文章基本信息

标题：Numerical Analysis of Aerodynamic Noise Emitted from a Pantograph Based on Non-compact Green's Function
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作者：Takehisa TAKAISHI ; Akio SAGAWA ; Chisachi KATO 等
期刊名称：Journal of Environment and Engineering
电子版ISSN：1880-988X
出版年度：2010
卷号：5
期号：1
页码：84-96
DOI：10.1299/jee.5.84
出版社：The Japan Society of Mechanical Engineers
摘要：In this study, mathematical formulae for evaluating scattered components of non-compact sound are summarized, and aerodynamic noise emitted from a pantograph is predicted numerically based on the theory of vortex sound. When influence of reflection at the plane (train roof) is taken into consideration in Green's functions, interference of sound waves appears and amplitude of sound pressure at an observer located in a far field is strengthened and weakened periodically depending upon its frequency, which phenomenon is similar to the experimental results. In the low frequency range, large separations occurring at the upper and lower sides of a pantograph head, lower sides of the pantograph head support, and an upper frame are main sources of scattered sound propagating upward. In the high frequency range, sound seems to be generated by unsteady motion of small vortices shed from the pantograph head and the support. As for sound propagating sideward, release of large-scale vortices from the support and the upper frame in horizontal planes is responsible for low frequency noise, and longitudinal vortices rolling up along sides of the support seem to generate sound of high frequency.
关键词：Aerodynamic Noise;Numerical Simulation;Vortex;Non-Compact Green's Function