Nonlinear nonmodal stability theory

RR Kerswell - Annual Review of Fluid Mechanics, 2018 - annualreviews.org
This review discusses a recently developed optimization technique for analyzing the
nonlinear stability of a flow state. It is based on a nonlinear extension of nonmodal analysis …

The lift-up effect: the linear mechanism behind transition and turbulence in shear flows

L Brandt - European Journal of Mechanics-B/Fluids, 2014 - Elsevier
The formation and amplification of streamwise velocity perturbations induced by cross-
stream disturbances is ubiquitous in shear flows. This disturbance growth mechanism, so …

On the stability threshold for the 3D Couette flow in Sobolev regularity

J Bedrossian, P Germain, N Masmoudi - Annals of Mathematics, 2017 - projecteuclid.org
We study Sobolev regularity disturbances to the periodic, plane Couette flow in the 3D
incompressible Navier-Stokes equations at high Reynolds number Re. Our goal is to …

Nonlinear input/output analysis: application to boundary layer transition

G Rigas, D Sipp, T Colonius - Journal of Fluid Mechanics, 2021 - cambridge.org
We extend linear input/output (resolvent) analysis to take into account nonlinear triadic
interactions by considering a finite number of harmonics in the frequency domain using the …

Transition threshold for the 2-D Couette flow in a finite channel

Q Chen, T Li, D Wei, Z Zhang - Archive for rational mechanics and …, 2020 - Springer
In this paper, we study the transition threshold problem for the 2-D Navier–Stokes equations
around the Couette flow (y, 0) at high Reynolds number Re in a finite channel. We develop a …

Transition threshold for the 3D Couette flow in Sobolev space

D Wei, Z Zhang - Communications on Pure and Applied …, 2021 - Wiley Online Library
In this paper, we study the transition threshold of the 3D Couette flow in Sobolev space at
high Reynolds number Re. It was proved that if the initial velocity v 0 satisfies for some c 0> …

Stability of the Couette flow at high Reynolds numbers in two dimensions and three dimensions

J Bedrossian, P Germain, N Masmoudi - Bulletin of the American …, 2019 - ams.org
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Mathematical Society American Mathematical Society MathSciNet Bookstore Publications …

An optimization approach for analysing nonlinear stability with transition to turbulence in fluids as an exemplar

RR Kerswell, CCT Pringle… - Reports on Progress in …, 2014 - iopscience.iop.org
This article introduces and reviews recent work using a simple optimization technique for
analysing the nonlinear stability of a state in a dynamical system. The technique can be …

Minimal seeds for shear flow turbulence: using nonlinear transient growth to touch the edge of chaos

CCT Pringle, AP Willis, RR Kerswell - Journal of Fluid Mechanics, 2012 - cambridge.org
We propose a general strategy for determining the minimal finite amplitude disturbance that
triggers transition to turbulence in shear flows. This involves constructing a variational …

Linear stability analysis of channel flow of viscoelastic Oldroyd-B and FENE-P fluids

M Zhang, I Lashgari, TA Zaki, L Brandt - Journal of fluid mechanics, 2013 - cambridge.org
We study the modal and non-modal linear instability of inertia-dominated channel flow of
viscoelastic fluids modelled by the Oldroyd-B and FENE-P closures. The effects of polymer …