Parameter Identification in Pipeline Networks: Transient-Based Expectation-Maximization Approach for Systems Containing Unknown Boundary Conditions

Zecchin, Aaron C.; Lambert, Martin F.; Simpson, Angus R.; White, L.B.

doi:10.1061/(asce)hy.1943-7900.0000849

Cited by 17 publications

(6 citation statements)

References 16 publications

(2 reference statements)

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“…Figure 1 shows the graph of a general tree network. To clearly describe the network components and properties, a tree network is represented by a connected graph T(V, E) (Che et al, 2022;Zecchin et al, 2014), which includes the node set (i.e., all vertexes) V = {(v 1 ), (v 2 ), …, (v N )} and the pipe set (i.e., all edges) E = {[e 1 ], [e 2 ], …, [e P ]}, where v n = ID number of the nth node in V and e p = ID number of the pth pipe in E. Node set V can be further classified according to the direct connectivity of a node with boundaries (e.g., reservoirs, valves, and dead ends) -that is internal node set V in , where different pipe ends meet, and external node set V ex , where a pipe connects to a boundary, such that V = V in ∪ V ex , where ∪ = union operator (Karney & McInnis, 1992). An external node links only one pipe, whereas an internal node connects at least two pipes.…”

Section: Nomenclature Of Tree Networkmentioning

confidence: 99%

Modified Factorized Transient Wave Model in Tree Pipe Networks for Leak Localization With Less Boundary Measurements

Chuan

Wang

Zhou

et al. 2022

Water Resources Research

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In the United States (US), the total length of water mains is around 2 million kilometers (i.e., 50 times the equatorial circumference), most of which have been buried underground over half a century (Che et al., 2021). Due to aging without timely and effective renewal, a large portion of these pipes have reached or are reaching the end of their service lives. The quality of service to water users has been significantly going down in recent decades because of the occurring leaks in urban water supply systems (Alawadhi et al., 2018). It was estimated that the annual loss of drinking water worldwide is 126 billion m 3 (i.e., about 70 L per person per day), at a direct cost of US$39 billion, mostly from hidden leaks (Liemberger & Wyatt, 2019). Moreover, external contaminants can be easily drawn into the pipe system via leaks under low internal pressure conditions, which poses a serious threat to public health (

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Section: Nomenclature Of Tree Networkmentioning

confidence: 99%

Modified Factorized Transient Wave Model in Tree Pipe Networks for Leak Localization With Less Boundary Measurements

Chuan

Wang

Zhou

et al. 2022

Water Resources Research

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“…The network admittance matrix method (NAMM) proposed by Zecchin, Simpson, Lambert, White, and Vitkovsky (2009) is a frequency-domain model that organizes the transient governing equations for each link of a network in a laplacian matrix form. Its elegant structure makes this model appealing for the analysis of the response of complex systems to transients and for their diagnosis (Zecchin, Lambert, Simpson, and White, 2014).…”

Section: Introductionmentioning

confidence: 99%

Leak Detection in a Branched System by Inverse Transient Analysis with the Admittance Matrix Method

Capponi

Ferrante

Zecchin

et al. 2017

Water Resour Manage

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The diagnosis of water distribution systems by means of the inverse transient analysis requires efficient and reliable numerical models. In the network admittance matrix method (NAMM) the 1-D waterhammer governing equations are integrated in the frequency domain and organized in a laplacian matrix form. The NAMM is particularly suitable for complex systems because of this structure and can be used for the system diagnosis, including leak sizing and location. In this paper a damaged branched system is considered and the diagnosis is performed by means of the NAMM using experimental data from laboratory transient tests. Two different boundary conditions are used in the implementation of the NAMM and the leak is located and sized with a reasonable approximation. An extended numerical investigation is also presented and allows confirmation of the results for different leak locations. The use of the NAMM for the leak detection and the validation using experimental data on a branched system are the main original contributions of this work. The successful diagnosis indicates promising results for applications in more complex systems.

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“…In recent years, the use of fluid transients has been extended to non-invasively assess the condition of the pipe wall. Zecchin et al 33,34 studied general pipeline parameter identification using fluid transient waves but only limited to numerical analysis. Stephens et al 35,36 were the first to apply the inverse transient analysis (ITA) to detect degradation of the pipe wall in a mild steel cement mortar–lined (MSCL) pipeline.…”

Section: Introductionmentioning

confidence: 99%

On-site non-invasive condition assessment for cement mortar–lined metallic pipelines by time-domain fluid transient analysis

Gong

Stephens

Arbon

et al. 2015

Structural Health Monitoring

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Pipeline condition assessment is essential for targeted and cost-effective maintenance of aging water transmission and distribution systems. This article proposes a technique for fast and non-invasive assessment of the wall condition of cement mortar–lined metallic pipelines using fluid transient pressure waves (water hammer waves). A step transient pressure wave can be generated by shutting off a side-discharge valve in a pressurised pipeline. The wave propagates along the pipe and reflections occur when it encounters sections of pipe with changes in wall thickness. The wave reflections can be measured by pressure transducers as they are indicative of the location and severity of the wall deterioration. A numerical analysis is conducted to obtain the relationship between the degree of change in wall thickness in a cement mortar–lined pipe and the size of the corresponding pressure wave reflection. As a result, look-up charts are generated for any specific cement mortar–lined pipeline to map this relationship. The wall thickness of a deteriorated or distinct section can be determined directly and quickly from the charts using the size of the reflected wave, thus facilitating on-site pipeline condition assessment. The validity of this time-domain pipeline condition assessment technique is verified by numerical simulations and a case study using the field data measured in a mild steel cement mortar–lined water main in South Australia. The condition of the pipe as assessed by the proposed technique is generally consistent with ultrasonic measurements.

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Parameter Identification in Pipeline Networks: Transient-Based Expectation-Maximization Approach for Systems Containing Unknown Boundary Conditions

Abstract: The simulation of hydraulic transients within fluid line networks is important for many ap-

Cited by 17 publications

References 16 publications

Modified Factorized Transient Wave Model in Tree Pipe Networks for Leak Localization With Less Boundary Measurements

Modified Factorized Transient Wave Model in Tree Pipe Networks for Leak Localization With Less Boundary Measurements

Leak Detection in a Branched System by Inverse Transient Analysis with the Admittance Matrix Method

On-site non-invasive condition assessment for cement mortar–lined metallic pipelines by time-domain fluid transient analysis

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