Water Distribution Network Pressure-Driven Analysis Using the Enhanced Global Gradient Algorithm (EGGA)

2011 ◽  
Vol 137 (6) ◽  
pp. 498-510 ◽  
Author(s):  
Orazio Giustolisi ◽  
Daniele Laucelli
Keyword(s):  
Water Distribution ◽  
Distribution Network ◽  
Water Distribution Network ◽  
Gradient Algorithm ◽  
Global Gradient Algorithm ◽  
Pressure Driven Analysis ◽  
Pressure Driven

scholarly journals Testing linear solvers for global gradient algorithm

2014 ◽  
Vol 16 (5) ◽  
pp. 1178-1193 ◽  
Author(s):  
Orazio Giustolisi ◽  
Naser Moosavian
Keyword(s):  
Linear System ◽  
Water Distribution ◽  
Direct Method ◽  
Mathematical Problem ◽  
Network Models ◽  
Water Distribution Network ◽  
Mass Conservation ◽  
Gradient Algorithm ◽  
Global Gradient Algorithm ◽  
Pressure Driven

Steady-state Water Distribution Network models compute pipe flows and nodal heads for assumed nodal demands, pipe hydraulic resistances, etc. The nonlinear mathematical problem is based on energy and mass conservation laws which is solved by using global linearization techniques, such as global gradient algorithm (GGA). The matrix of coefficients of the linear system inside GGA belongs to the class of sparse, symmetric and positive definite. Therefore a fast solver for the linear system is important in order to achieve the computational efficiency, especially when multiple runs are required. This work aims at testing three main strategies for the solution of linear systems inside GGA. The tests are performed on eight real networks by sampling nodal demands, considering the pressure-driven and demand-driven modelling to evaluate the robustness of solvers. The results show that there exists a robust specialized direct method which is superior to all the other alternatives. Furthermore, it is found that the number of times the linear system is solved inside the GGA does not depend on the specific solver, if a small regularization to the linear problem is applied, and that pressure-driven modelling requires a greater number which depends on the size and topology of the network and not only on the level of pressure deficiency.

scholarly journals The New Set Up of Local Performance Indices into WaterNetGen and Application to Santarém’s Network

2020 ◽  
Vol 2 (1) ◽  
pp. 18 ◽  
Author(s):  
Marco Amos Bonora ◽  
Fabio Caldarola ◽  
Mario Maiolo ◽  
Joao Muranho ◽  
Joaquim Sousa
Keyword(s):  
Water Distribution ◽  
Global Analysis ◽  
Distribution Network ◽  
Water Distribution Network ◽  
Mathematical Framework ◽  
Water Networks ◽  
Performance Indices ◽  
Set Up ◽  
Pressure Driven Analysis

A new set of local performance indices has recently been introduced within a mathematical framework specifically designed to promote a local–global analysis of water networks. Successively, some local indices were also set up and implemented on WaterNetGen to better exploit their potential. In this paper, after a very brief overview of tools and main notations, Santarém’s (Portugal) water distribution network (WDN) is examined, applying to it the mentioned set of local indices, as a new real case study. The paper also focuses on the Hypotesis required to assess these indices in a pressure driven analysis (PDA) approach, analyzing and discussing the results obtained from such a simulation.

scholarly journals Improved Hydraulic Simulation of Valve Layout Effects on Post-Earthquake Restoration of a Water Distribution Network

2020 ◽  
Vol 12 (8) ◽  
pp. 3492
Author(s):  
Jeongwook Choi ◽  
Doosun Kang
Keyword(s):  
Water Distribution ◽  
Distribution Network ◽  
Water Distribution Network ◽  
Seismic Damage ◽  
Hydraulic Analysis ◽  
Hydraulic Simulation ◽  
Restoration Process ◽  
Restoration Strategies ◽  
The Impact ◽  
Pressure Driven Analysis

To restore water pipes damaged by earthquakes, it is common to block the water flow by closing the associated shut-off valves. In this process, water supply suspension in the area connected to the isolated pipes is inevitable, which decreases the serviceability of the water distribution network (WDN). In this study, we identified the impact of valve layout (i.e., number and location) on system serviceability during a seismic damage restoration process. By conducting a pressure-driven-analysis (PDA) using EPANET 3.0, a more realistic hydraulic analysis could be carried out under the seismically damaged condition. Furthermore, by considering the valve-controlled segment in the hydraulic simulation, a more realistic water suspension area was determined, and efficient seismic damage restoration strategies were identified. The developed model was implemented on a WDN to demonstrate the effect of valve layout on the post-earthquake restoration process. Finally, effective restoration strategies were suggested for the application network.

