Transient growth of perturbations in Stokes oscillatory flows

Autor: Damien Biau
Přispěvatelé: Laboratoire de Dynamique des Fluides (DynFluid), Conservatoire National des Arts et Métiers [CNAM] (CNAM)-Arts et Métiers Sciences et Technologies, HESAM Université (HESAM)-HESAM Université (HESAM)
Jazyk: angličtina
Rok vydání: 2016
Předmět:
Zdroj: Journal of Fluid Mechanics
Journal of Fluid Mechanics, Cambridge University Press (CUP), 2016, 794, pp.10. ⟨10.1017/jfm.2016.210⟩
ISSN: 0022-1120
1469-7645
DOI: 10.1017/jfm.2016.210⟩
Popis: International audience; Oscillatory Stokes flows, with zero mean, are subjected to subcritical transition to turbulence. The maximal energy growth of perturbations is computed in the subcritical regime through an optimisation method. The results show strong amplifications during half a period. The energy transfer from the base flow involves an Orr mechanism with two-dimensional vorticity waves, and the maximum energy scales exponentially with the Reynolds number. Nonlinear simulations show that low-energy perturbations are sufficient to trigger turbulent flow.
Databáze: OpenAIRE