Page 1 Next

Displaying 1 – 20 of 33

Showing per page

Navier-Stokes equations on unbounded domains with rough initial data

Peer Christian Kunstmann (2010)

Czechoslovak Mathematical Journal

We consider the Navier-Stokes equations in unbounded domains Ω n of uniform C 1 , 1 -type. We construct mild solutions for initial values in certain extrapolation spaces associated to the Stokes operator on these domains. Here we rely on recent results due to Farwig, Kozono and Sohr, the fact that the Stokes operator has a bounded H -calculus on such domains, and use a general form of Kato’s method. We also obtain information on the corresponding pressure term.

New wall laws for the unsteady incompressible Navier-Stokes equations on rough domains

Gabriel R. Barrenechea, Patrick Le Tallec, Frédéric Valentin (2002)

ESAIM: Mathematical Modelling and Numerical Analysis - Modélisation Mathématique et Analyse Numérique

Different effective boundary conditions or wall laws for unsteady incompressible Navier-Stokes equations over rough domains are derived in the laminar setting. First and second order unsteady wall laws are proposed using two scale asymptotic expansion techniques. The roughness elements are supposed to be periodic and the influence of the rough boundary is incorporated through constitutive constants. These constants are obtained by solving steady Stokes problems and so they are calculated only once....

New Wall Laws for the Unsteady Incompressible Navier-Stokes Equations on Rough Domains

Gabriel R. Barrenechea, Patrick Le Tallec, Frédéric Valentin (2010)

ESAIM: Mathematical Modelling and Numerical Analysis

Different effective boundary conditions or wall laws for unsteady incompressible Navier-Stokes equations over rough domains are derived in the laminar setting. First and second order unsteady wall laws are proposed using two scale asymptotic expansion techniques. The roughness elements are supposed to be periodic and the influence of the rough boundary is incorporated through constitutive constants. These constants are obtained by solving steady Stokes problems and so they are calculated only...

Non-autonomous 2D Navier–Stokes system with a simple global attractor and some averaging problems

V. V. Chepyzhov, M. I. Vishik (2002)

ESAIM: Control, Optimisation and Calculus of Variations

We study the global attractor of the non-autonomous 2D Navier–Stokes system with time-dependent external force g ( x , t ) . We assume that g ( x , t ) is a translation compact function and the corresponding Grashof number is small. Then the global attractor has a simple structure: it is the closure of all the values of the unique bounded complete trajectory of the Navier–Stokes system. In particular, if g ( x , t ) is a quasiperiodic function with respect to t , then the attractor is a continuous image of a torus. Moreover the...

Non-autonomous 2D Navier–Stokes system with a simple global attractor and some averaging problems

V. V. Chepyzhov, M. I. Vishik (2010)

ESAIM: Control, Optimisation and Calculus of Variations

We study the global attractor of the non-autonomous 2D Navier–Stokes system with time-dependent external force g(x,t). We assume that g(x,t) is a translation compact function and the corresponding Grashof number is small. Then the global attractor has a simple structure: it is the closure of all the values of the unique bounded complete trajectory of the Navier–Stokes system. In particular, if g(x,t) is a quasiperiodic function with respect to t, then the attractor is a continuous image...

Numerical analysis of the Navier-Stokes equations

Rolf Rannacher (1993)

Applications of Mathematics

This paper discusses some conceptional questions of the numerical simulation of viscous incompressible flow which are related to the presence of boundaries.

Numerical approximation of flow in a symmetric channel with vibrating walls

Sváček, Petr, Horáček, Jaromír (2010)

Programs and Algorithms of Numerical Mathematics

In this paper the numerical solution of two dimensional fluid-structure interaction problem is addressed. The fluid motion is modelled by the incompressible unsteady Navier-Stokes equations. The spatial discretization by stabilized finite element method is used. The motion of the computational domain is treated with the aid of Arbitrary Lagrangian Eulerian (ALE) method. The time-space problem is solved with the aid of multigrid method. The method is applied onto a problem of interaction of channel...

Numerical modeling of the movement of a rigid particle in viscous fluid

Josef Ježek, Stanislav Saic, Karel Segeth (1999)

Applications of Mathematics

Modeling the movement of a rigid particle in viscous fluid is a problem physicists and mathematicians have tried to solve since the beginning of this century. A general model for an ellipsoidal particle was first published by Jeffery in the twenties. We exploit the fact that Jeffery was concerned with formulae which can be used to compute numerically the velocity field in the neighborhood of the particle during his derivation of equations of motion of the particle. This is our principal contribution...

Currently displaying 1 – 20 of 33

Page 1 Next