ABSTRACT
ABSTRACT: Numerical models were built to investigate the effects of flow depth on open flow over a horizontal cylinder. Results show the abrupt change of flow surface at the cylinder, backup at the upstream side and drawdown at the downstream side. The center of drawdown curve is somewhere downstream of the cylinder center, which coincides with previous experimental results. With the decrement of flow depth, the drawdown effect becomes more and more obvious. Compared with the inlet velocity, flow beneath and downstream of the cylinder accelerates. The maximum bed shear stress shows up under the cylinder. The bed shear stress goes up with the flow depth, but the climbing rate slows down. The pressure on the bed increases with the flow depth. The pressure difference upstream and downstream the cylinder decreases with the decrement of flow depth.
