Discharge coefficient equation to calculate the leakage from pipe networks

Yıl 2020, Cilt: 10 Sayı: 3, 1737 - 1746, 01.09.2020

Ömer Ekmekcioğlu , Eyyup Ensar Başakın , Mehmet Özger

https://doi.org/10.21597/jist.675015

Cited By: 2

Öz

With the increasing of urbanization, water distribution networks play an important role in human life and the effective use of water resources. Therefore, studies have been made for the optimization of water distribution networks in some fields such as pressure management and leakage control. In this context, the discharge coefficient, which is one of the components of the hydraulic calculations, is a very significant parameter in calculating the losses. In this study, a new equation has been proposed to calculate the discharge coefficient. Computer simulations were done by using ANSYS Fluent and discharge coefficient values were determined for round holes. Firstly, the model validated with theoretical Toricelli (orifice) equation and then, the model was run for number of scenarios according to various internal pressure and hole areas. The model results were formulated by means of regression equations. To satisfy the dimensional homogeneity, the ratio of the hole area to the pipe cross-sectional area, area ratio (r), and the ratio of the internal pressure to the external pressure, pressure ratio (p), were used. In this study, easy to use discharge coefficient equation was proposed to calculate the leakage losses in water distribution networks. With the help of this equation, the discharge coefficient can be calculated precisely for different pressure values and leakage areas rather thantaken as a constant value. Thus, the calculation of the leakage flow rate will be more accurate. Furthermore, it is concluded that the dicharge coefficient varies between 0.65 and 0.72. There is also inverse realtionship between discharge coefficient and pressure and discharge coefficient and leakage area.

Anahtar Kelimeler

water distribution network, discharge coefficient, leakage, orifice

Kaynakça

• Butterfield JD, Meyers G, Meruane V, Collins RP, Beck SBM, 2018. Experimental investigation into techniques to predict leak shapes in water distribution systems using vibration measurements. Journal of Hydroinformatics 20 (4): 815-828.
• Cassa AM, Van Zyl JE, 2013. Predicting the head-leakage slope of cracks in pipes subject to elastic deformations. Journal of Water Supply Research and Technology – AQUA 62(4), 214–223.
• Cassa AM, van Zyl JE, Laubscher RF, 2010. A numerical investigation into the effect of pressure on holes and cracks in water supply pipes. Urban Water Journal 7(2), 109–120.
• De Marchis M, Fontanazza CM, Freni G, Notaro V, Puleo V, 2016. Experimental evidence of leaks in elastic pipes. Water Resources Management 30(6), 2005–2019.
• Fontana N, Giugni M, Glielmo L, Marini G, and Verrilli F, 2017. A Lab Prototype of Pressure Control in Water Distribution Networks. IFAC-PapersOnLine 50 (1), 15373–15378.
• Fox S, Collins R, Boxall J, 2016. Experimental study exploring the interaction of structural and leakage dynamics. Journal of Hydraulic Engineering 143(2), 04016080.
• Fox S, Collins R, Boxall J, 2017. Physical investigation into the significance of ground conditions on dynamic leakage behaviour. Journal of Water Supply Research and Technology 65(2), 103–115.
• Germanopoulos G, 1985. A technical note on the inclusion of pressure dependent demand and leakage terms in water supply network models. Civil Engineering Systems 2(3), 171–179.
• Greyvenstein B, van Zyl JE, 2007. An experimental investigation into the pressure-leakage relationship of some failed water pipes. Journal of Water Supply Research and Technology –AQUA 56(2), 117-124.
• Idelchik E, 2003. Handbook of hydraulic resistance (2nd revised and enlarged edition): Washington.
• Kabaasha M, Piller O, van Zyl JE, 2018. Incorporating the Modified Orifice Equation into Pipe Network Solvers for More Realistic Leakage Modeling. Journal of Hydraulic Engineering 144(2): 04017064.
• Lambert AO, 2001. What do we know about pressure: leakage relationships in distribution systems? IWA Conference System Approach to Leakage Control and Water Distribution Systems Management, 1–9.
• Lydon T, Coughlan P, McNabola A, 2017. Pressure management and energy recovery in water distribution networks: Development of design and selection methodologies using three pump-as-turbine case studies. Renewable Energy 114:1038–1050.
• May J, 1994. Pressure dependent leakage. World Water & Environmental Engineering. http://www.leakssuite.com/wpcontent/uploads/2016/10/JOHN-MAYSEMINAL-1994 ARTICLE-4.pdf.
• Monsef H, Naghashzadegan M, Farmani R, Jamali A, 2018. Pressure management in water distribution systems in order to reduce energy consumption and background leakage. Journal of Water Supply Research and Technology 67 (4): 397-403.
• Nsanzubuhoro R , van Zyl JE, Zingoni A, 2017. Predicting the head-area slopes of circular holes in water pipes. Procedia Engineering (186), 110 – 116.
• Samir N, Kansoh R, Elbarki W, Fleifle A, 2017. Pressure control for minimizing leakage in water distribution systems. Alexandria Engineering Journal 56:601–612.
• Schwaller J, Van Zyl JE, 2014. Modeling the Pressure-Leakage Response of Water Distribution Systems Based on individual leak behavior. Journal of Hydraulic Engineering 141(5), 04014089.
• Ssozi EN, Reddy BD, Van Zyl JE, 2015. Numerical investigation of the influence of viscoelastic deformation on the pressure-leakage behavior of plastic pipe. Journal of Hydraulic Engineering 142(3), 04015057.
• Sturm R, Thornton J, 2005. Proactive Leakage Management Using District Metered Areas (DMA) and Pressure Management–Is It Applicable in North America. IWA Leakage 2005 Conference Proceedings, 1–13.
• Thornton J, Lambert AO, 2007. Pressure Management Extends Infrastructure Life and Reduces Unnecessary Energy Costs. Proceedings of the IWA International Specialised Conference Water Loss 2007, 1–10.
• Van Zyl JE, Clayton CRI, 2017. The effect of pressure on leakage in water distribution systems. Proceedings of the Institution of Civil Engineers - Water Management.
• Van Zyl JE, Lambert AO, Collins R, 2017. Realistic Modeling of Leakage and Intrusion Flows through Leak Openings in Pipes. Journal of Hydraulic Engineering 143(9): 04017030.
• Van Zyl JE, Malde R, 2017. Evaluating the pressure-leakage behaviour of leaks in water pipes. Journal of Water Supply Research and Technology – AQUA, 136, 66:287–299.
• Walski T, Bezts W, Posluszny ET, Weir M, Whitman BE, 2006. Modeling leakage reduction through pressure control, Journal of American Water Works Association 98(4), 147–155.
• Walski T, Whitman B, Baron M, Gerloff F, 2009. Pressure vs. flow relationship for pipe leaks. World Environmental and Water Resources Congress 2009, 342, 1–10.
• Xu Q, Chen Q, Ma J, Blanckaert K, Wan Z, 2014. Water Saving and Energy Reduction through Pressure Management in Urban Water Distribution Networks. Water Resources Management 28 (11): 3715–3726.