Host: Science Council of Japan
Co-host: Architectural Institute of Japan, Japan Association for Wind Engineering, The Institute of Electrical Engineering of Japan, Japan Society of Steel Construction, Japan Society of Civil Engineering, Meteorological Society of Japan
Pages 16
Large scale sound propagation through the atmosphere is influenced by the local wind conditions. The wind prevents straight paths of the sound waves and may result in “abnormal sounds”. The objective of the present study is to simulate this class of sound propagation problems, in which the ambient medium is moving. The basic wave equations are derived from the governing equations of the compressible inviscid fluid for the cases of steady wind profiles. The wave equation is transformed to a Helmholtz type equation with respect to the complex pressure amplitude. The present paper focuses on the availability of these basic equations. The standard Galerkin finite element method is applied to solve the Helmholtz type equation. The complex acoustic pressure amplitude, the solution variable, is discretized by the linear triangular elements. An infinite element is employed for the radiation boundary condition. Two cases of numerical examples, in one case the wind profile is uniform and in the other case the wind profile is exponential, are presented in order to demonstrate the effect of wind conditions on sound propagation.
