Standing wave at dropshaft inlets

Standing waves occur frequently at the inlet due to the change of the flow direction from an approach channel to the drop-shaft. The performance of the standing wave, characterized by the relative height, the location and the extent, is theoretically and experimentally investigated in the present paper. It is shown that the height of the standing wave decreases with the increases of the approach flow Froude number and the sub-channel number in the inlet, but increases with the increase of the curvature of the dropshaft. The errors of the expressions for the relative height, the location and the extent of the standing wave, are 9.7%, 7.8% and 13.1%, respectively, as compared with the experimental data.