The Reflection of Waterhammer Pressure Waves From Minor Losses

Contractor, D. N.

doi:10.1115/1.3650568

Cited by 46 publications

(17 citation statements)

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“…An impulse to research activity in the PS management derives from the unexpected reliability of transient test-based techniques with respect to more consolidated techniques in which pressure and flow measurements are carried out in steady-state conditions. With the exception of the work by Contractor (1965), in which attention was focused on the transient behavior of three closely spaced orifices producing a large local head loss, first steps were taken in the field of leak location and sizing. In 1994 Liggett and Chen proposed the use of the unsteady flow differential equations-the classic Inverse Transient Analysis (ITA)-as a tool for calibration, location and calculation of leaks in PS.…”

Section: Introductionmentioning

confidence: 99%

Small Amplitude Sharp Pressure Waves to Diagnose Pipe Systems

Meniconi

Brunone

Ferrante

et al. 2010

Water Resour Manage

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In this paper the possibility of using transient tests, generated by the Portable Pressure Wave Maker (PPWM) device, as a powerful tool in the management of pipe systems, is demonstrated. Specifically, tests carried out in different experimental set-ups at the Water Engineering Laboratory of the University of Perugia, Italy show that small amplitude sharp pressure waves produced by the PPWM allow to locate and evaluate the entity of anomalies, such as leaks, illegal branches, partial blockages, and negligently partially closed in-line valves. To improve the precision of localization of anomalies, arrival times of pressure waves are detected by means of wavelet analysis. Simple relations based on the water hammer theory are proposed to evaluate the entity of the anomalies.

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Section: Introductionmentioning

confidence: 99%

Small Amplitude Sharp Pressure Waves to Diagnose Pipe Systems

Meniconi

Brunone

Ferrante

et al. 2010

Water Resour Manage

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“…Moreover, the range of variability of the initial Reynolds number studied is very narrow and, because of their quite low values, concerns flow conditions that are quite unrealistic in real pipe systems. The interaction between a pressure wave and different partially closed in-line valves in a high density polyethylene (HDPE) pipe was examined by Meniconi et al (2011)-an extension of the pioneering paper by Contractor (1965)with particular attention to the mechanisms that give rise to the first pressure wave reflected by the in-line valve.…”

Section: Introductionmentioning

confidence: 99%

Transient hydrodynamics of in-line valves in viscoelastic pressurized pipes: long-period analysis

et al. 2012

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The literature contains few reports devoted to the analysis of the effects of a partially closed in-line valve on the characteristics of transients in viscoelastic pressurized pipes. In this paper a contribution to the analysis of the long-period behavior of pressure is offered from both the experimental and numerical modeling point of view. In the first part, laboratory tests and the related results-noticeably extensive with respect to the existing literature-are examined. More precisely, the dependance of the damping of the dimensionless pressure maximum values on the initial conditions and in-line valve local head loss coefficient is shown. In the second part, a 1-D numerical model is developed by determining its parameters within a physically based procedure. Model parameters are obtained by considering transients in a constant-diameter pipe (single pipe) and then exported to the case of pipes with a partially closed in-line valve (in-line valve pipe). Moreover, particular attention is devoted to the modalities of specifying boundary conditions. In particular, the quasi-steady-state approach is followed for determining the transient local head loss due to the partially closed in-line valve and the actual supply conditions and characteristics of the maneuver are taken into account. Finally, the effect of unsteady friction and viscoelasticity is examined in both single and in-line valve pipes.

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“…Stephens et al (2005), Brunone et al (2008) and Duan et al (2012) proposed that blockages in pipes are divided into two categories-discrete and extended blockages-according to its relative length to the total pipeline length. In the context of discrete blockages, Contractor (1965) shows that a discrete partial blockage causes a partial reflection of a waterhammer wave where the amplitude of the reflected wave provides information on the severity of the constriction and the arrival time of the reflected wave provides the location of the blockage. The findings in Contractor (1965) have been confirmed and used for blockage detection by Wang et al (2005) and Meniconi et al (2009Meniconi et al ( , 2011Meniconi et al ( and 2012.…”

Section: Introductionmentioning

confidence: 99%

“…In the context of discrete blockages, Contractor (1965) shows that a discrete partial blockage causes a partial reflection of a waterhammer wave where the amplitude of the reflected wave provides information on the severity of the constriction and the arrival time of the reflected wave provides the location of the blockage. The findings in Contractor (1965) have been confirmed and used for blockage detection by Wang et al (2005) and Meniconi et al (2009Meniconi et al ( , 2011Meniconi et al ( and 2012. Wang et al (2005) showed that a discrete blockage in a pipe system introduces a frequency dependent damping to the transient signal and developed a technique for locating and sizing discrete blockages based on this damping.…”

Section: Introductionmentioning

confidence: 99%

Transient wave-blockage interaction and extended blockage detection in elastic water pipelines

Duan

Lee

Ghidaoui

et al. 2014

Journal of Fluids and Structures

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Abstract:Extended partial blockages are common in pressurized water pipelines and can result in the wastage of energy, the reduction in system carrying capacity and the increased potential for contamination. This paper investigates the transient wave-blockage interaction and its application to extended blockage detection in pipelines, where blockage-induced changes to the system resonant frequencies are observed. The frequency shifting is first inspected and explained in this study through wave perturbation analysis, providing a theoretical confirmation for the result that unlike discrete blockages, extended blockages cause resonant frequency shifts in the system. Furthermore, an analytical expression is derived for the relationship between the blockage properties and the resonant frequency shifts and is used to detect the blockages in this study. The obtained results are validated through both numerical applications and laboratory experiments, where the accuracy and efficiency of the developed method for extended blockage detection are tested.

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The Reflection of Waterhammer Pressure Waves From Minor Losses

Cited by 46 publications

References 0 publications

Small Amplitude Sharp Pressure Waves to Diagnose Pipe Systems

Small Amplitude Sharp Pressure Waves to Diagnose Pipe Systems

Transient hydrodynamics of in-line valves in viscoelastic pressurized pipes: long-period analysis

Transient wave-blockage interaction and extended blockage detection in elastic water pipelines

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