DOI: 10.1615/TSFP6
VORTEX SHEDDING FROM A STEP-CYLINDER IN SHEAR FLOW
要約
Vortex shedding patterns behind a step-cylinder in uniformly shear flow for Reynolds numbers between 152 and 674 were studied using flow visualization and laser Doppler velocimetry. The results were analyzed using spectral analysis and the wavelet transform. The effect of shearing on vortex shedding was found to be significant. As in uniform flow, the step-change in diameter caused the formation of a distinct near-step vortex cell behind the large cylinder, with frequency lower than those in both neighbouring cells. Shearing affected both the spanwise length of this cell and the difference between its frequency and that in the adjacent large-cylinder cell. The values of these parameters were found to depend both on the Reynolds number and the orientation of the cylinder axis relative to the shear direction.