Analytical Approach for Flow over an Oblique Weir

• Published in: Scientia Iranica Transaction A: Civil Engineering Vol. 17; no. 2; pp. 107 - 117
• Main Author: Kabiri-Samani, A R
• Format: Journal Article
• Language: English
• Published: 01.04.2010
• Subjects: Angles (geometry); Calibration; Channels; Computational fluid dynamics; Continuity equation; Discharge; Discharge coefficients; Flow deflection; Fluid flow; Guide vanes; Hydraulics; Mathematical analysis; Performance enhancement; Submerged
• ISSN: 1026-3098

Flow discharge over an oblique weir is greater than that over a straight or plain weir for the same water head due to its extra length with respect to the channel width or fully extended plain weir. In this study, a new theoretical approach is used for the hydraulics of oblique weirs. The main objective is to investigate the effect of different hydraulic and geometric properties of the flow and the weir on the flow deflection angle and discharge coefficients for free and submerged flow over oblique weirs. This approach is based on energy, momentum and continuity equations. For improving the performance of this kind of weir, one approach is to increase the flow deflection until it is perpendicular to the oblique weir for maximum use of the weir length. The submerged guide vanes have also been used and investigated theoretically. The data for calibration of the models are taken from Borghei et al. (2003). It is shown that by employing guide vanes, for some cases, the discharge coefficient can be increased up to 33%. Finally, new relations were developed for practical purposes.