Modeling the Aerodynamic and Acoustic Characteristics of Plate Dissipative Silencers

Abstract

The acoustic and aerodynamic properties of dissipative silencers with plates of constant and variable shape are compared. The purpose of the study was to jointly consider the aerodynamic and acoustic characteristics of silencers of various shapes. The effect the sound-absorbing material density has on the noise attenuation in the silencer is considered. It is shown that the use of variable-shape plates makes it possible to reduce the silencer flow friction. This results in a lower energy consumption for driving the fans and exhaust pumps and in a lower influence of flow friction on the technological processes at power and other industrial enterprises. It is shown that in the case of using plates with a constant shape, a drop in static pressure occurs in the channel between them, whereas in the case of using plates with a variable cross-section, the static pressure increases. With a free area ratio of 38%, the flow friction is reduced by up to 79%. The dependence of noise attenuation in the channels of plates with variable cross-section and constant shape on the free area ratio has been determined. In designing the silencer structures for noise reduction, it is recommended to use silencers with plates of variable cross-section, which have a significantly lower flow friction with the same acoustic efficiency in comparison with plates of a constant shape.