Coherent structures and extreme events in rotating multiphase turbulent flows

Abstract

By using direct numerical simulations (DNS) at unprecedented resolution we study turbulence under rotation in the presence of simultaneous direct and inverse cascades. The accumulation of energy at large scale leads to the formation of vertical coherent regions with high vorticity oriented along the rotation axis. By seeding the flow with millions of inertial particles, we quantify -for the first time- the effects of those coherent vertical structures on the preferential concentration of light and heavy particles. Furthermore, we quantitatively show that extreme fluctuations, leading to deviations from a normal-distributed statistics, result from the entangled interaction of the vertical structures with the turbulent background. Finally, we present the first-ever measurement of the relative importance between Stokes drag, Coriolis force and centripetal forces along the trajectories of inertial particles. We discover that vortical coherent structures lead to unexpected diffusion properties for heavy and light particles in the directions parallel and perpendicular to the rotation axis.

References in corpus (6)

• Scale interactions and scaling laws in rotating flows at moderate Rossby numbers and large Reynolds numbers
• Helicity cascades in rotating turbulence
• Scaling and energy transfer in rotating turbulence
• Rotating Taylor-Green Flow
• On the decrease of intermittency in decaying rotating turbulence
• On the third order structure function for rotating 3D homogeneous turbulent flow

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• Bistability of the large-scale dynamics in quasi-two-dimensional turbulence
• A closure theory for the split energy-helicity cascades in homogeneous isotropic homochiral turbulence