FLOW CHARACTERISTICS OF CHIMNEY WEIR UNDER SUBMERGENCE

A theoretical submerged flow equation for chimney weir is developed. B ased on experiments conducted with five different chimney weirs, it is found that the theoretical submerged how equation, along with a parab olic equation relating the coefficient of discharge and the ratio of u pstream head to crest height, predicts the discharge accurately. The p erformance of the developed equation is compared with the previously d eveloped submergence formulas for sharp-crested weirs, and it is seen that the developed equation performs better within the experimental ra nge. Further, for simplicity, an empirical equation is also proposed, which is found to give reasonable prediction of submerged discharge.