Краткое описание

Our previous study revealed the occurrence of flip-flop phenomena in the exit streams from diamond-shaped cylinder bundles, something that has never been observed in circular cylinder bundles. This motivates us to investigate the basic difference in wake flows behind single-square (a special diamond-shaped quadruple) and circular cylinders. Two kinds of experiments were performed: flow visualization and two-dimensional laser Doppler velocimetry (LDV). The former yields flow patterns by means of a fluorescence dye injection illuminated by a laser light sheet. The LDV experiment produces velocity vector distributions, from which the distribution of vorticity, turbulence intensity, and Reynolds stress can be derived.