A survey is conducted to quantitatively visualise the wake flow behind a circular cylinder at Reynolds numbers of 180 to 2500. A time-resolved tomographic PIV method is used to measure the sequence of three-dimensional vector fields evolving in time. The attention is focused upon the unsteady 3D wake organization with the interaction of primary rollers (Karman-Benard) and the secondary vortices resulting from 3D instability of the vortex wake. 體視層析粒子成像測速系統(tǒng)(Tomo-PIV) HighSpeedStar PIV相機(jī) 用于粒子成像測速(PIV)的熒光示蹤粒子