Creation of an isolated turbulent blob fed by vortex rings

Turbulence is generated in a quiescent environment using vortex rings as building blocks. Turbulence is hard to control. Many experimental methods have been developed to generate this elusive state of matter, leading to fundamental insights into its statistical and structural features as well as its onset. In all cases, however, the material boundaries of the experimental apparatus pose a challenge for understanding what the turbulence has been fed and how it would freely evolve. Here we build and control a confined state of turbulence using elemental building blocks-vortex rings. We create a stationary and isolated blob of turbulence in a quiescent environment, initiated and sustained solely by vortex rings. We assemble a full picture of its three-dimensional structure, onset, energy budget and tunability. The incoming vortex rings can be endowed with conserved quantities, such as helicity, which can then be controllably transferred to the turbulent state. Our one-eddy-at-a-time approach opens the possibility for sculpting turbulent flows much as a state of matter, placing the turbulent blob at the targeted position, localizing it and ultimately harnessing it.

Automated summary

Researchers have generated and controlled a confined state of turbulence using vortex rings as building blocks. They have studied its three-dimensional structure, energy budget, and tunability. This approach opens up new possibilities for sculpting and harnessing turbulent flows.