ABSTRACT:
In flow ranges of interest, wall-bounded shear flows typically exhibit bistability of a basic state (steady, unidirectional) and a more complicated time-dependent 3D state usually labeled turbulence. A key (obvious) question is then understanding how to trigger transition between the two by instantaneously disturbing the system. I will talk about a variational approach to tackling this question illustrated in systems ranging from the simplest model of a fluid you will ever see (!) to the most complicated (fully 3D computations of the Navier-Stokes equations). The approach is general and easily applicable to other dynamical systems where one is interested in identifying basin boundaries.
ADDITIONAL INFORMATION:
Richard Kerswell’s interests include the Navier-Stokes equation (nonlinear dynamics, transition and turbulence), geophysical and astrophysical fluid mechanics (e.g., magnetic field generation, convecting and stably-stratified flows, rapidly-rotating systems), and granular media (dense transient flows). http://www.maths.bris.ac.uk/~marrk