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The study of draining processes without admitting air has been conducted using only steady friction formulations in the implementation of governing equations. However, this hydraulic event involves transitions from laminar to turbulent flow, and vice versa, because of the changes in water velocity. In this sense, this research improves the current mathematical model considering unsteady friction models. An experimental facility composed by a 4.36 m long methacrylate pipe was configured, and measurements of air pocket pressure oscillations were recorded. The mathematical model was performed using steady and unsteady friction models. Comparisons between measured and computed air pocket pressure patterns indicated that unsteady friction models slightly improve the results compared to steady friction models.
Óscar Coronado-Hernández; Ivan Derpich; Vicente Fuertes-Miquel; Jairo Coronado-Hernández; Gustavo Gatica. Assessment of Steady and Unsteady Friction Models in the Draining Processes of Hydraulic Installations. Water 2021, 13, 1888 .
AMA StyleÓscar Coronado-Hernández, Ivan Derpich, Vicente Fuertes-Miquel, Jairo Coronado-Hernández, Gustavo Gatica. Assessment of Steady and Unsteady Friction Models in the Draining Processes of Hydraulic Installations. Water. 2021; 13 (14):1888.
Chicago/Turabian StyleÓscar Coronado-Hernández; Ivan Derpich; Vicente Fuertes-Miquel; Jairo Coronado-Hernández; Gustavo Gatica. 2021. "Assessment of Steady and Unsteady Friction Models in the Draining Processes of Hydraulic Installations." Water 13, no. 14: 1888.
The draining operation involves the presence of entrapped air pockets, which are expanded during the phenomenon occurrence generating drops of sub-atmospheric pressure pulses. Vacuum air valves should inject enough air to prevent sub-atmospheric pressure conditions. Recently, this phenomenon has been studied by the authors with an inertial model, obtaining a complex formulation based on a system composed by algebraic-differential equations. This research simplifies this complex formulation by neglecting the inertial term, thus the Bernoulli’s equation can be used. Results show how the inertial model and the simplified mathematical model provide similar results of the evolution of main hydraulic and thermodynamic variables. The simplified mathematical model is also verified using experimental tests of air pocket pressure, water velocity, and position of the water column.
Óscar E. Coronado-Hernández; Vicente S. Fuertes-Miquel; Edgar E. Quiñones-Bolaños; Gustavo Gatica; Jairo R. Coronado-Hernández. Simplified Mathematical Model for Computing Draining Operations in Pipelines of Undulating Profiles with Vacuum Air Valves. Water 2020, 12, 2544 .
AMA StyleÓscar E. Coronado-Hernández, Vicente S. Fuertes-Miquel, Edgar E. Quiñones-Bolaños, Gustavo Gatica, Jairo R. Coronado-Hernández. Simplified Mathematical Model for Computing Draining Operations in Pipelines of Undulating Profiles with Vacuum Air Valves. Water. 2020; 12 (9):2544.
Chicago/Turabian StyleÓscar E. Coronado-Hernández; Vicente S. Fuertes-Miquel; Edgar E. Quiñones-Bolaños; Gustavo Gatica; Jairo R. Coronado-Hernández. 2020. "Simplified Mathematical Model for Computing Draining Operations in Pipelines of Undulating Profiles with Vacuum Air Valves." Water 12, no. 9: 2544.
Air pockets generated during emptying operations in pressurized hydraulic systems cause significant pressure drops inside pipes. To avoid these sudden pressure changes, one of the most widely used methods involves the installation of air valves along the pipeline route. These elements allow air exchange between the exterior and the interior of the pipe, which alleviates the pressure drops produced and thus prevents possible breaks or failures in the structure of the installation. This study uses a mathematical model previously validated by the authors in smaller installations to simulate all hydraulic variables involved in emptying processes over time. The purpose of these simulations is the validation of the mathematical model in real large-scale installations, and to do this, the results obtained with the mathematical model are compared with actual measurements made by the partner company. The hydraulic system selected for the study is a pipeline with a nominal diameter of 400 mm and a total length of 1020 m. The results obtained from the mathematical model show great similarity with the experimental measurements, thus validating the model for emptying large pipes.
Guillermo Romero; Vicente S. Fuertes-Miquel; Óscar E. Coronado-Hernández; Román Ponz-Carcelén; Francisco Biel-Sanchis. Transient Phenomena Generated in Emptying Operations in Large-Scale Hydraulic Pipelines. Water 2020, 12, 2313 .
AMA StyleGuillermo Romero, Vicente S. Fuertes-Miquel, Óscar E. Coronado-Hernández, Román Ponz-Carcelén, Francisco Biel-Sanchis. Transient Phenomena Generated in Emptying Operations in Large-Scale Hydraulic Pipelines. Water. 2020; 12 (8):2313.
Chicago/Turabian StyleGuillermo Romero; Vicente S. Fuertes-Miquel; Óscar E. Coronado-Hernández; Román Ponz-Carcelén; Francisco Biel-Sanchis. 2020. "Transient Phenomena Generated in Emptying Operations in Large-Scale Hydraulic Pipelines." Water 12, no. 8: 2313.
