Dynamics near the subcritical transition of the 3D Couette flow I : below threshold case /
"We study small disturbances to the periodic, plane Couette flow in the 3D incompressible Navier-Stokes equations at high Reynolds number Re. We prove that for sufficiently regular initial data of size [epsilon] [less than or equal to] c0Re-1 for some universal c0> 0, the solution is global,...
Clasificación: | Libro Electrónico |
---|---|
Autores principales: | , , |
Formato: | Electrónico eBook |
Idioma: | Inglés |
Publicado: |
Providence, RI :
American Mathematical Society,
[2020]
|
Colección: | Memoirs of the American Mathematical Society.
|
Temas: |
Fluid mechanics {For general continuum mechanics, see 74Axx, or other parts of 74-XX}
> Hydrodynamic stability
> Parallel shear flows.
Fluid mechanics {For general continuum mechanics, see 74Axx, or other parts of 74-XX}
> Hydrodynamic stability
> Nonlinear effects.
Fluid mechanics {For general continuum mechanics, see 74Axx, or other parts of 74-XX}
> Turbulence [See also 37-XX, 60Gxx, 60Jxx]
> Transition to turbulence.
Fluid mechanics {For general continuum mechanics, see 74Axx, or other parts of 74-XX}
> Turbulence [See also 37-XX, 60Gxx, 60Jxx]
> Shear flows.
|
Acceso en línea: | Texto completo |
Sumario: | "We study small disturbances to the periodic, plane Couette flow in the 3D incompressible Navier-Stokes equations at high Reynolds number Re. We prove that for sufficiently regular initial data of size [epsilon] [less than or equal to] c0Re-1 for some universal c0> 0, the solution is global, remains within O(c0) of the Couette flow in L2, and returns to the Couette flow as t [right arrow] [infinity]. For times t>/-Re1/3, the streamwise dependence is damped by a mixing-enhanced dissipation effect and the solution is rapidly attracted to the class of "2.5 dimensional" streamwise-independent solutions referred to as streaks. Our analysis contains perturbations that experience a transient growth of kinetic energy from O(Re-1) to O(c0) due to the algebraic linear instability known as the lift-up effect. Furthermore, solutions can exhibit a direct cascade of energy to small scales. The behavior is very different from the 2D Couette flow, in which stability is independent of Re, enstrophy experiences a direct cascade, and inviscid damping is dominant (resulting in a kind of inverse energy cascade). In 3D, inviscid damping will play a role on one component of the velocity, but the primary stability mechanism is the mixing-enhanced dissipation. Central to the proof is a detailed analysis of the interplay between the stabilizing effects of the mixing and enhanced dissipation and the destabilizing effects of the lift-up effect, vortex stretching, and weakly nonlinear instabilities connected to the non-normal nature of the linearization"-- |
---|---|
Notas: | "Forthcoming, volume 266, number 1294." |
Descripción Física: | 1 online resource (v, 170 pages) |
Bibliografía: | Includes bibliographical references. |
ISBN: | 1470462516 9781470462512 |