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[ July 01, 2019]
Coherent structures and extreme events in rotating multiphase turbulent flows
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- Speaker:
- Federico Toschi
- Date:
- June 27, 2019
- Time:
- 3:30-5:00pm
- Location:
- Room 210, COE Building No.1
- Host:
- Yantao Yang
- Abstract
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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.
- Biography
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Federico Toschi is full professor at the departments of Applied Physics and of Mathematics and Computer Science at Eindhoven University of Technology (TU/e). His research focuses on the emerging complexity in challenging multi-scale problems at the crossroad between statistical physics, fluid mechanics, soft condensed matter and bio-physics. Prof. Toschi’s research employs experimental, numerical and theoretical methods and covers -amongst others- fluid dynamics turbulence; Lagrangian turbulence; thermal convection; complex fluids; soft condensed matter; active matter; crowd dynamics; scientific computing and Lattice Boltzmann methods. Several of Prof. Toschi’s research topics are strongly interdisciplinary and involve pushing the boundaries of physics across different disciplines. In the computational aspects of his work he pursues innovation of numerical methods as well as large-scale, massively parallel, numerical simulations. His research is embedded in the 4TU Centre of Excellence for Multiscale Phenomena, the JMBC Burgers centrum for fluid dynamics, and the Eindhoven Multiscale Institute. He teaches general courses on fluid mechanics, mathematical and computational physics, dynamical systems and chaos for Applied Physics BSc and MSc students. He served the scientific community by chairing two COST Action on “Particles in turbulence” and “Flowing matter” and is editor of the Journal of Turbulence.