Experimental and Numerical Analysis of a Water Emptying Pipeline Using Different Air Valves

Coronado-Hernández, Óscar E.; Fuertes-Miquel, Vicente S.; Besharat, Mohsen; Ramos, Helena M.

doi:10.3390/w9020098

Cited by 43 publications

(82 citation statements)

References 24 publications

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“…In water supply networks, emptying maneuvers are required [5]. Knowing the behavior of transient flow, both water and air phase are important in order to simulate the emptying process; this is because the water flow will be replaced by the air flow.…”

Section: Introductionmentioning

confidence: 99%

“…This research presents the mathematical model developed by the authors [5,15] to analyze the emptying process, which was applied to the Ciudad del Bicentenario pipeline located in Cartagena, Bolívar Department, Colombia, in order to show the behavior of hydraulic and thermodynamic variables. The mathematical model can be used for engineers to conduct a water emptying process in pipelines in the design and planning stages to avoid the collapse of pipe systems.…”

Section: Introductionmentioning

confidence: 99%

“…The emptying process starts when drain valves are opened, and trapped air pockets are immediately expanded and values of sub-atmospheric pressure are reached. Water velocities should be varied from 0.3 to 0.6 m/s to do an appropriate operation [7], and air valves for vacuum protection should be installed adequately along of pipelines [5,15]. Air valves should open to admit an adequate quantity of air flow into the installation with a similar ratio than water flow in order to prevent sub-atmospheric pressure conditions.…”

Section: Introductionmentioning

confidence: 99%

“…The authors have developed a mathematical model to analyze the emptying process using experimental facilities [5,15], which was validated for a single pipe at the Universitat Politècnica de València, Spain [15] and for a pipeline of irregular profile at the University of Lisbon, Portugal [5]. The main hydraulic and thermodynamic variables (absolute pressure, water velocity, and length of the emptying columns) were measured during the experiments.…”

Section: Introductionmentioning

confidence: 99%

“…If trapped air is compressed, pressure surges occur [3,4]; in contrast, when it is expanded, then negative pressures are reached [5]. To avoid these situations, air valves should be installed along pipe systems since these devices relieve transient events through expelled/admitted air [6,7].…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Emptying Operation of Water Supply Networks

Coronado-Hernández

Fuertes-Miquel

Angulo-Hernandez³

2017

Water

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Abstract:Recently, emptying processes have been studied in experimental facilities in pipelines, but there is a lack regarding applications in actual pipelines, which permits establishing the risk of collapse because of sub-atmospheric pressure occurrence. This research presents a mathematical model to simulate the emptying process of water supply networks, and the application to a water emptying pipeline with nominal diameter of 1000 mm and 578 m long which is located on the southern of Cartagena, Bolívar Deparment, Colombia. In the application, both pipes and the air valve data manufacturer were considered. The behavior of all hydraulic and thermodynamic variables is considered. Results show that is crucial to know sub-atmospheric pressure values to prevent the collapse of the pipeline. The application of the mathematical model confirms that the hydraulic system is well designed depending on air valve sizes and maneuvering of drain valve.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Emptying Operation of Water Supply Networks

Coronado-Hernández

Fuertes-Miquel

Angulo-Hernandez³

2017

Water

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Closure to “Rigid Water Column Model for Simulating the Emptying Process in a Pipeline Using Pressurized Air” by Oscar E. Coronado-Hernández, Vicente S. Fuertes-Miquel, Pedro L. Iglesias-Rey, and Francisco J. Martínez-Solano

et al. 2020

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This closure addresses how the mathematical model developed by the authors is appropriate to simulate emptying processes using pressurized air in pipelines of undulating profiles since it is based on physical equations. The writers thank the discussers for providing information regarding experimental data in the published paper of Laanearu et al. (2012) and for the comments in their discussion.The mathematical model developed by the authors considers three assumptions. These assumptions are (1) a rigid water column model (RWCM) can be used to represent the water behavior, (2) the air-water interface is perpendicular to the pipe direction, and (3) there is a constant friction factor. The discussers agree with Assumptions 1 and 3; however, they disagree with Assumption 2 about the definition of the shape of the air-water interface.The authors assume a piston-flow model to represent the air-water interface considering that the air tank is capable of pressurizing the pipe installation with initial gauge pressures ranging from 10 to 20 m H20 . Laanearu et al. (2012) reported initial values of the air-water front (x i ). The initial length of the water column (L e0 ) was calculated by the authors from the air-water position (with a reference point at x ¼ 0 m) to the location of the discharge valve (x ¼ 271.6 m) [ Fig. 2 and Table 3 of Laanearu et al. (2012)]. In this sense, the initial length of the water column corresponds to the region of pressurized flow of the pipe installation. The part of water corresponding to the free-surface flow was neglected during simulations. The total length of the pipeline (L T ) is 314.1 m (Tijsseling et al. 2016). Initial water columns vary from 91% to 93% regarding the total length of the pipeline installation for all runs. These percentages show that the piston-flow model can be used to represent the behavior of the air-water interface. The remaining percentage of the total length is occupied as either a free-surface flow or pressurized air.The mathematical model presented in the original paper is based on physical equations; therefore, undulating profiles of pipelines can be modeled (Coronado-Hernández et al. 2017;Fuertes-Miquel et al. 2019). The discussers mentioned that the authors did not consider the pipe bridge and the upstream vertical leg to simulate the emptying process. Then, the gravity term (Δz=L e ) was modified in order to consider these pipe branches (Coronado-Hernández et al. 2018a, b). Fig. 1 shows six possible positions of the air-water interface. Positions 5 and 6 were considered in the original paper. Table 1 presents the corresponding values of the gravity term.Results of the mathematical model neglecting the pipe bridge were compared to the scenario considering it. Fig. 2 shows the comparison of the water flow oscillation pattern and gauge pressure pattern for Run 4. The pipe bridge does not affect the behavior of the water movement. A small discrepancy of the gauge pressure pattern was found between 4 and 6 s, which was generated by the pipe bridge. Results co...

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Experimental Investigation of the Effects of Air Pocket Configuration on Fluid Transients in a Pipeline

Alexander

Lee

et al. 2020

J. Hydraul. Eng.

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Air pockets entrapped in pipeline systems are required to be non-intrusively diagnosed by fluid transients. In this study, experimental investigations are used to compare the transient transmission and reflection effects of stationary in-line and off-line air pocket volumes along a pipe under zero base flow conditions. Comparison with theoretical modelling indicated that the difference in the transient response between the two configurations is primarily due to the inertia in the connecting water column associated with off-line air pockets. This means that the transient response depends on both the volume of the pocket and the dimensions of the cavity. Analysis in the frequency domain showed that the off-line air pocket may be characterised by the resonant frequency, at

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Experimental and Numerical Analysis of a Water Emptying Pipeline Using Different Air Valves

Cited by 43 publications

References 24 publications

Emptying Operation of Water Supply Networks

Emptying Operation of Water Supply Networks

Closure to “Rigid Water Column Model for Simulating the Emptying Process in a Pipeline Using Pressurized Air” by Oscar E. Coronado-Hernández, Vicente S. Fuertes-Miquel, Pedro L. Iglesias-Rey, and Francisco J. Martínez-Solano

Experimental Investigation of the Effects of Air Pocket Configuration on Fluid Transients in a Pipeline

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