Uncertainty quantification of pressure-driven analysis for water distribution network modeling

2015 ◽  
Vol 16 (3) ◽  
pp. 599-610 ◽  
Author(s):  
Ho Min Lee ◽  
Do Guen Yoo ◽  
Doosun Kang ◽  
Hwandon Jun ◽  
Joong Hoon Kim
Keyword(s):  
Negative Pressure ◽  
Water Distribution ◽  
Real Life ◽  
Water Distribution Network ◽  
Distribution Networks ◽  
Operating Conditions ◽  
Service Reliability ◽  
High Degree ◽  
Pressure Driven Analysis ◽  
Pressure Driven

The hydraulic analysis of water distribution networks (WDNs) is divided into two approaches: namely, a demand-driven analysis (DDA) and a pressure-driven analysis (PDA). In the DDA, the basic assumption is that the nodal demand is fully supplied irrespective of the nodal pressure, which is mainly suitable for normal operating conditions. However, in abnormal conditions, such as pipe failures or unexpected increase in demand, the DDA approach may cause unrealistic results, such as negative pressure. To address the shortcomings of DDA, PDA has been considered in a number of studies. For PDA, however, the head-outflow relation (HOR) should be given, which is known to contain a high degree of uncertainty. Here, the DDA-based simulator, EPANET2 was modified to develop a PDA model simulating pressure deficient conditions and a Monte Carlo simulation (MCS) was performed to consider the quantitative uncertainty in HOR. The developed PDA model was applied to two networks (a well-known benchmark system and a real-life WDN) and the results showed that the proposed model is superior to other reported models when dealing with negative pressure under abnormal conditions. In addition, the MCS-based sensitivity analysis presents the ranges of pressure and available discharge, quantifying service reliability of water networks.

scholarly journals Equivalent hydraulic resistance to simulate pipes subject to diffuse outflows

2011 ◽  
Vol 14 (1) ◽  
pp. 65-74 ◽  
Author(s):  
M. Ferrante ◽  
E. Todini ◽  
C. Massari ◽  
B. Brunone ◽  
S. Meniconi
Keyword(s):  
Hydraulic Resistance ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Distribution Network ◽  
Network Models ◽  
Water Distribution Network ◽  
Simulation Models ◽  
Gradient Algorithm ◽  
Present Generation

In water distribution network simulation models, pipes subject to diffuse outflow, either due to connections or to distributed demand or to leaks along their length, are generally converted into pipe elements only subject to lumped demand at their ending nodes. This approximation, which disregards the flow variation along the pipes, generates a loss of axial momentum, which is not correctly taken into account in the present generation of water distribution network models. In this paper a correction to the lumped demand approximation is provided and this equivalence is analyzed within the framework of the Global Gradient Algorithm. This is obtained through a correction of the pipe hydraulic resistance; this approach has proven to be more effective than the use of an asymmetrical lumped demand of the total distributed outflow at the pipe ending nodes. In order to assess the effect of the introduced correction, an application to a simple water distribution system is finally provided.

scholarly journals Resilience Analysis in the Permanent Partitioning of a Water Distribution Network

10.29007/lpck ◽  
2018 ◽  
Author(s):  
Enrico Creaco ◽  
Armando Di Nardo ◽  
Carlo Giudicianni ◽  
Roberto Greco ◽  
Giovanni Francesco Santonastaso
Keyword(s):  
Energy Efficiency ◽  
Performance Indicators ◽  
Water Distribution ◽  
Scientific Literature ◽  
Distribution Network ◽  
Water Distribution Network ◽  
Distribution Networks ◽  
Water Distribution Networks ◽  
The Creation ◽  
Pressure Driven

This paper aims to explore the suitability of compact resilience metrics for application to partitioned water distribution networks (WDNs). WDN partitioning represents a different test from the usual reliability tests performed in the scientific literature, in which the operation of the WDN is unperturbed, or marginally perturbed (e.g., by segment isolation or demand amplification). The creation of permanent district metering areas (DMAs), which is carried out through the simultaneous closure of numerous links, represents, instead, a larger and permanent perturbation that deserves special attention. In this analysis, two metrics, namely the Global Resilience Failure (GRF) and the energy efficiency indices, were compared in pressure-driven approach with WDN performance indicators. The results in a real WDN, which is partitioned in a growing number of DMAs, proved that both the GRF is more sensitive to the weaknesses arisen in the partitioning processes.

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