Measurement of fluid velocity development behind a circular cylinder using particle image velocimetry (PIV)

In this paper we present a non-intrusive experimental approach for obtaining a two-dimensional velocity distribution around a 22 mm diameter circular cylinder mounted in a water tunnel. Measurements were performed for a constant Reynolds number of 7670 using a commercial standard particle image velocimetry (PIV) system. Different flow patterns generated behind the circular cylinder are discussed. Both instantaneous and time-averaged velocity distributions with corresponding streamlines are obtained. Key concepts in fluid mechanics, such as contra-rotating vortices, von Karman vortex street, and laminar-turbulent flow, are discussed. In addition, brief historical information pertaining to the development of flow measurement techniques-in particular, PIV-is described.