Orateur
Émile Deléage
(Aix-Marseille Université)
Description
We present a class of hyperbolic systems modeling two-phase, two-velocity flows that can be obtained from Hamilton's principle of stationary action. The hyperbolicity is guaranteed for small relative velocities by the presence of turbulence through a Reynolds stress tensor. Various forms of the turbulent term are proposed, and the ones leading to a hyperbolic system of equations are characterized by a general criterion. The presence of the Reynolds stress tensor is crucial for the hyperbolicity. Indeed, if it is removed from the Lagrangian, the resulting equations are not hyperbolic for small relative velocities.
