Generation and decay of turbulence in an abruptly stopped Taylor-Couette flow

This study presents an innovative approach towards the generation and decay of turbulence in the Taylor-Couette system. The cylinders were brought to an abrupt stoppage that generated turbulence in the system, which was initially in the laminar flow region. Two different experimental approaches, namely visualizations and stereo-PIV measurements, were used to better understand the presented phenomenon for three different configurations at multiple rotation rates but always starting in the laminar flow region: only external cylinder, co-rotation and counter-rotation. For only external cylinder rotation, the lowest threshold limit of outer Reynolds number was found to be Re_o=693, which could be lowered with co- or counter-rotation to a minimal value of Re_o=433 . Axial wave-number increased with increasing rotation rate, and decay time to achieve complete laminar state was found to be around 40 seconds irrespective of the initial rotation rate. On the other hand, if the initial state before abrupt stoppage was turbulent the turbulence decayed in the matter of few seconds. In contrast to the study of Verschoof et al. (2017), self-similar decay of turbulence was not observed.