Subatmospheric pressure in a water draining pipeline with an air pocket

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

doi:10.1080/1573062x.2018.1475578

Cited by 25 publications

(34 citation statements)

References 24 publications

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“…To verify the proposed model, comparisons between computed and measured air pocket pressure oscillations were conducted using a constant friction factor of 0.018, considering the previous work published by the authors [16]. The water column located from X = 0 m to X = 3.4 m (see Figure 3) represents a boundary condition of the system since according to the observations it remains static during all measurements; then, it was neglected for the analysis in the mathematical model.…”

Section: Model Verificationmentioning

confidence: 99%

“…Furthermore, recent works have been developed to understand the behavior of an air pocket and setting operational rules in the emptying process to prevent future accidents. Several works have been published recently on the numerical simulation of the emptying process using one-dimensional (1D) models in case of having air inside a pipe [16,17]. Other works using advanced CFD techniques have been undertaken on the dynamic behavior of an air pocket over drainage and the effect of backflow air entrance [15,18].…”

Section: Introductionmentioning

confidence: 99%

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Effect of a Commercial Air Valve on the Rapid Filling of a Single Pipeline: a Numerical and Experimental Analysis

Coronado-Hernández

Besharat

Fuertes-Miquel

et al. 2019

Water

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The filling process in water pipelines produces pressure surges caused by the compression of air pockets. In this sense, air valves should be appropriately designed to expel sufficient air to avoid pipeline failure. Recent studies concerning filling maneuvers have been addressed without considering the behavior of air valves. This work shows a mathematical model developed by the authors which is capable of simulating the main hydraulic and thermodynamic variables during filling operations under the effect of the air valve in a single pipeline, which is based on the mass oscillation equation, the air-water interface, the polytropic equation of the air phase, the air mass equation, and the air valve characterization. The mathematical model is validated in a 7.3-m-long pipeline with a 63-mm nominal diameter. A commercial air valve is positioned in the highest point of the hydraulic installation. Measurements indicate that the mathematical model can be used to simulate this phenomenon by providing good accuracy.

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Section: Model Verificationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Effect of a Commercial Air Valve on the Rapid Filling of a Single Pipeline: a Numerical and Experimental Analysis

Coronado-Hernández

Besharat

Fuertes-Miquel

et al. 2019

Water

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“…Herein, a simplified mathematical model is presented for computing extreme values of main hydraulic and thermodynamic variables in draining and filling operations in water installations when neither an admitted nor expelled air flow exists for draining and filling operations, respectively [22,23]. The authors neglected the inertial term (dv/dt = 0) of the water phase [24,25]; consequently, the quasi-static flow model was obtained. Therefore, the simulation of these operations in water installations was based on three formulations: the quasi-static flow model to represent the water phase [1], the polytropic equation of an entrapped air pocket [26,27], and the piston flow model to simulate air-water interactions [28][29][30].…”

Section: Introductionmentioning

confidence: 99%

Quasi-static Flow Model for Predicting the Extreme Values of Air Pocket Pressure in Draining and Filling Operations in Single Water Installations

Coronado-Hernández

Fuertes-Miquel

Mora-Meliá

et al. 2020

Water

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Inertial models have been used by researchers to simulate the draining and filling processes in water pipelines, based on the evolution of the main hydraulic and thermodynamic variables. These models use complex differential equations, which are solved using advanced numerical codes. In this study, a quasi-static flow model is developed to study these operations in hydraulic installations. The quasi-static flow model represents a simplified formulation compared with inertial flow models, in which its numerical resolution is easier because only algebraic equations must be addressed. Experimental measurements of air pocket pressure patterns were conducted in a 4.36 m long single pipeline with an internal diameter of 42 mm. Comparisons between measured and computed air pocket pressure oscillations indicate how the quasi-static flow model can predict extreme values of air pocket pressure for experimental runs, demonstrating the possibility of selecting stiffness and pipe classes in actual pipelines using this model. Two case studies were analysed to determine the behaviour of the quasi-static flow model in large water pipelines.

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“…En estudios anteriores, el modelo matemático desarrollado por los autores se ha validado mediante ensayos de laboratorio con y sin ventosas y también con varias bolsas de aire en perfiles irregulares (Coronado-Hernández, 2017). Las dimensiones de estas instalaciones son pequeñas, con diámetros nominales inferiores a 63 mm y longitudes menores a 7.3 m (Coronado-Hernández, 2017Fuertes-Miquel, 2018a). En este trabajo se pretende validar el modelo para situaciones donde no se había analizado con anterioridad, para instalaciones reales de gran tamaño.…”

Section: Introductionunclassified

Maniobras de llenado y vaciado en grandes conducciones. Aplicación a una tubería de fundición DN400 en Massamagrell (Valencia, España)

et al. 2020

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<p>Debido a las bolsas de aire que hay en el interior de las tuberías durante los procesos de llenado y vaciado, se producen depresiones o sobrepresiones en el interior de las mismas, capaces de producir serios daños en las instalaciones. Para analizar todas las variables hidráulicas en las maniobras de llenado y vaciado, se opta por la aplicación de un modelo matemático, el cual es capaz de simular con exactitud el comportamiento de ambos fluidos, tanto la columna de agua como la bolsa de aire. El modelo propuesto por los autores ya ha sido validado en pequeñas instalaciones de laboratorio. En este trabajo, se pretende validar el modelo matemático en una instalación real de grandes dimensiones. Concretamente, se trata de una conducción de diámetro DN400, ubicada en Massamagrell (Valencia), donde se analizan las maniobras de llenado y de vaciado. Finalmente, se comparan los resultados que proporciona el modelo con las mediciones realizadas por la Empresa Mixta Metropolitana S.A. (EMIMET), obteniéndose una similitud muy aceptable.</p>

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Subatmospheric pressure in a water draining pipeline with an air pocket

Cited by 25 publications

References 24 publications

Effect of a Commercial Air Valve on the Rapid Filling of a Single Pipeline: a Numerical and Experimental Analysis

Effect of a Commercial Air Valve on the Rapid Filling of a Single Pipeline: a Numerical and Experimental Analysis

Quasi-static Flow Model for Predicting the Extreme Values of Air Pocket Pressure in Draining and Filling Operations in Single Water Installations

Maniobras de llenado y vaciado en grandes conducciones. Aplicación a una tubería de fundición DN400 en Massamagrell (Valencia, España)

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