Abstract

An experimental study investigating the dynamics of a turbulent jet developing subject to Coriolis effects induced in a rotating fluid is summarized. The program appears to be the first PIV study of this type of flow. The measurements reveal how Coriolis effects substantially alter the flow dynamics of the jet in comparison to its non-rotating counterpart. In particular, the measurements confirm the existence of a time-periodic formation-breakdown cycle of the jet that was computationally predicted by Lawrie et al. (2011, J. Phys.: Conf. Ser. 318, 032048).

The data analysis shows that the frequency of the formation-breakdown cycle increases linearly with the background rotation rate. The onset of the breakdown phase and of the reformation phase of the cycle can be characterized in terms of a local Rossby number employing an internal velocity and associated length scale of the jet. The critical values for this local Rossby number, for onset of breakdown and reformation, scale linearly with a global Rossby number based on the flow conditions at the source. The analysis of the experimental data points towards centrifugal instability as the potential origin of the formation-breakdown cycle.