Incorporating the Modified Orifice Equation into Pipe Network Solvers for More Realistic Leakage Modeling
Publication: Journal of Hydraulic Engineering
Volume 144, Issue 2
Abstract
It has been well established in several experimental and modeling studies that leak areas are often not fixed, but vary as linear functions of pressure. Replacing this linear equation into the orifice equation results in a two-part modified orifice leakage equation with head exponents of 0.5 and 1.5. The purpose of this study was to incorporate the modified orifice equation into the hydraulic network formulation and evaluate its impact on model performance. The conventional and modified software were applied to 600 instances of stochastic leakage distributions in three different pipe networks. It was found that the conventional power leakage equation results in significant leakage volume and flow-rate errors under certain conditions. In addition, a problem of nonconvergence of the conventional global gradient algorithm for leakage exponents greater than 2 was observed and is discussed.
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Acknowledgments
The authors would like to express their appreciation to Mr. Simon Scruton and his team at the eThekwini Water and Sanitation unit, for providing water-distribution network model of the central business district of Durban, from which the large network was adapted.
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Published In
Journal of Hydraulic Engineering
Volume 144 • Issue 2 • February 2018
Copyright
©2017 American Society of Civil Engineers.
History
Received: Dec 29, 2016
Accepted: Jul 31, 2017
Published online: Dec 6, 2017
Published in print: Feb 1, 2018
Discussion open until: May 6, 2018
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