Abstract
In the present study, we investigate a self-excited oscillatory phenomenon of a two-dimensional confined jet with a rectangular-cross-section cylinder as a downstream target. More specifically, in order to reveal the effects of a streamwise size a of the downstream target upon both the occurrence condition for stable jet's oscillation and the jet-oscillation frequency fp, we conduct experiments at Re = 500 in water by an ultrasonic velocity profiler. As a result, we find that the effect the non-dimensional streamwise target size a/b upon the occurrence condition is negligible at alb > 10, where b denotes a length scale of the jet's breadth At alb > 10, we cannot ignore the a/b effect, namely, the jet's oscillation tends to suppress. However, if we can detectfp,fp can be predicted welly by the proposed empirical formula describing the relation of St with the four geometric parameters.
