scholarly journals Experimental investigation of leak hydraulics

2012 ◽  
Vol 15 (3) ◽  
pp. 666-675 ◽  
Author(s):  
M. Ferrante ◽  
C. Massari ◽  
E. Todini ◽  
B. Brunone ◽  
S. Meniconi
Keyword(s):  
Distribution Systems ◽  
Water Distribution ◽  
Network Models ◽  
Water Distribution Network ◽  
Experimental Tests ◽  
Pressure Control ◽  
Pipe Material ◽  
Governing Equations ◽  
The One ◽  
Definition Of

In recent decades the hydraulics of leaks, i.e. the definition of the relationships linking the hydraulic quantities in pipes with leaks, has received increasing attention. On the one hand, the definition of the relationship between the leak outflow and the relevant parameters – e.g. the leak area and shape, the pressure inside the pipe and outside the leak, and the pipe material – is crucial for pressure control and inverse analysis techniques. On the other hand, if the effect of the leakage on the governing equations is not taken into account, i.e. the loss of the flow axial momentum is not considered, significant errors can be introduced in the simulation of water distribution systems. In this paper, the governing equations for a pipe with a leak are derived. The basic equations, obtained within different approaches, are presented in a consistent formulation and then compared with the results of some experimental tests. The leak jet angle and other major features of the results are analysed. The estimated values of the parameters can be used in the water distribution network models when pipes with a diffuse leakage are considered.

scholarly journals Online simplification of water distribution network models for optimal scheduling

2013 ◽  
Vol 15 (3) ◽  
pp. 652-665 ◽  
Author(s):  
Daniel Paluszczyszyn ◽  
Piotr Skworcow ◽  
Bogumil Ulanicki
Keyword(s):  
Distribution Systems ◽  
Water Distribution ◽  
Distribution Network ◽  
Network Models ◽  
Water Distribution Network ◽  
Simplified Model ◽  
Reduced Model ◽  
Water Network ◽  
Pump Speed ◽  
Online Optimisation

This paper presents an implementation of an extended simplification algorithm of water distribution network models for the purpose of inclusion in the online optimisation strategy for energy and leakage management in water distribution systems. Whereas the previously proposed reduced model represented accurately the original hydraulic water network characteristics, the energy distribution in the simplified model was not preserved. This could cause a situation where the pump speed required to satisfy specified minimum pressure constraints is different for the reduced model and the original model. This problem has been identified, and an appropriate modification to the simplification algorithm has been introduced. The idea comprises introduction of the energy audit of the water network and the calculation of new minimum service pressure constraints for the simplified model. The approach allows the preservation of both hydraulic and energetic characteristics of the original water network and therefore meets the requirements of the online optimisation strategy. Suitability of the proposed approach is evaluated via a case study. The modern parallel programming implementation allowed water network models consisting of several thousand elements to be reduced within 2 min with an average relative accuracy of less than 2% in terms of tanks flows.

Leak behaviour in pressurized PVC pipes

2013 ◽  
Vol 13 (4) ◽  
pp. 987-992 ◽  
Author(s):  
M. Ferrante ◽  
C. Massari ◽  
B. Brunone ◽  
S. Meniconi
Keyword(s):  
Distribution Systems ◽  
Water Distribution ◽  
Numerical Models ◽  
Pipe Material ◽  
Correct Definition ◽  
Total Head ◽  
Definition Of ◽  
The University ◽  
The Relationship ◽  
Strain Measures

The correct definition of the leak law, i.e. the relationship between the leak outflow, the total head at the leak and other relevant parameters such as the pipe material, can seriously affect the accuracy of the numerical models used for the management of water distribution systems, either if they are used to forecast the leakage reduction by pressure management or to locate and size the leaks within an inverse analysis. In recent decades the use of the classical Torricelli or orifice equation has been questioned in the sense that some experimental results clearly demonstrated that the assumption of a leak outflow proportional to the square root of the head drop can yield unsatisfactory results. To investigate this behaviour, an experimental activity has been carried out at the Water Engineering Laboratory of the University of Perugia, Italy. Part of the results of the carried out tests are presented in this paper for a leak in a polyvinyl chloride (PVC) pipe. Leak laws based on the assumption of a leak area variation with the pressure are compared and validated by strain measures close to the leak.

scholarly journals Study of the variation of haloacetic acids in a simulated water distribution network

2018 ◽  
Vol 19 (1) ◽  
pp. 88-96
Author(s):  
Rojacques Mompremier ◽  
Óscar Arturo Fuentes Mariles ◽  
José Elías Becerril Bravo ◽  
Kebreab Ghebremichael
Keyword(s):  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution Network ◽  
Organic Content ◽  
Chlorine Concentration ◽  
Haloacetic Acids ◽  
Feed Water ◽  
Pipe Material ◽  
Pipe Materials

