- Series
- Colloquia
- Time
- Thursday, September 22, 2022 - 11:00am for 1 hour (actually 50 minutes)
- Location
- Skiles 006
- Speaker
- Predrag Cvitanović – School of Physics, Georgia Tech – predrag.cvitanovic@physics.gatech.edu – https://cns.gatech.edu/~predrag/
- Organizer
- Gong Chen, Benjamin Jaye, Tom Kelly
In the world of moderate, everyday turbulence of fluids flowing across planes and down pipes, a quiet revolution is taking place. Applied mathematicians can today compute 'exact coherent structures', i.e. numerically precise 3D, fully nonlinear Navier-Stokes solutions: unstable equilibria, traveling waves, and (relative) periodic orbits. Experiments carried out at Georgia Tech today yield measurements as detailed as the numerical simulations; our experimentalists measure 'exact coherent structures' and trace out their unstable manifolds. What emerges is a dynamical systems theory of low-Reynolds turbulence as a walk among sets of weakly unstable invariant solutions.
We take you on a tour of this newly breached, hitherto inaccessible territory. Mastery of fluid mechanics is no prerequisite, and perhaps a hindrance: the talk is aimed at anyone who had ever wondered why - if no cloud is ever seen twice - we know a cloud when we see one? And how do we turn that into mathematics?