Determination of Discharge Co-efficient of Rectangular Side Weirs

ABSTRACT

The characteristics of flow over side weirs are taken into consideration to verify the discharge coefficient for subcritical flow conditions under the assumption of constant specific energy. The main channel discharge, length of weir crest and sill height of the weir are treated as controlled variables. The discharge coefficient Cd is found to depend 011 the Upstream Froude No 171 and also on the ratio of sill height to upstream flow depth S/Yl . Simple linear regression analysis was conducted to establish the relationship of Cd with both FI and S/Yl taken separately while multiple regression analysis was conducted to establish the relationship of Cd with both FI and S/Y I taken together. Cd decreases with increase ill FI while Cd increases with increase in sr{, ratio when taken separately. When taken together, it was clearly evident that variation in Cd was largely due to S/Yl ratio while tile effect of FI was relatively negligible.