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    Accepted author manuscript, 6.06 MB, PDF document

The path of laminar-to-turbulent transition behind a backward-facing step (BFS) in the supersonic regime at Ma = 1.7 and Reδ0 = 13718 is investigated using a very well-resolved large eddy simulation (LES). Five distinct stages are identified in the transition process by the visualisation of instantaneous flow. The transition is initiated by a Kelvin-Helmholtz (K-H) instability of the separated shear layer, followed by secondary modal instabilities of the distorted K-H vortices, leading to Λ-shaped vortices, hair-pin vortices and finally to a fully turbulent state around the reattachment location. Spectral analysis and proper orthogonal decomposition (POD) reveal that the low-frequency breathing dynamics also plays a major role in the transition process.

Original languageEnglish
Title of host publicationProceedings of the 11th International Symposium on Turbulence and Shear Flow Phenomena, TSFP 2019
Subtitle of host publication30/07/19 - 2/08/19 Southampton, United Kingdom
Number of pages6
Publication statusPublished - 1 Jan 2019
Event11th International Symposium on Turbulence and Shear Flow Phenomena, TSFP 2019 - Southampton, United Kingdom
Duration: 30 Jul 20192 Aug 2019

Conference

Conference11th International Symposium on Turbulence and Shear Flow Phenomena, TSFP 2019
CountryUnited Kingdom
CitySouthampton
Period30/07/192/08/19

ID: 62602408