Investigation on Vortex Shedding and Noise control of Flow around Cylinder by Blowing and Suction

In this paper, the effect of vortex shedding and noise control by air blowing and suction through circumferential hole on a circular cylinder is studied by numerical simulation. Two reduced-order methods: Proper Orthogonal Decomposition (POD) and Dynamic Mode Decomposition (DMD) are employed to identify the potential mechanism of flow control by air blowing and suction. The results show: 1) Compared with blowing, air suction has a better effect on vortex shedding and noise control. The highest amount of noise reduction can achieve in 37.7dB and the vortex shedding is greatly suppressed at this time. 2) Through POD and DMD, it is found that air suction achieves the effect of reducing drag by decreasing the modes energy proportion related to drag. The stability of the flow field is improved by air suction, which leads the reduction of the flow-induced noise.