The Discharge Coffecient for Shaft Spillway According to Inlet Shape and Tail Water Conditions
DOI:
https://doi.org/10.14738/aivp.115.15756Keywords:
vertical spillway, flow regime, tail water, flow state, discharge coefficientAbstract
The spillway is a hydraulic facility that drains excess water or in flood by transferring it from the reservoir at the inlet of the dam to the outlet. It is considered a safety element for the dam. The type of spillway depends on several factors, including the type of dam, the topographical geological nature of the ground, the highest discharge, and the frequency of the flood wave. The vertical spillway is used in cases with a finite area to create another type of spillway. In this research, three physical intake shape models were used for vertical spillway (the circular shape C, a quadrilateral shape Q, and an octagonal shape O, with two levels of tailwater: semi and wholly submerged state, and compared with free state, to study the flow behaves on the spillway. The results showed that the weir flow regime occurred in the vertical spillway intake when the ratio H/D (Head/Diameter) > 0.5, and orifice flow regime when H/D < 0.5. When the tailwater depth was wholly submerged, the water height upstream (H) was at the minimum values in the weir flow regime. The height (H) decreases when the tailwater depth is semi-submerged in the orifice flow regime. Comparison between discharge coefficient (Cd) for three intake shapes was clear; replacing intake shape (C, Q, and O) receptivity decreased Cd in the weir flow regime. On the contrary, the discharge coefficient increases at the same flow conditions in an orifice flow regime.
References
A. R. Razavi and H. Ahmadi, “Three-dimensional simulation of flow field in morning glory spillway to determine flow regimes (Case study: Haraz Dam),” Civ. Eng. J., vol. 3, no. 11, pp. 1133–1145, 2017.
E. Nohani and H. Naghshine, “EXPERIMENTAL EVALUATION OF THE ANTI-VORTEX PLATES ANGLE ON DISCHARGE COEFFICIENT FOR THE SHAFT SPILLWAY,” Int. J. Agric., vol. 3, no. 2, p. 246, 2013.
G. Christodoulou, A. Mavrommatis, and T. Papathanassiadis, “Experimental study on the effect of piers and boundary proximity on the discharge capacity of a morning glory spillway,” 2010.
J. Yang, T. Liu, A. Bottacin-Busolin, and C. Lin, “Effects of intake-entrance profiles on free-surface vortices,” J. Hydraul. Res., vol. 52, no. 4, pp. 523–531, 2014.
M. Králík, “LABSKÁ–MODEL RESEARCH OF SHAFT SPILLWAY,” Civ. Eng. J., no. 1, 2017.
A. BRAKENI and A. PetrovicGURYEV, “An experimental study of shaft spillway with a polygonal section,” UPB Sci. Bull. Ser. D Mech. Eng., vol. 82, no. 2, pp. 255–268, 2020.
F. Sayadzadeh, S. H. Musavi-Jahromi, H. Sedghi, and A. Khosrojerdi, “Pyramidal vortex breakers influences on the flow discharge of morning glory spillway,” Ain Shams Eng. J., vol. 11, no. 2, pp. 455–463, 2020.
F. I. Khaleel and A. Y. Mohammed, “The Effect of Dual Water Jet on Discharge Coefficient of Vertical Spillway,” Al-Rafidain Eng. J., vol. 26, no. 2, pp. 292–299, 2021.
S. Esmaelizadeh and B. Lashkar-Ara, “Using a Deflector and Crest Design to Make a Safe Spillway Operation,” 2021.
S. Talebi, G. Mahtabi, M. Karbasi, and M. Akbari, “Experimental Study of Hydraulic Properties of Flow over Vertical Shaft Spillway with Bow-Tied Shape Inlet,” Irrig. Drain. Struct. Eng. Res., vol. 22, no. 85, pp. 41–58, 2022.
M. C. Aydin and A. E. Ulu, “Numerical investigation of labyrinth-shaft spillway,” Appl. Water Sci., vol. 13, no. 4, p. 89, 2023.
H. H. Bengtson, “Sharp-Crested Weirs for Open Channel Flow Measurement,” Contin. Educ. Dev., 2011.
S. A. Jalil, B. S. Hussein, and S. A. Sarhan, “Visualization of elbow flow performance as shaft spillway,” Ain Shams Eng. J., vol. 11, no. 4, pp. 865–873, 2020.
Downloads
Published
How to Cite
Issue
Section
License
Copyright (c) 2023 Intisar A. Hady, Ahmed Y. Mohammed
This work is licensed under a Creative Commons Attribution 4.0 International License.
