On the origin of chains of cavities in the rotating flow between cylinders

Cavitation between rotating and immobile cylinders appears in the form of a regular chain of bubbles. The bubble sizes are practically equal, as well as the distances between the bubbles and their azimuthal locations. Though such a form of cavitation has been observed in numerous experiments (in particular, in the experiments with bearings), its nature was not clarified. The presented analysis shows that breakdown of the flow axial symmetry due to displacement of the axis of one of cylinders leads to the regular wave-similar three-dimensional flow perturbations. Their “wavelength” is predetermined by the minimal gap between cylinders. Though the flow between cylinders is not curl-free, these perturbations can be determined with the use of a velocity potential.