Performance Against Cavity Index and Discharge Coefficient between Broad and Sharp Crested Weirs

Authors

DOI:

https://doi.org/10.25156/ptj.v12n1y2022.pp103-107

Keywords:

CFD, Sharp crested weir, Broad crested weir, Cavity index, , Discharge coefficient

Abstract

The purpose of this research is examining the performance of rectangular broad and sharp crested weirs in terms of cavity index and discharge coefficient. For this purpose, a computational fluid dynamics CFD code FLUENT is applied. Firstly, the code verified by applies on the experiments work of Hagre et al 1994 the results show excellent agreements between CFD and Hager et al 1994. Secondly the code applied on both broad and sharp crested weirs. The results demonstrate that broad crested weirs have a lower discharge coefficient than sharp crested weirs, implying that broad crested weirs have a lower ability to discharge flow than sharp crested weirs. While the cavity index of a broad crested weir is lower than that of a sharp crested weir, the risk of cavitation is lower for a broad crested weir. Finally, designers should use caution when deciding which type of crest to use in their designs.

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References

Ahmed, S.S. and Aziz, Y.W., 2018. Numerical Modeling of Flow in Side Channel Spillway Using ANSYS-CFX. Zanco Journal of Pure and Applied Sciences, 30(1), pp.83-93.

Falvey, H. T. (1990). Cavitation in chutes and spillways. Engineering Monograph 42. Water Resources Technical Publication. US Printing Office. Bureau of Reclamation. Denver.‏

Frizell, K. H. & Mefford, B. W. (1991) 'Designing spillways to prevent cavitation

damage'. Concrete International, 13 (5). pp 58-64.'

Frizell, K.W. and Renna, F.M., 2011. Laboratory studies on the cavitation potential of stepped spillways. Apelt, CJ (Editor); Ball, J (Editor), pp.2420-2427.

Felder, S. and Chanson, H., 2012. Free-surface profiles, velocity and pressure distributions on a broad-crested weir: A physical study. Journal of Irrigation and Drainage Engineering, 138(12), pp.1068-1074.

French, R.H. and French, R.H., 1985. Open-channel hydraulics (p. 705). New York: McGraw-Hill.

Hager, W.H. and Schwalt, M., 1994. Broad-crested weir. Journal of irrigation and drainage engineering, 120(1), pp.13-26.

Imanian, H., Mohammadian, A. and Hoshyar, P., 2021. Experimental and numerical study of flow over a broad-crested weir under different hydraulic head ratios. Flow Measurement and Instrumentation, 80, p.102004.

Montes, J. S. (1998). Hydraulics of open channel flow, ASCE, New York

Piradeepan, N., 2002. An experimental and numerical investigation of a turbulent airfoil wake in a 90° curved duct (Doctoral dissertation, Brunel University School of Engineering and Design PhD Theses).

Rao, N.G. and Muralidhar, D., 1963. Discharge characteristics of weirs of finite-crest width. La Houille Blanche, (5), pp.537-545.

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Published

2023-04-16

How to Cite

A, A. A. (2023). Performance Against Cavity Index and Discharge Coefficient between Broad and Sharp Crested Weirs. Polytechnic Journal, 12(1), 103-107. https://doi.org/10.25156/ptj.v12n1y2022.pp103-107

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Research Articles