Experimental study of slit cylinder vortex shedding in circulating water channel

This paper mainly researched the influence of slit-vent modification on the flow field variation of a circular cylinder´s wake flow and the modulating effect on vortex shedding frequency. Experiment contents contained qualitative flow visualization and quantitative measurements. A huge amount of PIV data was acquired and evaluated to obtain the instantaneous flow structure as well as the time-averaged feature of wake flow past both slit circular cylinder and baseline circular cylinder. Meanwhile, complete periodical evolution of vortex generation and shedding in the near wake flow was analyzed, and the vortex shedding frequency alteration under different water channel speeds was also studied. The results of flow visualization revealed that, the vortex shedding frequency of slit cylinder was faster than baseline cylinder. It demonstrated that the slit structure of cylinder enhanced the intension of wake flow variation.