A new path to the non blow-up of incompressible flows

Léo Agélas (1)

1 IFPEN - IFP Energies nouvelles

One of the most challenging questions in fluid dynamics is whether the threedimensional (3D) incompressible Navier-Stokes, 3D Euler and two-dimensional Quasi-Geostrophic (2D QG) equations can develop a finite-time singularity from smooth initial data. Recently, from a numerical point of view, Luo & Hou presented a class of potentially singular solutions to the Euler equations in a fluid with solid boundary Luo and Hou (2014a,b). Furthermore, in two recent papers Tao (2016a,b), Tao indicates a significant barrier to establishing global regularity for the 3D Euler and Navier-Stokes equations, in that any method for achieving this, must use the finer geometric structure of these equations. In this paper, we show that the singularity discovered by Luo & Hou which lies right on the boundary is not relevant in the case of the whole domain R3. We reveal also that the translation and rotation invariance present in the Euler, Navier-Stokes and 2D QG equations are the key for the non blow-up in finite time of the solutions. The translation and rotation invariance of these equations combined with the anisotropic structure of regions of high vorticity allowed to establish a new geometric non blow-up criterion which yield us to the non blow-up of the solutions in all the Kerr’s numerical experiments and to show that the potential mechanism of blow-up introduced in Brenner et al. (2016) cannot lead to the blow-up in finite time of solutions of Euler equations.

Mots clés: 3D Navier-Stokes equations; 2D Quasi-Geostrophic equation; 3D Euler equations; Finite time singularities; Geometric properties for non blow-up

Domaines: Equations aux dérivées partielles [math.AP]; Dynamique des Fluides [physics.flu-dyn]

Léo Agélas. A new path to the non blow-up of incompressible flows. 2018. ⟨hal-01380349v4⟩