Experimental study of the multipolar vortex instability
The instability of a vortex subjected to a stationary dipolar or tripolar constraint is studied experimentally by using a rotating deformable cylinder on which two or three rollers are applied. As the Reynolds number and the aspect ratio of the cylinder are varied, different modes of instability are observed and their wavelength and frequency are compared to theoretical predictions. Secondary instability and cyclic breakup are also evidenced in the elliptic geometry.
Eloy
C
Institut de Recherche sur les Phenomenes Hors Equilibre, CNRS UMR 6594, Marseille, France.
Le Gal P
Le Dizes S