VORTEX SHEDDING CONTROLLED BY THE TRANSVERSE VIBRATION OF 3 IN-LINE ELLIPTIC CYLINDERS IN A UNIFORM-FLOW

An experimental study has been conducted on the vortex shedding frequency from three in-line elliptic cylinders with one of them undergoing forced transverse vibration in a uniform now at frequencies up to 4 times the natural vortex shedding frequency. The possibility that the vortex shedding from each elliptic cylinder can be controlled by the vibrating cylinder is examined by FFT analyses. It is shown that the locking-on characteristics of each cylinder depend on the arrangement of the elliptic cylinders, the amplitude and frequency of forced vibration, the uniform flow Reynolds number and the location of the vibrating cylinder.