Comments on the low frequency radiation impedance of a duct exhausting a hot gas

Abraham Hirschberg, M. Hoeijmakers

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The influence of convection and temperature on the radiation impedance of an open duct termination exhausting a hot gas is commonly described by a complex theory. A simplified analytical expression is proposed for low frequencies. Both models assume a free jet with uniform velocity bounded by infinitely thin shear layers. The convective velocity that should be assumed when applying these models to a non-uniform outflow is uncertain. A simplified version of the so-called Vortex Sound Theory demonstrates that the convective velocity one should assume is lower than the jet centerline velocity.
Original languageEnglish
Pages (from-to)EL84-EL89
JournalJournal of the Acoustical Society of America
Issue number2
Publication statusPublished - 2014

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