THRESHOLD AMPLITUDES IN SUBCRITICAL SHEAR FLOWS

摘要

Non-linear stability bounds are derived for subcritical shear flows. First the methodology is exemplified using a model problem and then it is applied to plane Couette flow. The result is a lower bound which scales as Re"4. Upper bounds based on numerical simulations are found to be about Re"1, depending slightly on the transition scenario investigated. Bounds for plane Poiseuille flow are also presented.