Statistical analysis of the transition to turbulence in plane Couette flow

1998 ◽  
Vol 6 (1) ◽  
pp. 143-155 ◽  
Author(s):  
S. Bottin ◽  
H. Chaté
Keyword(s):  
Statistical Analysis ◽  
Couette Flow ◽  
Transition To Turbulence ◽  
Plane Couette Flow

scholarly journals Doubly localized states in plane Couette flow

2014 ◽  
Vol 758 ◽  
pp. 1-4 ◽  
Author(s):  
Bruno Eckhardt
Keyword(s):  
Couette Flow ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Linear Instability ◽  
Localized States ◽  
Transition To Turbulence ◽  
Navier Stokes ◽  
Plane Couette Flow ◽  
Navier Stokes Equation ◽  
Navier Stokes Equations

AbstractMuch of our understanding of the transition to turbulence in flows without a linear instability came with the discovery and characterization of fully three-dimensional solutions to the Navier–Stokes equation. The first examples in plane Couette flow were periodic in both spanwise and streamwise directions, and could explain the transitions in small domains only. The presence of localized turbulent spots in larger domains, the spatiotemporal decoherence on larger scales and the ability to trigger turbulence with pointwise perturbations require solutions that are localized in both directions, like the one presented by Brand & Gibson (J. Fluid Mech., vol. 750, 2014, R3). They describe a steady solution of the Navier–Stokes equations and characterize in unprecedented detail, including an analytic computation of its localization properties. The study opens up new ways to describe localized turbulent patches.

scholarly journals Dynamics of spatially localized states in transitional plane Couette flow

2019 ◽  
Vol 867 ◽  
pp. 414-437 ◽  
Author(s):  
Anton Pershin ◽  
Cédric Beaume ◽  
Steven M. Tobias
Keyword(s):  
Reynolds Number ◽  
Couette Flow ◽  
Initial Conditions ◽  
Reynolds Numbers ◽  
Localized States ◽  
Transition To Turbulence ◽  
Dynamical Structure ◽  
Plane Couette Flow ◽  
Homoclinic Snaking ◽  
Chaotic Transients

Unsteady spatially localized states such as puffs, slugs or spots play an important role in transition to turbulence. In plane Couette flow, steady versions of these states are found on two intertwined solution branches describing homoclinic snaking (Schneider et al., Phys. Rev. Lett., vol. 104, 2010, 104501). These branches can be used to generate a number of spatially localized initial conditions whose transition can be investigated. From the low Reynolds numbers where homoclinic snaking is first observed ($Re<175$) to transitional ones ($Re\approx 325$), these spatially localized states traverse various regimes where their relaminarization time and dynamics are affected by the dynamical structure of phase space. These regimes are reported and characterized in this paper for a $4\unicode[STIX]{x03C0}$-periodic domain in the streamwise direction as a function of the two remaining variables: the Reynolds number and the width of the localized pattern. Close to the snaking, localized states are attracted by spatially localized periodic orbits before relaminarizing. At larger values of the Reynolds number, the flow enters a chaotic transient of variable duration before relaminarizing. Very long chaotic transients ($t>10^{4}$) can be observed without difficulty for relatively low values of the Reynolds number ($Re\approx 250$).

Dynamical systems and the transition to turbulence in linearly stable shear flows

2007 ◽  
Vol 366 (1868) ◽  
pp. 1297-1315 ◽  
Author(s):  
Bruno Eckhardt ◽  
Holger Faisst ◽  
Armin Schmiegel ◽  
Tobias M Schneider
Keyword(s):  
Couette Flow ◽  
Coherent Structures ◽  
Pipe Flow ◽  
Temporal Evolution ◽  
Initial Conditions ◽  
Transition To Turbulence ◽  
Plane Couette Flow ◽  
Numerical Studies ◽  
Lifetime Studies ◽  
Transition Scenario

