LIFETIME OF TURBULENT PATCH IN TAYLOR COUETTE SETUP

etc15 Tracking Number 502

In linearly stable shear flows like pipe and plane Couette flows, the transition from the laminar to the turbulent regime occurs abruptly. To better understand this transition, the time evolution of turbulent patches, created by controlled finite amplitude perturbations, have been studied in the literature. These studies mostly focused on pipe flows for which a finite lifetime of the patch was proven. The same conclusion was drawn in the only available study performed in a Taylor Couette setup. Here, we measured the lifetime in a different size TC setup. We show that the lifetime is indeed finite and also very sensitive to the boundary condition, but not much to the perturbation mechanism. We suggest that in addition to the Reynolds number, the lifetime depends on the aspect ratio to the radius ratio of the setup.