TRANSITION FOR DESILTING BASIN WITH OPEN CHANNEL FLOW

Desilting basin forms an integral part of the water conductor system of run-of-the- river schemes for hydro power generation while suspended sediment concentration is very high during monsoon. Transitions are provided to gradually reduce the velocity of flow entering into the basin. If transition is too long there is deposition of medium and coarse sediment on the bed of the transition itself. If transition is too short, there is uneven distribution of flow and higher turbulence. As such optimization of transition length, shape and bed slope is necessary to avoid deposition on the transition bed and more or less uniform distribution of flow entering into the desilting basin. As far open channel desilting basin is concerned inlet transition is very difficult to design due to substantial difference in depths on upstream and downstream of transition and also due to sub critical expansion. This objective could be achieved by providing a simple hump. The results of the hydraulic model studies conducte...