Abstract
The effect of constriction ratio β at a stenosed on vortex ring behavior, which was induced by a sinusoidal pulsatile jet flow downstream of stenosed was studied experimentally by means of PTV methods. Phase mean velocity vectors in the downstream region of stenosed model were measured under the condition of β=0.33 and 0.50. It was observed that, in both β conditions, vortex ring was produced during the period of increase in flow rate and was propagated downstream with constant velocity. In the case of β=0.50, the second vortex ring was produced in contiguity with the leading vortex ring, but in the case of β=0.33, it was observed only higher St number, in the case of β=0.33 the vortex ring breakdown was followed during a period. In the case of β=0.50, however, the vortex ring kept propagating with during a few periods.
