INFLUENCE OF TWO ROUND IMPEDANCE NOISE PROTECTION SCREENS ON THEIR EFFICIENCY

Abstract

The acoustic field of the traffic flow around the noise barriers located on both sides of the sound source has been investigated. The overwhelming number of publications devoted to the topic of noise protection with noise barriers concerns the assessment of the effectiveness of screens located on one side of the noise source. Investigation of the influence of the second screen on the efficiency of the first one, if it was investigated, then only by experimental research. In this work, a theoretical study of the mutual influence of two impedance screens, between which a linear sound source is located, is carried out. The problem is formulated in such a way that it made it possible to apply the method of partial regions for the analytical solution of the problem of finding the sound field around a linear sound source. In this case, the sound source is limited on both sides by impedance screens of appropriate thickness. By their shape, the screens are part of a circle with arbitrary corners and the same radius. When solving the problem, an infinite algebraic system of equations is obtained, which is solved by the reduction method. The results of such studies allow assessing the field both between screens and behind screens. This will make it possible to determine the effect of impedance surfaces simulating partial sound transparency on the acoustic field around such screens. This will allow assessing the effect of soundproofing screens on their effectiveness. Such studies will make it possible to more accurately calculate the sound field levels of traffic flows when using impedance noise barriers. It will also make it possible to reasonably put forward requirements for the minimum oundproofing capacity of the screen structure.