Three-dimensional flow characteristics near a circular cylinder mounted on horizontal plate at low Reynolds number

摘要

Flow field characteristics in the neighbourhood of a finite height circular cylinder mounted on a horizontal plate have been investigated numerically. Three-dimensional simulations are carried out for low Reynolds number (Re) incompressible flow using commercial software ANSYS Fluent 14.0. Topological characteristics of the flow have been investigated near the cylinder of aspect ratio (AR) ranging from 0.5 to 3.0 with Re varied in the range from 40 to 300. Time-averaged streamline plots are presented in various planes for different values of AR and Re to understand the flow field characteristics. For a developing flow impinging on the cylinder, flow separation in upstream of cylinder close to the cylinder-bottom wall junction leads to horseshoe vortex formation. Various topological characteristics like saddle, node have been identified in upstream and downstream of the cylinder. Positions of saddles are shown to depend on the values of AR and Re. Development of recirculation region and formations of vortex bubble have been studied in form of their projections on different planes. The variation of mean drag coefficient on the cylinder with Re for different values of AR has also been presented.