Pressure Loss in Ducts by Dissipative Splitter Silencers: Comparative Study of Standardized, Numerical and Experimental Results

Bartosz Chmielewski,Paweł Nieradka,Iván Herrero-Durá

doi:10.3390/app112210998

Abstract

Dissipative splitter silencers are widely used in industry for the reduction of propagated sound waves in ducts. Even though these systems are effective from the acoustics point of view when they are properly designed, they also introduce a pressure loss in the system, due to the modification of the properties of the flow circulating inside the duct. This effect is not desired in some industrial applications, so it is necessary to be able to predict the pressure loss as precisely as possible to design silencers according to the needs. Nevertheless, the prediction made by standards are usually limited to given geometries or flow speed. In this work, we present a comparative study on the results obtained for the pressure loss by means of the standards ISO 14163 and VDI 1801-1, numerical simulations with the finite element method, and experimental measurements. Additionally, two different profile shapes and four input face velocities are tested in order to know the influence of these parameters in the variations of the flow and the accuracy of the prediction of the different methods.

Highlights

Dissipative splitter silencers are the most used mechanical dissipative silencers in industry [1]
The results obtained by using the four methods described above (ISO, VDI, finite element method (FEM) and experimental measurements) are shown in Tables 3 and 4, in which it is possible to see at a glance the differences in the values of the pressure loss induced by the two types of profiles
This work presents a comparative study on the prediction of the pressure loss in a system composed of two dissipative splitter silencers embedded in a duct by using standards (ISO 14163 and VDI 2081-1), numerical simulations (FEM) and experimental measurements

Summary

Introduction

Dissipative splitter silencers are the most used mechanical dissipative silencers in industry [1]. Dissipative splitter silencers usually consist of a bulk reacting porous material with a given cross section and a perforated plate that protects this material from the conditions in the duct in which a low Mach number flow circulates [12]. This configuration provides them with good performance and effectiveness in the reduction of the propagated sound waves in ducts and, at the same time, simplifies their design and reduces the manufacturing costs. In those cases in which the flow is circulating through the duct, this leads to the modification of the local behavior of the duct in the vicinity of the silencers

Objectives

Methods

Results

Conclusion