Viscous Type Instability of the Boundary Layer on a Rotating Disk

Abstract

The characteristics of the viscous type instability of the boundary layer flow on a rotating disk in a still fluid are investigated in detail by means of a linear stability analysis. The critical Reynolds number for the viscous type instability is found to be 55.5. The phase speed, wave number and wave front orientation are also calculated. The results are compared with those for inviscid type instability. The viscous type instability is visualized experimentally for the first time.