Experimental Analysis of the Strato-Rotational Instability in a cylindrical Couette flow

Michael Le Bars (1) , Patrice Le Gal (1)

1 IRPHE - Institut de Recherche sur les Phénomènes Hors Equilibre

This study is devoted to the experimental analysis of the Strato-rotational Instability (SRI). This instability affects the classical cylindrical Couette flow when the fluid is stably stratified in the axial direction. In agreement with recent theoretical and numerical analyses, we describe for the first time in detail the destabilization of the stratified flow below the Rayleigh line (i.e. the stability threshold without stratification). We confirm that the unstable modes of the SRI are non axisymmetric, oscillatory, and take place as soon as the azimuthal linear velocity decreases along the radial direction. This new instability is relevant for accretion disks.

Mots clés: Strato-Rotational Instability; stratified fluid; Couette flow; accretion disks

Domaines: Dynamique des Fluides [physics.flu-dyn]

Michael Le Bars, Patrice Le Gal. Experimental Analysis of the Strato-Rotational Instability in a cylindrical Couette flow. Physical Review Letters, 2007, 99, pp.064502. ⟨10.1103/PhysRevLett.99.064502⟩. ⟨hal-00157389⟩