OSCILLATION INDUCED BY THE CENTRIFUGAL FORCE IN OPEN CHANNEL FLOWS OVER CIRCULAR SURFACE

摘要

The depth-averaged equations of open channel flows based on a generalized coordinate system attached to an arbitrary 3D surface was applied to investigate the unsteady characteristics of flows over a circular surface. Laboratory tests were conducted in order to verify the model. Fluctuations were observed at the region with circular bottom. They were not the roll waves but the oscillations induced by the centrifugal force. The oscillation intensity tended to increase in the downstream direction in the circular region. The comparison of oscillation period showed the good agreement between the computational and experimental results. This proves the applicability of the model to simulate the flow oscillation, though discrepancies in term of oscillation amplitude were observed.