Abstract This paper presents the analysis of the variation of haloacetic acids (HAAs) for different pipe materials in a distribution system. The work involved an experimental study on a simulated distribution system assembled in the Hydraulic Laboratory of the Engineering Institute at the National Autonomous University of Mexico (Instituto de Ingeniería UNAM). Two different scenarios were investigated based on different pipe materials, variation of temperature and initial chlorine concentrations (4.0 and 4.5 mg/L). Feed water with varying amounts of organic content was dosed with varying amounts of chlorine concentration. Water samples were collected from different locations in the distribution system and analyzed for physicochemical properties and HAAs determination. The results of this research demonstrated that the concentration of HAAs in the different segments of the distribution systems varied depending on pipe material, initial chlorine concentration, pH, residence time and the presence of natural organic matter.

scholarly journals Optimal placement of valves in a water distribution network with CLP(FD)

2011 ◽  
Vol 11 (4-5) ◽  
pp. 731-747 ◽  
Author(s):  
MASSIMILIANO CATTAFI ◽  
MARCO GAVANELLI ◽  
MADDALENA NONATO ◽  
STEFANO ALVISI ◽  
MARCO FRANCHINI
Keyword(s):  
Logic Programming ◽  
Distribution Systems ◽  
Water Distribution ◽  
Distribution Network ◽  
Real Life ◽  
Water Distribution Network ◽  
Distribution Networks ◽  
Constraint Logic Programming ◽  
Optimal Placement ◽  
Isolation System

AbstractThis paper presents a new application of logic programming to a real-life problem in hydraulic engineering. The work is developed as a collaboration of computer scientists and hydraulic engineers, and applies Constraint Logic Programming to solve a hard combinatorial problem. This application deals with one aspect of the design of a water distribution network, i.e., the valve isolation system design. We take the formulation of the problem by Giustolisi and Savić (2008 Optimal design of isolation valve system for water distribution networks. InProceedings of the 10th Annual Water Distribution Systems Analysis Conference WDSA2008, J. Van Zyl, A. Ilemobade, and H. Jacobs, Eds.) and show how, thanks to constraint propagation, we can get better solutions than the best solution known in the literature for the Apulian distribution network. We believe that the area of the so-calledhydroinformaticscan benefit from the techniques developed in Constraint Logic Programming and possibly from other areas of logic programming, such as Answer Set Programming.

scholarly journals Estimation of hazen williams’s constant for a residential water distribution network; GMDH and PSO approach

2018 ◽  
Vol 7 (2.1) ◽  
pp. 92
Author(s):  
Dharmendra Kumar Tyagi ◽  
Mrinmoy Majumder ◽  
Chander Kant ◽  
Ashish Prabhat Singh
Keyword(s):  
Fluid Flow ◽  
Pipe Flow ◽  
Water Distribution ◽  
Water Distribution Network ◽  
Pipe Material ◽  
Pipe Network ◽  
Closed Channel ◽  
Computation Techniques ◽  
Flow Potential ◽  
Residential Water

Hazen-William equation is used to estimate the Fluid flow in closed channel. There are various models for estimation of pipe flow, however the accuracy and reliability of models varies due to the empirical nature of the Hazen-William constant .the applicability of model also become constrained due to the dependency of constant on pipe material, dimension and flow potential. Different type of pipeline arranged in different Networks will require different value of the constant and is generally retrieved from the data collected for the pipe network. The case dependency of the model has makes the model erroneous and often subjective that is why the present study tries to propose a model which can be used for any network where the output will depend upon the inputs. In this aspect the soft computation techniques: - GMDH and PSO was utilized in an unconventional way to establish the value of CHW =f (H, L, V, D).  According to result the GMDH becomes the better model than the PSO where the accuracy is about 76.315%. 

scholarly journals Management of water distribution systems in PDA conditions using isolation valves: case studies of real networks

2019 ◽  
Vol 22 (4) ◽  
pp. 681-690 ◽  
Author(s):  
A. Fiorini Morosini ◽  
O. Caruso ◽  
P. Veltri
Keyword(s):  
Case Studies ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution System ◽  
Water Distribution Network ◽  
Optimal Number ◽  
System Management ◽  
System Control

Abstract The current paper reports on a case study investigating water distribution system management in emergency conditions when it is necessary to seal off a zone with isolation valves to allow repair. In these conditions, the pressure-driven analysis (PDA) is considered to be the most efficient approach for the analysis of a water distribution network (WDN), as it takes into account whether the head in a node is adequate to ensure service. The topics of this paper are innovative because, until now, previous approaches were based on the analysis of the network behaviour in normal conditions. In emergency conditions, it is possible to measure the reliable functioning of the system by defining an objective function (OF) that helps to choose the optimal number of additional valves in order to obtain adequate system control. The OF takes into account the new network topology by excluding the zone where the broken pipe is located. The results show that the solution did not improve significantly when the number of valves reached a threshold. The procedure applied to other real case studies seems to confirm the efficiency of the methodology even if further examination of other cases in different conditions is necessary.

