Titre : Transition to turbulence in plane Couette flow
Contact : Nicolas Mordant (équipe EDT)
Résumé/Abstract : We experimentally and numerically investigate the temporal aspects of turbulent spot spreading in a plane Couette flow for transitional Reynolds number between 300 and 450. Spot growth rate, spot advection rate and large-scale flow intensity are measured as a function of time and Reynolds number. All these quantities show similar dynamics enlightening the role played by large scale flows in the advection of the turbulent spot. The contributions of each possible growth mechanisms as growth by advection or growth by destabilization are discussed for the different stage of spot growth. A scenario which gathers all this elements is suggested and enables a more complete understanding of the growth dynamics of turbulent spots.