Abstract
Triggering Turbulence Efficiently: Nonlinear Transient Growth, Minimal Seeds and Passive Control
Rich Kerswell
University of Cambridge
I will discuss the results of recent work applying a nonlinear optimisation technique to the shear flow transition problem.
This technique extends now well-known (linear) transient growth analysis to finite amplitude with the aim of detecting the `best' way - the minimal seed - to disturb a system out of the basic (laminar) state's basin of attraction (see Kerswell, Pringle & Willis, Rep. Prog. Phys. 77 085901, 2014 for a review). An example will be given of how this new capability can be used to design more nonlinearly stable flows and then possible future directions will be outlined.
This technique extends now well-known (linear) transient growth analysis to finite amplitude with the aim of detecting the `best' way - the minimal seed - to disturb a system out of the basic (laminar) state's basin of attraction (see Kerswell, Pringle & Willis, Rep. Prog. Phys. 77 085901, 2014 for a review). An example will be given of how this new capability can be used to design more nonlinearly stable flows and then possible future directions will be outlined.