Plane Couette flow and pressure-driven pipe flow are two examples of flows where turbulence sets in while the laminar profile is still linearly stable. Experiments and numerical studies have shown that the transition has features compatible with the formation of a strange saddle rather than an attractor. In particular, the transition depends sensitively on initial conditions and the turbulent state is not persistent but has an exponential distribution of lifetimes. Embedded within the turbulent dynamics are coherent structures, which transiently show up in the temporal evolution of the turbulent flow. Here we summarize the evidence for this transition scenario in these two flows, with an emphasis on lifetime studies in the case of plane Couette flow and on the coherent structures in pipe flow.

scholarly journals Recurrent motions within plane Couette turbulence

2007 ◽  
Vol 580 ◽  
pp. 339-358 ◽  
Author(s):  
D. VISWANATH
Keyword(s):  
Periodic Solutions ◽  
Couette Flow ◽  
Boundary Layers ◽  
Coherent Structures ◽  
Three Dimensional ◽  
Turbulent Boundary Layers ◽  
Transition To Turbulence ◽  
Good Resolution ◽  
Plane Couette Flow ◽  
Near Wall

The phenomenon of bursting, in which streaks in turbulent boundary layers oscillate and then eject low-speed fluid away from the wall, has been studied experimentally, theoretically and computationally for more than 50 years because of its importance to the three-dimensional structure of turbulent boundary layers. Five new three-dimensional solutions of turbulent plane Couette flow are produced, one of which is periodic while the other four are relative periodic. Each of these five solutions demonstrates the breakup and re-formation of near-wall coherent structures. Four of our solutions are periodic, but with drifts in the streamwise direction. More surprisingly, two of our solutions are periodic, but with drifts in the spanwise direction, a possibility that does not seem to have been considered in the literature. It is argued that a considerable part of the streakiness observed experimentally in the near-wall region could be due to spanwise drifts that accompany the breakup and re-formation of coherent structures. A new periodic solution of plane Couette flow is also computed that could be related to transition to turbulence.The violent nature of the bursting phenomenon implies the need for good resolution in the computation of periodic and relative periodic solutions within turbulent shear flows. This computationally demanding requirement is addressed with a new algorithm for computing relative periodic solutions one of whose features is a combination of two well-known ideas – namely the Newton–Krylov iteration and the locally constrained optimal hook step. Each of the six solutions is accompanied by an error estimate.Dynamical principles are discussed that suggest that the bursting phenomenon, and more generally fluid turbulence, can be understood in terms of periodic and relative periodic solutions of the Navier–Stokes equation.

scholarly journals Forced Linear Shear Flows with Rotation: Rotating Couette–Poiseuille Flow, Its Stability, and Astrophysical Implications

2021 ◽  
Vol 922 (2) ◽  
pp. 161
Author(s):  
Subham Ghosh ◽  
Banibrata Mukhopadhyay
Keyword(s):  
Shear Flow ◽  
Couette Flow ◽  
Accretion Disk ◽  
Poiseuille Flow ◽  
Small Region ◽  
Transition To Turbulence ◽  
Plane Couette Flow ◽  
Plane Poiseuille Flow ◽  
Plane Shear ◽  
Linear Shear

Abstract We explore the effect of forcing on the linear shear flow or plane Couette flow, which is also the background flow in the very small region of the Keplerian accretion disk. We show that depending on the strength of forcing and boundary conditions suitable for the systems under consideration, the background plane shear flow, and hence the accretion disk velocity profile, is modified into parabolic flow, which is a plane Poiseuille flow or Couette–Poiseuille flow, depending on the frame of reference. In the presence of rotation, the plane Poiseuille flow becomes unstable at a smaller Reynolds number under pure vertical as well as three-dimensional perturbations. Hence, while rotation stabilizes the plane Couette flow, the same destabilizes the plane Poiseuille flow faster and hence the forced local accretion disk. Depending on the various factors, when the local linear shear flow becomes a Poiseuille flow in the shearing box due to the presence of extra force, the flow becomes unstable even for Keplerian rotation, and hence turbulence will ensue. This helps to resolve the long-standing problem of subcritical transition to turbulence in hydrodynamic accretion disks and the laboratory plane Couette flow.

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