All a b c d e f g h i j k l m n o p q r s t u v w x y z Other

Previous Page 3 Next

Displaying 41 – 60 of 68

Showing per page

Problème de Stokes et système de Navier-Stokes incompressible à densité variable dans le demi-espace

Raphaël Danchin, Piotr Bogusław Mucha (2008/2009)

Séminaire Équations aux dérivées partielles

On s’intéresse à la résolution du système de Navier-Stokes incompressible à densité variable dans le demi-espace ℝ + n : = ℝ n - 1 × ] 0 , ∞ [ en dimension n ≥ 3 . On considère des données initiales à régularité critique. On établit que si la densité initiale est proche d’une constante strictement positive dans L ∞ ∩ W ˙ 1 , n et si la vitesse initiale est petite par rapport à la viscosité dans l’espace de Besov homogène B ˙ n , 1 0 alors le système de Navier-Stokes admet une unique solution globale. La démonstration repose sur de nouvelles estimations...

Problems of Method in Levi-Civita’s Contributions to Hydrodynamics

Pietro Nastasi, Rossana Tazzioli (2006)

Revue d'histoire des mathématiques

Levi-Civita made important contributions to hydrodynamics: he solved D’Alembert’s paradox, introduced the “wake hypothesis”, deduced the general integral of any plane motion involving a wake, and gave a rigorous proof of the existence of the irrotational wave in a canal of finite depth. In this paper, we investigate Levi-Civita’s results in this area, and connect them to the methods of the new theory of integral equations. Finally, we give some information on Levi-Civita’s students. In our paper,...

Processi di filtrazione in un mezzo poroso con interazioni fra il liquido e la matrice porosa

F. Talamucci (2001)

Bollettino dell'Unione Matematica Italiana

A model of filtration in a multispecies porous medium accompanied by a strong interaction between the flow and the porous matrix is presented. The species removed by the flow are both fine particles and other substances which diffuse in the liquid. The accumulation of the migrating particles in proximity of the outflow surface gives rise to the formation of a compact layer with high hydraulic resistance. The corresponding mathematical model consists in a set of partial differential equations of...

Profile decomposition for solutions of the Navier-Stokes equations

Isabelle Gallagher (2001)

Bulletin de la Société Mathématique de France

We consider sequences of solutions of the Navier-Stokes equations in  ℝ 3 , associated with sequences of initial data bounded in  H ˙ 1 / 2 . We prove, in the spirit of the work of H.Bahouri and P.Gérard (in the case of the wave equation), that they can be decomposed into a sum of orthogonal profiles, bounded in  H ˙ 1 / 2 , up to a remainder term small in  L 3 ; the method is based on the proof of a similar result for the heat equation, followed by a perturbation–type argument. If  𝒜 is an “admissible” space (in particular ...

Proof of the double bubble conjecture.

Hutchings, Michael, Morgan, Frank, Ritoré, Manuel, Ros, Antonio (2000)

Electronic Research Announcements of the American Mathematical Society [electronic only]

Propagation of chaos for the 2D viscous vortex model

Nicolas Fournier, Maxime Hauray, Stéphane Mischler (2014)

Journal of the European Mathematical Society

We consider a stochastic system of N particles, usually called vortices in that setting, approximating the 2D Navier-Stokes equation written in vorticity. Assuming that the initial distribution of the position and circulation of the vortices has finite (partial) entropy and a finite moment of positive order, we show that the empirical measure of the particle system converges in law to the unique (under suitable a priori estimates) solution of the 2D Navier-Stokes equation. We actually prove a slightly...

Currently displaying 41 – 60 of 68