Open this publication in new window or tab >>2016 (English)In: Computers & Fluids, ISSN 0045-7930, E-ISSN 1879-0747, Vol. 140, p. 397-405Article in journal (Refereed) Published
Abstract [en]
A novel method is proposed to identify flow structures responsible for sound generation in confined flow past an inhibitor. Velocity fields obtained using Large Eddy Simulations (LES) are post-processed to compute the Finite Time Lyapunov Exponent (FTLE) field, the ridges of which in backward time represent an approximation to Lagrangian Coherent Structures (LCS), the structures that organize transport in the flow field. The flow-field is first decomposed using dynamic mode decomposition (DMD), and the organizing centers or vortices at the significant DMD frequencies are extracted. The results are then compared with the lambda(2) criterion. Features such as shear layer roll-up and development of secondary instabilities are more clearly visible in the FTLE field than with the lambda(2) criterion.
Place, publisher, year, edition, pages
Elsevier, 2016
Keywords
Aeroacoustics, Large eddy simulation (LES), Lagrangian coherent structures (LCS), Finite time Lyapunov exponents (FTLE), Dynamic mode decomposition (DMD)
National Category
Mechanical Engineering
Identifiers
urn:nbn:se:kth:diva-197766 (URN)10.1016/j.compfluid.2016.09.001 (DOI)000388048400032 ()2-s2.0-84992663769 (Scopus ID)
Note
QC 20161229
2016-12-292016-12-082017-06-28Bibliographically approved