DISCHARGE CHARACTERISTICS OF WEIRS

Abstract

weirs as a part of irrig ation structures have been in use for the measurement of discharge for a number of years. Despite many efforts for the past two decades, a rational and general solution for the problem of discharge characteristics of weirs has not been established. Investigations in this connection have been carried out by mathematicians, scientists and engineers. Most of the investigators have proposed solutions which reflect merely their individual method of approach and are related chief-ly to special and rather limited conditions. An attempt has been made to pool out the important available literature on the dis-charge characteristics of weirs both under free-flow and sub-mergence conditions. Emphasis is laid upon common types of weirs used in practice, viz.. thin-plate, , broom- crested, trapezoidal, triangular, and ogee weirs. In addition, the experimental findings of the author on (i) trapezoidal weir with upstream face vertical (upstream cor-ner rounded) and downstream sloping at 0.7-to-1 for different crest widths, and (ii) triangular weir with different upstream and downstream slopes, have also been presented. The author's results are different from those contained in the formula sugg-ested by Govinda Rao and Muralidhar for evaluation of co-effi-cient of discharge for triangular weirs. Making use of the data of investigators presented in this dissertation, it is possible to'evaluate the co-efficient of disc harge cf triangular weir of different slopes to a fair degree of reliance..