, various types of silencers are examined to investigate their performance in noise reduction.A finite element method (FEM) was adopted to simulate and evaluate the degree of noise reduction.The transmission loss (TL) of silencers with screw tubes (silencer A), expansion cones (silencer B), orifice plates (silencer C), and perforated tubes (silencer D) was evaluated by simulation with COMSOL software.The results indicated that screws did not reduce noise effectively even when combined with expansion cones, orifice plates, and perforated tubes.However, expansion cones, orifice plates, and perforated tubes effectively decreased noise, and their performance was higher when used without screws.Among the various devices, perforated tubes reduced noise most significantly.