STUDY OF FLOW CHARACTRISTICS AROUND A CIRCULAR CYLINDER NEAR PLANE BOUNDARY

Flow around circular cylinders near plane boundary has been a subject of interest because of vast practical engineering applications such as offshore pipelines nearseabed. Vortex shedding phenomenon leads to vortex induced vibration of a cylinder subjected to both inline and cross flow, which is undesirable due to fatigue concerns. In order to control or suppress vortex shedding an adequate knowledge of flow characteristics around a circular cylinder based on reliable quantitative parameters andvisualized outputs is necessary. The flow characteristics around a circular cylinder near plane was has been studied using Open source CFD codes of OpenFOAM in different flow regimes (Re=100, 200, 3900) and different gap ratios (G/D=∞, 1, 0.5, 0.2). According to results, occurrence of vortex shedding suppression can be determined based on a combination of plane wall effect and flow regime parameters such as gap to boundary layer thickness ratio. Also Pressure distribution around cylinder surface and separation angle of vortices can be observed as further implication of the process of suppression. Some of near wall flow field parameters around circular cylinder has been illustrated in figure 1.