Department of Physics

Indian Institute Of Technology Madras , Chennai

Turbulence: Dynamics, Geometry, and Topology

Speaker : Balachandra Suri, IST-Austria

2019-11-07

Abstract :

Turbulence is widely regarded as the last unsolved problem in classical physics. Despite the availability of accurate  governing equations, a tractable framework that describes both dynamical and statistical properties of turbulence has eluded scientists. In this talk, we discuss how chaos theory (developed for low-dimensional dynamical systems) may find application in solving  this outstanding problem. Specifically, we present a combined  experimental and numerical study of a moderately turbulent flow in an electromagnetically driven shallow fluid layer. Turbulent evolution in this system is punctuated by intervals of dramatic coherence, which is  a signature of unstable nonchaotic solutions (e.g., steady or time-periodic flows) of the Navier-Stokes equation.  Often termed Exact Coherent States (ECS),  such simple solutions form the chaotic saddle whose geometry and topology underpin  turbulent dynamics. For specific examples, we demonstrate that  turbulent evolution can be quantitatively and robustly forecast using ECS.  We also compare statistical properties of turbulence with those of ECS.

Key Speaker Balachandra Suri, IST-Austria
Guests None
Place Seminar Room
Start Time 11:00 AM
Finish Time 12:00 PM
External Link None