Search results for " Rectangular weir"
showing 3 items of 3 documents
Experimental study and numerical simulation of inclined rectangular weirs
2018
Inclined rectangular weirs, also named pivot weirs, are used both to adjust the upstream water level and to increase the flow capacity compared with that of normal rectangular weirs. However, the experimental studies available in the literature present contradictory conclusions for the inclined weir discharge capacity. In this paper, new experimental runs and numerical simulations were performed to investigate the effect of the rectangular weir inclination angle on the stage-discharge formula. The experiments were carried out using inclination angles ranging from 30° to 90°. Buckingham's theorem of dimensional analysis was used to obtain an equation for the flow magnification ratio (the dis…
Generalised stage-discharge relationship for rectangular weirs
2018
Rectangular weirs, which are very common hydraulic structures used in irrigation channels as water measuring devices, can be used for measuring very small discharges as well as high flow rates. From the practical point of view the availability of a unique stage-discharge formula that can be applied for the different types of the rectangular weirs would be of great practical importance. At first, in this paper the Buckingham’s Theorem of the dimensional analysis and the self-similarity theory are used to deduce the stage-discharge curve of different kinds of rectangular weirs such as slit and partially contracted ones. Then the proposed formula is calibrated using both the experimental data …
Deducing the stage-discharge relationship for contracted weirs by the outflow theory of Malcherek
2019
The aim of this paper was the deduction of a new stage-discharge relationship for a contracted weir, having a crest length less than the channel width, by using the Malcherek’s outflow theory. The average outflow velocity over the rectangular contracted weir was expressed in terms of the head over weir, the momentum correction coefficient and the ratio between the crest length and the channel width. This theoretically deduced stage-discharge formula was calibrated by measurements carried out for values of the ratio between the crest length and the channel width ranging from 0.3125 to 0.9375. In particular, a relationship to estimate the momentum correction coefficient for contracted weirs w…