Nonlinear Stability of Ekman Boundary Layers in Rotation Stratified Fluids

Nonlinear Stability of Ekman Boundary Layers in Rotation Stratified Fluids PDF Author: Hajime Koba
Publisher:
ISBN: 9781470414856
Category : Fluid mechanics
Languages : en
Pages : 132

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Book Description
A stationary solution of the rotating Navier-Stokes equations with a boundary condition is called an Ekman boundary layer. This book constructs stationary solutions of the rotating Navier-Stokes-Boussinesq equations with stratification effects in the case when the rotating axis is not necessarily perpendicular to the horizon. The author calls such stationary solutions Ekman layers. This book shows the existence of a weak solution to an Ekman perturbed system, which satisfies the strong energy inequality. Moreover, the author discusses the uniqueness of weak solutions and computes the decay rate of weak solutions with respect to time under some assumptions on the Ekman layers and the physical parameters. The author also shows that there exists a unique global-in-time strong solution of the perturbed system when the initial datum is sufficiently small. Comparing a weak solution satisfying the strong energy inequality with the strong solution implies that the weak solution is smooth with respect to time when time is sufficiently large.

Nonlinear Stability of Ekman Boundary Layers in Rotation Stratified Fluids

Nonlinear Stability of Ekman Boundary Layers in Rotation Stratified Fluids PDF Author: Hajime Koba
Publisher:
ISBN: 9781470414856
Category : Fluid mechanics
Languages : en
Pages : 132

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Book Description
A stationary solution of the rotating Navier-Stokes equations with a boundary condition is called an Ekman boundary layer. This book constructs stationary solutions of the rotating Navier-Stokes-Boussinesq equations with stratification effects in the case when the rotating axis is not necessarily perpendicular to the horizon. The author calls such stationary solutions Ekman layers. This book shows the existence of a weak solution to an Ekman perturbed system, which satisfies the strong energy inequality. Moreover, the author discusses the uniqueness of weak solutions and computes the decay rate of weak solutions with respect to time under some assumptions on the Ekman layers and the physical parameters. The author also shows that there exists a unique global-in-time strong solution of the perturbed system when the initial datum is sufficiently small. Comparing a weak solution satisfying the strong energy inequality with the strong solution implies that the weak solution is smooth with respect to time when time is sufficiently large.

Nonlinear Stability of Ekman Boundary Layers in Rotating Stratified Fluids

Nonlinear Stability of Ekman Boundary Layers in Rotating Stratified Fluids PDF Author: Hajime Koba
Publisher: American Mathematical Soc.
ISBN: 0821891332
Category : Mathematics
Languages : en
Pages : 142

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Book Description
A stationary solution of the rotating Navier-Stokes equations with a boundary condition is called an Ekman boundary layer. This book constructs stationary solutions of the rotating Navier-Stokes-Boussinesq equations with stratification effects in the case when the rotating axis is not necessarily perpendicular to the horizon. The author calls such stationary solutions Ekman layers. This book shows the existence of a weak solution to an Ekman perturbed system, which satisfies the strong energy inequality. Moreover, the author discusses the uniqueness of weak solutions and computes the decay rate of weak solutions with respect to time under some assumptions on the Ekman layers and the physical parameters. The author also shows that there exists a unique global-in-time strong solution of the perturbed system when the initial datum is sufficiently small. Comparing a weak solution satisfying the strong energy inequality with the strong solution implies that the weak solution is smooth with respect to time when time is sufficiently large.

The Theory of Rotating Fluids

The Theory of Rotating Fluids PDF Author: Harvey Philip Greenspan
Publisher: H, P. Greenspan
ISBN:
Category : Science
Languages : en
Pages : 414

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Book Description


Boundary and Shear Layers in Rotating and Stratified Fluids

Boundary and Shear Layers in Rotating and Stratified Fluids PDF Author: Yves Jean François Desaubies
Publisher:
ISBN:
Category : Boundary layer
Languages : en
Pages : 218

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Book Description


Rotating Fluids in Geophysics

Rotating Fluids in Geophysics PDF Author: Paul Harry Roberts
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 582

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Book Description
The subject of rotating fluids is worth studying for many reasons, not least of which is that all large scale motions of the Earth's atmosphere, oceans and core are dominated by its rotation. Trade winds follow lines of latitude because of rotation: the effect of these winds upon the Atlantic generates, in gyroscopic fashion, the intense northerly flowing Gulf Stream: and evidence of the impact of rotation on the Earth's core is seen in the northwardd pointing compass. However, the study of rotating fluids has also been characterized by the power, elegance and ingenuity of the experimental and theoretical tools which have been brought to bear on it - tools of which every fluid mechanist ought to be aware. This book is devoted primarily to a theoretical exposition of the subject, although several sections are centred on experimental and numerical techniques in their applications to the atmosphere, oceans and core of the Earth. A theme running through the book is waves and stability, supported by a brief section expounding hydrodynamic stability theory.

