Estimation of Decay Coefficients for Unsteady Friction for Instantaneous, Acceleration-Based Models

Reddy, Haritha P.; Silva-Araya, Walter F.; Chaudhry, M. Hanif

doi:10.1061/(asce)hy.1943-7900.0000508

Cited by 27 publications

(6 citation statements)

References 40 publications

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“…These results also demonstrate that the first-order FVM is as good as the MOC, which was also demonstrated by Pal et al [53]. In addition, the FVM method [53] was also validated with experimental data, as demonstrated by USC-2 in the work of Reddy et al [88] In a further study, a validation exercise was undertaken for first-order and secondorder FVMs as per the methodology presented in Pal et al [53]. A frictionless pipe system with a large reservoir at the upstream and a valve at the downstream was considered.…”

Section: Figure 13supporting

confidence: 77%

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An Overview of the Numerical Approaches to Water Hammer Modelling: The Ongoing Quest for Practical and Accurate Numerical Approaches

Pal

Hanmaiahgari

Karney

2021

Water

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Here, recent developments in the key numerical approaches to water hammer modelling are summarized and critiqued. This paper summarizes one-dimensional modelling using the finite difference method (FDM), the method of characteristics (MOC), and especially the more recent finite volume method (FVM). The discussion is briefly extended to two-dimensional modelling, as well as to computational fluid dynamics (CFD) approaches. Finite volume methods are of particular note, since they approximate the governing partial differential equations (PDEs) in a volume integral form, thus intrinsically conserving mass and momentum fluxes. Accuracy in transient modelling is particularly important in certain (typically more nuanced) applications, including fault (leakage and blockage) detection. The FVM, first advanced using Godunov’s scheme, is preferred in cases where wave celerity evolves over time (e.g., due to the release of air) or due to spatial changes (e.g., due to changes in wall thickness). Both numerical and experimental studies demonstrate that the first-order Godunov’s scheme compares favourably with the MOC in terms of accuracy and computational speed; with further advances in the FVM schemes, it progressively achieves faster and more accurate codes. The current range of numerical methods is discussed and illustrated, including highlighting both their limitations and their advantages.

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Section: Figure 13supporting

confidence: 77%

Section: Figure 13supporting

confidence: 73%

An Overview of the Numerical Approaches to Water Hammer Modelling: The Ongoing Quest for Practical and Accurate Numerical Approaches

Pal

Hanmaiahgari

Karney

2021

Water

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“…The friction factor was considered to be steady with a value of 0.02, since this study was numerical verification-oriented. Readers can refer to related studies regarding unsteady friction [51,52]. Equations (8) and (9) are respectively the momentum and continuity equations.…”

Section: Hydraulic Transient Model and Faults In The Pipelinementioning

confidence: 99%

An Inverse Transient-Based Optimization Approach to Fault Examination in Water Distribution Networks

Lin

Yeh

2019

Water

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This research introduces an inverse transient-based optimization approach to automatically detect potential faults, such as leaks, partial blockages, and distributed deteriorations, within pipelines or a water distribution network (WDN). The optimization approach is named the Pipeline Examination Ordinal Symbiotic Organism Search (PEOS). A modified steady hydraulic model considering the effects of pipe aging within a system is used to determine the steady nodal heads and piping flow rates. After applying a transient excitation, the transient behaviors in the system are analyzed using the method of characteristics (MOC). A preliminary screening mechanism is adopted to sift the initial organisms (solutions) to perform better to reduce most of the unnecessary calculations caused by incorrect solutions within the PEOS framework. Further, a symbiotic organism search (SOS) imitates symbiotic relationship strategies to move organisms toward the current optimal organism and eliminate the worst ones. Two experiments on leak and blockage detection in a single pipeline that have been presented in the literature were used to verify the applicability of the proposed approach. Two hypothetical WDNs, including a small-scale and large-scale system, were considered to validate the efficiency, accuracy, and robustness of the proposed approach. The simulation results indicated that the proposed approach obtained more reliable and efficient optimal results than other algorithms did. We believe the proposed fault detection approach is a promising technique in detecting faults in field applications.

