LAUSR

The paper presents the results of a computational–experimental study of jet noise reduction using the screening effect. According to correlation theory, the noise sources of a single circular jet are represented by a set of uncorrelated quadrupoles. Using the basic relations of geometric diffraction theory (GDT), expressions are obtained for the sound field emitted by a point quadrupole source located near an acoustically rigid infinite half-plane. Using the expressions obtained in the framework of the GDT, the correlation model of the jet noise sources was adapted to the calculation of the sound field in the presence of a flat rectangular screen. A comparison of the calculated and experimentally measured spectra of sound pressure levels, performed at a given jet velocity and various screen positions, showed good qualitative, and for certain observation angles, quantitative agreement.