scholarly journals Simultaneous Sensor Placement and Pressure Reducing Valve Localization for Pressure Control of Water Distribution Systems

Water ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1352 ◽  
Author(s):  
Cao ◽  
Hopfgarten ◽  
Ostfeld ◽  
Salomons ◽  
Li
Keyword(s):  
Control System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution Systems ◽  
Pressure Control ◽  
Operating Pressure ◽  
Pressure Reduction ◽  
Suggested Approach ◽  
Operation Conditions ◽  
Pressure Reducing Valve

Many studies on pressure sensor (PS) placement and pressure reducing valve (PRV) localization in water distribution systems (WDSs) have been made with the objective of improving water leakage detection and pressure reduction, respectively. However, due to varying operation conditions, it is expected to realize pressure control using a number of PSs and PRVs to keep minimum operating pressure in real-time. This study aims to investigate the PS placement and PRV localization for the purpose of pressure control system design for WDSs. For such a control system, a PS should be positioned to represent the pressure patterns of a region of the WDS. Correspondingly, a PRV should be located to achieve a maximum pressure reduction between two neighboring regions. According to these considerations, an approach based on the k-means++ method for simultaneously determining the numbers and positions of both PSs and PRVs is proposed. Results from three case studies are presented to demonstrate the effectiveness of the suggested approach. It is shown that the sensors positioned have a high accuracy of pressure representation and the valves localized lead to a significant pressure reduction.

An integrated approach to water distribution network monitoring and performance prediction using geographical information systems

2003 ◽  
Vol 3 (1-2) ◽  
pp. 307-312 ◽  
Author(s):  
M. Poulton
Keyword(s):  
Decision Making ◽  
Geographical Information Systems ◽  
Distribution Systems ◽  
Water Distribution ◽  
Prediction Models ◽  
Process Integration ◽  
Water Distribution Network ◽  
Integrated Approach ◽  
Geographical Information ◽  
Measurement Technology

The deterioration of water distribution systems and the subsequent need for major rehabilitation has provided researchers with a challenge: to seek new techniques to facilitate decision-making and assist network planners. Consequently, a range of methods have been developed, concerning several key performance indicators. Those with the greatest potential tend to promote a pro-active approach to pipeline rehabilitation, by predicting future performance of individual or groups of pipes. Such an approach is essential if cost-effective solutions are to be found. Prediction models are based on indicators that are perceived to be the most appropriate for measuring and comparing an aspect of performance. The level of “appropriateness” is influenced not only by the availability of data and the ease at which it can be recorded, but also its accuracy and unambiguity. Consequently, indicators such as burst rates are widely used to assess structural performance. Ideally though, a more direct measure of the condition of a pipe could be used, such as its remaining wall thickness. This has previously been largely disregarded, due to the lack of appropriate (non-destructive) measurement technology. However, technological advances are being made to enable the inline monitoring of pipes and determination of deficiencies (particularly corrosion pits in cast iron pipes). This paper illustrates how online condition monitoring of distribution pipelines can be combined with existing prediction models, to facilitate the decision-making process. Integration is achieved through the use of a Geographical Information System (GIS), which greatly enhances representation of spatial and temporal information.

Robustness of Parameter-Less Remote Real-Time Pressure Control in Water Distribution Systems

2018 ◽  
pp. 449-463
Author(s):  
Philip R. Page ◽  
Adnan M. Abu-Mahfouz ◽  
Olivier Piller ◽  
Matome L. Mothetha ◽  
Muhammad S. Osman
Keyword(s):  
Real Time ◽  
Distribution Systems ◽  
Water Distribution ◽  
Time Pressure ◽  
Water Distribution Systems ◽  
Pressure Control

Numerical modeling of pressure-reducing valves in water distribution network systems

1990 ◽  
Vol 17 (4) ◽  
pp. 547-557
Author(s):  
U. S. Panu
Keyword(s):  
Numerical Modeling ◽  
Network Analysis ◽  
Friction Factor ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution Network ◽  
Water Model ◽  
Network Systems ◽  
Proposed Modification ◽  
Analysis Models

Computer models are no longer viewed as exotic luxuries, rather they are being increasingly accepted as necessities for effective planning and operation of water distribution systems. In large networks, pressure-reducing valves (PRVs) are common water appurtenances. However, through the use of the Hazen–Williams friction factor, there are difficulties in representing PRVs in network-analysis models. This paper focuses on these difficulties and suggests a procedure for resolving them through the use of modified Hazen–Williams friction factor. The effectiveness of the proposed modification in representing PRVs in the WATER model is demonstrated. Key words: network analysis, numerical modeling, hydraulics, municipal, water distribution, PRV representation, friction coefficient, Hazen–Williams, flow rate, simulations.

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