Systematic material and crack type specific pipe burst outflow simulations by means of EPANET2

Abstract

The calculation of outflow from pipe bursts is of interest for water utilities, as the discharged water may cause large amounts of damage to the adjacent infrastructure. Therefore, the crack type specific relationship between leakage outflow and pressure is of interest. Recent findings offer new opportunities for burst outflow calculations with hydraulic models. In this paper, we compare two calculation approaches according to uncertainties caused by input parameters and give recommendations for the applicability of the methods. Simulations in a case study area have shown large leakage outflow differences between the two approaches for longitudinal cracks. For circumferential cracks, the differences are smaller. Further, due to the uncertain leak size and form of probable bursts we involved Monte Carlo simulations in the model approach. These allow the derivation of mean values and standard deviations of leakage outflow per pipe section to make the uncertainty of the results more transparent.

Performance optimization of unplanned water distribution networks in fast growing towns: a case study of Mwanza city, Tanzania

“…Van (2007) demonstrated the outshot of flow exponent on the leakage flow rate, as indicated in Fig 10 . When the pressure at the leakage point is reduced by half, then the flow exponent 0.5, 1.0, and 2.5 will be reduced by 29%, 50% and 82% respectively, where H is the values of pressure at the leakage points and q is the leakage flow rate. As per Hanusch et al (2007), the flow exponent for cast iron pipes was 0.85; for PE was 1.5 and 0.9 for asbestos. The discharge coefficient of different networks varies depending on the geometry of orifices area, including pipe materials, leak openings, and pressure head.…”