Flow Characteristics of Chimney Weir under Submergence

Abstract

A theoretical submerged flow equation for chimney weir is developed. Based on experiments conducted with five different chimney weirs, it is found that the theoretical submerged flow equation, along with a parabolic equation relating the coefficient of discharge and the ratio of upstream head to crest height, predicts the discharge accurately. The performance of the developed equation is compared with the previously developed submergence formulas for sharp-crested weirs, and it is seen that the developed equation performs better within the experimental range. Further, for simplicity, an empirical equation is also proposed, which is found to give reasonable prediction of submerged discharge.