Abstract
The energy loss at manholes in a storm sewer network is often compared with the friction loss in pipes under surcharge flow. Especially the energy loss at three-way manholes under road crossings is much large due to collision of flows from upstream pipes and occurrence of large-scale vortices in the manholes. Some researchers have already investigated the energy loss at three-way manholes. However, the relationship between the energy loss and the water depth in manholes has not been studied yet. In this study, the effect of water depth on energy loss at a three-way circular manhole was examined. Experimental results indicated that the loss coefficient on the main pipes and the lateral pipe was influenced by water depth in the manhole and the ratio of the flow rates in the lateral and in the downstream pipes.