Small Viscosity and Boundary Layer Methods

Small Viscosity and Boundary Layer Methods PDF Author: Guy Métivier
Publisher: Springer Science & Business Media
ISBN: 0817682147
Category : Mathematics
Languages : en
Pages : 208

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Book Description
* Metivier is an expert in the field of pdes/math physics, with a particular emphasis on shock waves. * New monograph focuses on mathematical methods, models, and applications of boundary layers, present in many problems of physics, engineering, fluid mechanics. * Metivier has good Birkhauser track record: one of the main authors of "Advances in the Theory of Shock Waves" (Freistuehler/Szepessy, eds, 4187-4). * Manuscript endorsed by N. Bellomo, MSSET series editor...should be a good sell to members of MSSET community, who by-in-large are based in Europe. * Included are self-contained introductions to different topics such as hyperbolic boundary value problems, parabolic systems, WKB methods, construction of profiles, introduction to the theory of Evans’ functions, and energy methods with Kreiss’ symmetrizers.

Rotating Fluids in Geophysical and Industrial Applications

Rotating Fluids in Geophysical and Industrial Applications PDF Author: E.J. Hopfinger
Publisher: Springer
ISBN: 3709126029
Category : Science
Languages : en
Pages : 369

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Book Description
The volume presents a comprehensive overview of rotation effects on fluid behavior, emphasizing non-linear processes. The subject is introduced by giving a range of examples of rotating fluids encountered in geophysics and engineering. This is then followed by a discussion of the relevant scales and parameters of rotating flow, and an introduction to geostrophic balance and vorticity concepts. There are few books on rotating fluids and this volume is, therefore, a welcome addition. It is the first volume which contains a unified view of turbulence in rotating fluids, instability and vortex dynamics. Some aspects of wave motions covered here are not found elsewhere.

Compressible-incompressible Transitions in Fluid Mechanics

Compressible-incompressible Transitions in Fluid Mechanics PDF Author: Edoardo Bocchi
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
This manuscript deals with compressible-incompressible transitions arising in partial differential equations of fluid mechanics. We investigate two problems: floating structures and rotating fluids. In the first problem, the introduction of a floating object into water waves enforces a constraint on the fluid and the governing equations turn out to have a compressible-incompressible structure. In the second problem, the motion of geophysical compressible fluids is affected by the Earth's rotation and the study of the high rotation limit shows that the velocity vector field tends to be horizontal and with an incompressibility constraint.Floating structures are a particular example of fluid-structure interaction, in which a partially immersed solid is floating at the fluid surface. This mathematical problem models the motion of wave energy converters in sea water. In particular, we focus on heaving buoys, usually implemented in the near-shore zone, where the shallow water asymptotic models describe accurately the motion of waves. We study the two-dimensional nonlinear shallow water equations in the axisymmetric configuration in the presence of a floating object with vertical side-walls moving only vertically. The assumptions on the solid permit to avoid the free boundary problem associated with the moving contact line between the air, the water and the solid. Hence, in the domain exterior to the solid the fluid equations can be written as an hyperbolic quasilinear initial boundary value problem. This couples with a nonlinear second order ODE derived from Newton's law for the free solid motion. Local in time well-posedness of the coupled system is shown provided some compatibility conditions are satisfied by the initial data in order to generate smooth solutions.Afterwards, we address a particular configuration of this fluid-structure interaction: the return to equilibrium. It consists in releasing a partially immersed solid body into a fluid initially at rest and letting it evolve towards its equilibrium position. A different hydrodynamical model is used. In the exterior domain the equations are linearized but the nonlinear effects are taken into account under the solid. The equation for the solid motion becomes a nonlinear second order integro-differential equation which rigorously justifies the Cummins equation, assumed by engineers to govern the motion of floating objects. Moreover, the equation derived improves the linear approach of Cummins by taking into account the nonlinear effects. The global existence and uniqueness of the solution is shown for small data using the conservation of the energy of the fluid-structure system.In the second part of the manuscript, highly rotating fluids are studied. This mathematical problem models the motion of geophysical flows at large scales affected by the Earth's rotation, such as massive oceanic and atmospheric currents. The motion is also influenced by the gravity, which causes a stratification of the density in compressible fluids. The rotation generates anisotropy in viscous flows and the vertical turbulent viscosity tends to zero in the high rotation limit. Our interest lies in this singular limit problem taking into account gravitational and compressible effects. We study the compressible anisotropic Navier-Stokes-Coriolis equations with gravitational force in the horizontal infinite slab with no-slip boundary condition. Both this condition and the Coriolis force cause the apparition of Ekman layers near the boundary. They are taken into account in the analysis by adding corrector terms which decay in the interior of the domain. In this work well-prepared initial data are considered. A stability result of global weak solutions is shown for power-type pressure laws. The limit dynamics is described by a two-dimensional viscous quasi-geostrophic equation with a damping term that accounts for the boundary layers.

Stability of Time Dependent and Spatially Varying Flows

Stability of Time Dependent and Spatially Varying Flows PDF Author: Douglas L. Dwoyer
Publisher:
ISBN:
Category : Aerodynamics
Languages : en
Pages : 372

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Book Description


Numerical Solution of the Nonlinear Stability of an Imcompressible Ekman Boundary Layer

Numerical Solution of the Nonlinear Stability of an Imcompressible Ekman Boundary Layer PDF Author: Hans Bruun Nielsen
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description