REFRACTION MODELING OF SOUND EXPANSION IN THE OPEN AIR
Journal Title: Вісник Кременчуцького національного університету імені Михайла Остроградського - Year 2017, Vol 1, Issue 104
Abstract
Purpose. To model the sound waves trajectories propagation with one or several points of reflection provided refraction for the improvement of the general model for calculating aircraft noise levels near the airport. Methodology. The wave extensions radiation theory, the heuristic modification of sound ray tracing model, the general model of the aircraft noise propagation with allowance for the refraction effect have been used. Results. It has been established, that in the methodology for calculating the aircraft noise contours were not take into account, the effects of propagation of acoustic waves in the ground layer of the atmosphere. The factors of propagation sound in the open air have been determined. Approaches to the tracing of sound rays in conditions of atmospheric refraction have been analyzed. The use of a heuristic modification of the sound ray tracing model has been proposed, which provides that vertical profiles of real sound velocities in many cases can be approximated to a linear velocity profile of sound. Modeling of sound rays with one and two reflection points has been carried out. An improvement in the general model of the aircraft noise propagation with allowance for the refraction effect has been proposed, which allows taking into account atmospheric conditions, namely, the temperature gradient and the wind velocity gradient in the vertical plane. Originality. The research of the impact of sound rays refraction in the open air depending on meteorological conditions in the airport area has been carry out. Practical value. It has been revealed that it is precisely the simultaneous presence of a velocity sound gradient at the expense of the wind speed gradient and the temperature gradient create certain conditions that have a significant effect on the propagation sound model, which can not be neglected.
Authors and Affiliations
L. Levchenko, O. Zaporozhets
Keywords
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