EFFECT OF MEAN FLOWSHEAR ON SOUND PROPAGATION IN UNIFORM CIRCULAR DUCTS
2016 (English)In: PROCEEDINGS OF THE 23RD INTERNATIONAL CONGRESS ON SOUND AND VIBRATION: FROM ANCIENT TO MODERN ACOUSTICS, 2016Conference paper (Refereed)
Acoustic measurements based on multi-port models are commonly applied to investigate generation or scattering behaviors of in-duct components (turbocharger, mufflers, etc.) in confined flows. These multi-port models usually require information about the sound attenuations and the mode shapes of the cut-on higher-order acoustic modes in the rigid-wall duct. Although there are well-established models for determining theses parameters, most of the models are based on a uniform-flow assumption which neglects the refraction effects of the mean flow shear on the sound propagation. To understand the importance of the refraction effects, a numerical investigation is conducted to study the influence of the transverse mean-velocity gradients on the viscothermal damping and mode shapes of both the fundamental and higher-order modes in uniform circular ducts with rigid walls. The investigation is based on the linearized Navier-Stokes equations (LNSE) formulated in the frequency domain and several prescribed shear mean-velocity profiles (one turbulent boundary layer profile and two exponential-then-uniform profiles). The numerical results are compared with a model based on the uniform-flow assumption.
Place, publisher, year, edition, pages
Proceedings of the International Congress on Sound and Vibration, ISSN 2329-3675
IdentifiersURN: urn:nbn:se:kth:diva-203207ISI: 000388480403128ISBN: 978-960-99226-2-3 OAI: oai:DiVA.org:kth-203207DiVA: diva2:1081238
23rd International Congress on Sound and Vibration (ICSV), JUL 10-14, 2016, Athens, GREECE
QC 201703132017-03-132017-03-132017-03-13Bibliographically approved