Noise reduction by a barrier in the form of a solid plate grid

Abstract

Ventilated Soundproofing Structures are widely used today to protect buildings and adjacent areas from noise generated by industrial equipment that requires air supply for normal operation. Designers pay considerable attention to the development of ventilated noise barriers, even though standardized or reference methods for calculating their acoustic performance are virtually nonexistent. In this context, research on louver-type screens, which provide both noise reduction and airflow, is highly relevant. A specific case of a louvered screen is a grille with parallel slits—this article focuses on the calculation of sound transmission through such a structure. The noise reduction provided by a screen consisting of thin plates spaced at equal intervals is calculated using the finite element method. This paper describes the numerical experiment setup, introduces a parameter characterizing the noise reduction efficiency of the screen, and presents the calculated results of this parameter depending on the grille’s geometric dimensions and sound frequency.

 It is shown that the screen’s efficiency is determined by the ratio between the plate width and the gap between them: the smaller this ratio, the higher the efficiency. The study identifies grille parameters that ensure noise reduction of at least 10 dB. The results can be directly applied to the design of soundproof ventilation grilles and ventilated noise barriers.