Vortex shedding from a two-dimensional blunt trailing edge with unequal external free-stream velocities

The properties of vortex shedding from a blunt trailing edge of a plate was experimentally investigated for unequal free-stream velocities, a Reynolds number range between about 190 and 3000, and a low-to-high velocity ratio K from 0 to 1.0. Experiments were performed in a recirculating water channel with a rectangular test section. The center of the plate coincided with the center of the channel. The frequency of vortex shedding was determined on the basis of the power spectra of the velocity fluctuations in the wake of the plate. It was found that for K of 0.78 or more, the relation between Strouhal number and Reynolds number was almost the same as that when K was unity. The Strouhal number was higher for K less than 0.78 than for K greater than 0.78. The critical Re beyond which vortex shedding occurred was obtained as a function of Re and K.