Three-dimensional instability in flow over a backward-facing step
Abstract
Results are reported from a three-dimensional computational stability analysis of flow over a backward-facing step with an expansion ratio (outlet to inlet height) of 2 at Reynolds numbers between 450 and 1050. The analysis shows that the first absolute linear instability of the steady two-dimensional flow is a steady three-dimensional bifurcation at a critical Reynolds number of 748. The critical eigenmode is localized to the primary separation bubble and has a flat roll structure with a spanwise wavelength of 6.9 step heights. The system is further shown to be absolutely stable to two-dimensional perturbations up to a Reynolds number of 1500. Stability spectra and visualizations of the global modes of the system are presented for representative Reynolds numbers.
Additional Information
"Reprinted with the permission of Cambridge University Press." (Received 10 April 2002 and in revised form 1 July 2002) Published Online 13 Dec 2002 We thank G. Brown and P. Marcus for many useful discussions on the topic of centrifugal instability. M. G. M. G. acknowledges support from the EPSRC, UK and the FCT, Portugal, and the hospitality of the IMA, University of Minnesota, where part of this research was carried out. R. H. H. acknowledges support from the NSF.Files
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Additional details
- Eprint ID
- 1835
- Resolver ID
- CaltechAUTHORS:BARjfm02
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2006-02-20Created from EPrint's datestamp field
- Updated
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2021-11-08Created from EPrint's last_modified field