Accession Number : AD0711831

Title :   AN EXPERIMENTAL INVESTIGATION OF THE VORTEX-BREAKDOWN PHENOMENON,

Corporate Author : NAVAL POSTGRADUATE SCHOOL MONTEREY CALIF

Personal Author(s) : Sarpkaya,Turgut

Report Date : 30 JUL 1970

Pagination or Media Count : 66

Abstract : The results of an experimental investigation of the characteristics of stationary and travelling vortex breakdowns in swirling flow in a diverging cylindrical tube are presented and discussed. Basically, three types of vortex breakdown were observed, viz., double helix, spiral, and axisymmetric breakdown. The type and location of the stationary breakdowns were found to be dependent upon the Reynolds and circulation numbers of the flow. The breakdown bubble responded to gradual and abrupt changes in the upstream and downstream flow conditions in a manner analogous to the hydraulic jump in open-channel flow. The observations reported and the evidence presented revealed unmistakably that the vortex breakdown is a finite transition from a uniform state of swirling flow (supercritical) to one (subcritical) featuring a large standing wave, followed by standing wavelets, of finite amplitude. (Author)

Descriptors :   (*VORTICES, DEGRADATION), CYLINDRICAL BODIES, REYNOLDS NUMBER

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE