Behavior of Vortex Ring induced by Pulsatile Jet in a Stenosed Tube

Abstract

The effect of pulsatile flow conditions on vortex behavior downstream of stenosed was studied by means of PTV methods. Phase mean velocity vectors were measured, in the region downstream of stenosed model with 89% area reduction, under the condition of sinusoidal pulsatile flow of mean Reynolds number Re=100∿300 and Stokes number St=151∿410. In each condition, vortex ring were induced by jet flow behind the stenosed, during the period of increase in flow rate. Vortex rings were propagated downstream with constant velocity, and breakdown were followed. The breakdown position of vortex ring were changed depend on St number but independent of Re number. The ratio of propagation velocity of vortex ring and mean velocity in a period at the stenosed was changed also depend on St number but independent of Re number.