INFLUENCE OF A GAP ON FLOW AROUND HORIZONTAL CYLINDER

摘要

The paper presents results of an experimental investigation of an open channel flowaround horizontal circular cylinder placed at different positions above smooth bed forcylinder Reynolds numbers in the range 2.10~3-10~4. The main attention was paid tothe detail investigation of velocity distribution along a vertical going through thecenter of the cylinder. The experiments were conducted for two flow regimes -shallow flow (when the cylinder behaves like a weir) and backwater flow (when thewater surface is practically unaffected by the presence of the cylinder). Based onmeasured velocity profiles the ratios of mean and maximal velocities through thegaps to the velocities over the cylinder were determined as well as the shearvelocities on the channel bed. The computational software Fluent was used tosimulate both types of flow over the cylinder and the results were compared with theexperimental results.