ANALYSIS OF FLOW OVER SUPPRESSED AND, CONTRACTED BROAD CRESTED WEIR

Abstract

This thesis presents the results of an o erimcntal investigation for predicting the discharge over supproesod and contr ctod broad erot3 oars. The study is restricted to v ol.rs h ,vin g vortical upstream and downstream;i st rea faces and ho roflu tal crests. The onargy and continuity otuat.tons have boon used to obtain rel tion for the dis hargo coeffi cIent In termo of the geometry of flow of the weir. This has bofln usod subsenuontly In analysing exertmcntal data to study tho Influence of fluid viscosity and the friction offered the cro9t. The o,rlmcn tat data analysed includo thaso collected by earlier Investi gators as well as those collected the author. Zt has been ahot that the ratio of effective head over the weir to the measured hoed is related to tho ratio /A, for a supprossed w0131 the relationship Is hoti avor shown to be different for shore edged and roundod corner weirs* In the case of contracted metre the ratio of affective width to the actual width of the welt is shown to be a function of H/t. These relations enable prediction of discharge to an accuracy of 4 for tho available data. Tho available data have also boon used to test the accuracy of the o isting discharge relation h1pg. tt he lawn found that these rolrttonships era not adequate over a wide range of v-,rtabio . some Information concerning the brink depth on a broad crested weir end the nature of the water surface profile on the crust hn0 also boon collected and nnaiy~,od.