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“…On the other hand, the IAB model can be more suitable for practical applications for large-scale and complex pipe systems compared to the WFB model due to its high computational efficiency without the convolutional computation. It was found that the implementation of the IAB unsteady friction model in the 1D water-hammer model does not significantly increase computation time compared to those cases using only the steady friction term (Vitkovsky et al 2000;Reddy et al 2012). However, the IAB model-for which a thermodynamics framework is given in Axworthy et al (2000)-was developed empirically based on various experimental tests and applications (Brunone et al 1995;Brunone and Golia 2008;Bergant et al 2001).…”

Section: Introductionmentioning

confidence: 99%

“…Thus, the main disadvantage of applying this IAB model is the need for precalibration for the empirical coefficient, k d , based on the available data in a specific system, which potentially increases the work load and uncertainties in practical applications. Although many researchers have investigated the determination and improvement of the k d coefficient (Bergant and Simpson 1994;Bughazen and Anderson 1996;Pezzinga 2000;Vardy and Brown 1996;Reddy et al 2012), so far there is not yet a general coefficient expression for the IAB model that is valid and applicable for all practical cases. Moreover, many studies have implied that this k coefficient in the IAB model would be time and space dependent in transient pipe flow simulations (Vitkovsky et al 2000;Brunone et al 2004;Storli and Nielsen 2011a, b), which makes the calibration and application of this IAB model case sensitive.…”

Section: Introductionmentioning

confidence: 99%

Local and Integral Energy-Based Evaluation for the Unsteady Friction Relevance in Transient Pipe Flows

et al. 2017

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Unsteady friction and its modeling have been widely studied in transient pipe flows for its influences and modification effect on pressure waves. Such a feature is of great importance particularly in pipe systems where the extreme pressure values are due to the overlapping of pressure waves generated in different sections. This paper investigates the relevance of unsteady friction term by considering different models available in the literature. In particular, attention is focused on the following two commonly used one-dimensional (1D) models: the weighting function-based (WFB) model and the instantaneous acceleration-based (IAB) model. The investigation is executed using laboratory experiments and field tests as well as 1D/2D numerical simulations in simple pipeline systems. Realistic ranges of both initial (pretransient) conditions and geometrical characteristics are considered. The data collected in experimental tests are first used to calibrate the unsteady friction models under investigation. The validated models are then applied to identify their respective domains of applicability and the limitations. The differences between models and data are measured using the local transient analysis (LTA) norm and the integral total energy (ITE) norm along the pipeline, and the reasons for such discrepancies are explored in the paper. The practical implications of the use and improvements of different unsteady friction models for transient pipe flow simulations are discussed in the paper. individual papers. This paper is part of the Journal of Hydraulic Engineering, © ASCE, ISSN 0733-9429. © ASCE 04017015-1 J. Hydraul. Eng. J. Hydraul. Eng., 2017, 143(7): 04017015 Downloaded from ascelibrary.org by Hong Kong University of Sci and Tech (HKUST) on 06/05/19. Copyright ASCE. For personal use only; all rights reserved. © ASCE 04017015-2 J. Hydraul. Eng. J. Hydraul. Eng., 2017, 143(7): 04017015 Downloaded from ascelibrary.org by Hong Kong University of Sci and Tech (HKUST) on 06/05/19. Copyright ASCE. For personal use only; all rights reserved. © ASCE 04017015-5 J. Hydraul. Eng. J. Hydraul. Eng., 2017, 143(7): 04017015 Downloaded from ascelibrary.org by Hong Kong University of Sci and Tech (HKUST) on 06/05/19. Copyright ASCE. For personal use only; all rights reserved. © ASCE 04017015-6 J. Hydraul. Eng. J. Hydraul. Eng., 2017, 143(7): 04017015 Downloaded from ascelibrary.org by Hong Kong University of Sci and Tech (HKUST) on 06/05/19. Copyright ASCE. For personal use only; all rights reserved. © ASCE 04017015-8 J. Hydraul. Eng. J. Hydraul. Eng., 2017, 143(7): 04017015 Downloaded from ascelibrary.org by Hong Kong University of Sci and Tech (HKUST) on 06/05/19. Copyright ASCE. For personal use only; all rights reserved. © ASCE 04017015-9 J. Hydraul. Eng. J. Hydraul. Eng., 2017, 143(7): 04017015 Downloaded from ascelibrary.org by Hong Kong University of Sci and Tech (HKUST) on 06/05/19. Copyright ASCE. For personal use only; all rights reserved. © ASCE 04017015-11 J. Hydraul. Eng.

show abstract

Estimation of Decay Coefficients for Unsteady Friction for Instantaneous, Acceleration-Based Models

Cited by 27 publications

References 40 publications

An Overview of the Numerical Approaches to Water Hammer Modelling: The Ongoing Quest for Practical and Accurate Numerical Approaches

An Overview of the Numerical Approaches to Water Hammer Modelling: The Ongoing Quest for Practical and Accurate Numerical Approaches

An Inverse Transient-Based Optimization Approach to Fault Examination in Water Distribution Networks

Local and Integral Energy-Based Evaluation for the Unsteady Friction Relevance in Transient Pipe Flows

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