An Numerical Investigation On Fluid Flow Past A Circular Cylinder With Splitter Plate At Low Reynolds Number

Fluid flow past a circular cylinder is a complex flow phenomenon. It contains thebasic flow structures of fluid flow past the bluff body, such as wall-shear layers,free-shear layers, vortex shedding. And because of the separation of boundary layer,there is a periodic vortex shedding behind circular cylinder in the process of fluid flowpast a circular cylinder. The vortex shedding can lead to the vibration of circularcylinder and affect the normal use, even damage the circular cylinder. In order to avoidthe vortex shedding, a thin splitter plate was placed along horizontal centerlinedownstream of the circular cylinder. Fluid flow past this circular cylinder was simulatedat Reynolds number200.Numerical simulation results indicate that, the splitter plate can weaken the vortexshedding of the circular cylinder effectively, and the effect is much better when thelength of the splitter plate is much longer. The vortex is confined to the sides of theplant stably and symmetrically and the vortex shedding behind circular cylindercompletely disappeared when the length of the splitter plate five times of the diameterof the circular cylinder. Then the flow field behind the circular cylinder change intostreamlines. The Strouhal number decreased when the length of the splitter plate wassmaller than D (D is the diameter of the circular cylinder), but it increased for L＜D＜2L(L is the length of the splitter plate).Meanwhile the drag coefficient continuouslydecreased by the plate length. When the plate length five times of the cylinder diameter,the drag coefficient changed from1.32to0.95, decrease about27.8%.Numerical simulation results indicate also that, even at low Reynolds number fluidflow past a circular cylinder has some3-dimensional characteristics.