Supercritical transition to turbulence in an inertially-driven von Karman closed flow
| dc.creator | Ravelet, Florent | |
| dc.creator | Chiffaudel, Arnaud | |
| dc.creator | Daviaud, Francois | |
| dc.date | 2008-01-22 | |
| dc.date.accessioned | 2026-07-07T09:26:47Z | |
| dc.date.available | 2026-07-07T09:26:47Z | |
| dc.description | We study the transition from laminar flow to fully developed turbulence for an inertially-driven von Karman flow between two counter-rotating large impellers fitted with curved blades over a wide range of Reynolds number (100 - 1 000 000). The transition is driven by the destabilisation of the azimuthal shear-layer, i.e., Kelvin-Helmholtz instability which exhibits travelling/drifting waves, modulated travelling waves and chaos below the emergence of a turbulent spectrum. A local quantity -the energy of the velocity fluctuations at a given point- and a global quantity -the applied torque- are used to monitor the dynamics. The local quantity defines a critical Reynolds number Rec for the onset of time-dependence in the flow, and an upper threshold/crossover Ret for the saturation of the energy cascade. The dimensionless drag coefficient, i.e., the turbulent dissipation, reaches a plateau above this finite Ret, as expected for a "Kolmogorov"-like turbulence for Re -> infinity. Our observations suggest that the transition to turbulence in this closed flow is globally supercritical: the energy of the velocity fluctuations can be considered as an order parameter characterizing the dynamics from the first laminar time-dependence up to the fully developed turbulence. Spectral analysis in temporal domain moreover reveals that almost all of the fluctuations energy is stored in time-scales one or two orders of magnitude slower than the time-scale based on impeller frequency. | |
| dc.identifier | https://arxiv.org/abs/0801.3357 | |
| dc.identifier | http://arxiv.org/abs/0801.3357 | |
| dc.identifier | Journal of Fluid Mechanics 601 (2008) 339-364 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/156873 | |
| dc.subject | Fluid Dynamics | |
| dc.title | Supercritical transition to turbulence in an inertially-driven von Karman closed flow | |
| dc.type | text |