Nordita Astrophysics seminars

Turbulent Transport of Extended and Interacting Particles: Beyond the Spherical Particle Approximation

by S.S. Ray (International Center for Theoretical Sciences, Tata Institute of Fundamental Research, Bangalore)

A string of tracers, interacting elastically, in a turbulent flow, shows a dramatically different behaviour when compared to the non-interacting case. Such an elastic chain shows strong preferential sampling of the turbulent flow unlike the usual tracer limit: an elastic chain is trapped in the vortical regions. The degree of preferential sampling and its dependence on the elasticity of the chain is quantified via the Okubo-Weiss parameter. The effect of modifying the deformability of the chain, via the number of links that form it, is also examined. We then end with recent results which suggest that suitable choice of particle interactions can lead to either crystalline phases in particle-aggregates or collective behaviour reminiscent of flocking in the natural world. Refs. 1. A Gupta, A. Roy, A. Saha, and S. S. Ray. ArXiv: 1901:xxxx (2019). 2. M. Gupta, P. Chaudhuri, J. Bec and S. S. Ray. ArXiv: 1812.06487 (2018). 3. J. R. Picardo, D. Vincenzi, N. Pal, and S. S. Ray. Phys. Rev. Lett. 121, 244501 (2018). 4. A. Choudhary, D. Venkataraman, and S. S. Ray. Europhys. Lett., 112, 24005 (2015)