During the filling process in pressurized hydraulic systems, sudden pressure changes generated inside the pipes can cause significant damage. To avoid these excessive overpressures, air valves should be installed to allow air exchange between the inside and outside during the filling process. This study presents a mathematical model to analyse the hydraulic transients during filling processes. This model, which has already been validated in small laboratories, is now applied to real large-scale systems that consist of DN400 and DN600 pipelines from Empresa Mixta Metropolitana S.A (EMIMET – Group Global Omnium), which is the company that manages the water supply of the metropolitan area of Valencia (from the Drinking Water Treatment Station to the municipalities). The mathematical model for large pipes is validated by comparing the experimental measurements and the results of model.
Guillermo Romero; Vicente S. Fuertes-Miquel; Óscar E. Coronado-Hernández; Román Ponz-Carcelén; Francisco Biel-Sanchis. Analysis of hydraulic transients during pipeline filling processes with air valves in large-scale installations. Urban Water Journal 2020, 17, 568 -575.
AMA StyleGuillermo Romero, Vicente S. Fuertes-Miquel, Óscar E. Coronado-Hernández, Román Ponz-Carcelén, Francisco Biel-Sanchis. Analysis of hydraulic transients during pipeline filling processes with air valves in large-scale installations. Urban Water Journal. 2020; 17 (6):568-575.
Chicago/Turabian StyleGuillermo Romero; Vicente S. Fuertes-Miquel; Óscar E. Coronado-Hernández; Román Ponz-Carcelén; Francisco Biel-Sanchis. 2020. "Analysis of hydraulic transients during pipeline filling processes with air valves in large-scale installations." Urban Water Journal 17, no. 6: 568-575.
Frequency analysis of extreme events is used to estimate the maximum rainfall associated with different return periods and is used in planning hydraulic structures. When carrying out this type of analysis in engineering projects, the hydrological distributions that best fit the trend of maximum 24 h rainfall data are unknown. This study collected maximum 24 h rainfall records from 362 stations distributed throughout Colombia, with the goal of guiding hydraulic planners by suggesting the probability distributions they should use before beginning their analysis. The generalized extreme value (GEV) probability distribution, using the weighted moments method, presented the best fits of frequency analysis of maximum daily precipitation for various return periods for selected rainfall stations in Colombia.
Óscar E. Coronado-Hernández; Ernesto Merlano-Sabalza; Zaid Díaz-Vergara; Jairo R. Coronado-Hernández. Selection of Hydrological Probability Distributions for Extreme Rainfall Events in the Regions of Colombia. Water 2020, 12, 1397 .
AMA StyleÓscar E. Coronado-Hernández, Ernesto Merlano-Sabalza, Zaid Díaz-Vergara, Jairo R. Coronado-Hernández. Selection of Hydrological Probability Distributions for Extreme Rainfall Events in the Regions of Colombia. Water. 2020; 12 (5):1397.
Chicago/Turabian StyleÓscar E. Coronado-Hernández; Ernesto Merlano-Sabalza; Zaid Díaz-Vergara; Jairo R. Coronado-Hernández. 2020. "Selection of Hydrological Probability Distributions for Extreme Rainfall Events in the Regions of Colombia." Water 12, no. 5: 1397.
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.
Óscar E. Coronado-Hernández; Vicente S. Fuertes-Miquel; Daniel Mora-Meliá; Yamisleydi Salgueiro. Quasi-static Flow Model for Predicting the Extreme Values of Air Pocket Pressure in Draining and Filling Operations in Single Water Installations. Water 2020, 12, 664 .
AMA StyleÓscar E. Coronado-Hernández, Vicente S. Fuertes-Miquel, Daniel Mora-Meliá, Yamisleydi Salgueiro. Quasi-static Flow Model for Predicting the Extreme Values of Air Pocket Pressure in Draining and Filling Operations in Single Water Installations. Water. 2020; 12 (3):664.
Chicago/Turabian StyleÓscar E. Coronado-Hernández; Vicente S. Fuertes-Miquel; Daniel Mora-Meliá; Yamisleydi Salgueiro. 2020. "Quasi-static Flow Model for Predicting the Extreme Values of Air Pocket Pressure in Draining and Filling Operations in Single Water Installations." Water 12, no. 3: 664.
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.
G. Romero; O.E. Coronado-Hernández; V.S. Fuertes-Miquel; R. Ponz-Carcelén. Maniobras de llenado y vaciado en grandes conducciones. Aplicación a una tubería de fundición DN400 en Massamagrell (Valencia, España). Ingeniería del agua 2020, 24, 15 -29.
AMA StyleG. Romero, O.E. Coronado-Hernández, V.S. Fuertes-Miquel, R. Ponz-Carcelén. Maniobras de llenado y vaciado en grandes conducciones. Aplicación a una tubería de fundición DN400 en Massamagrell (Valencia, España). Ingeniería del agua. 2020; 24 (1):15-29.
Chicago/Turabian StyleG. Romero; O.E. Coronado-Hernández; V.S. Fuertes-Miquel; R. Ponz-Carcelén. 2020. "Maniobras de llenado y vaciado en grandes conducciones. Aplicación a una tubería de fundición DN400 en Massamagrell (Valencia, España)." Ingeniería del agua 24, no. 1: 15-29.
Oscar E. Coronado-Hernández; Vicente S. Fuertes-Miquel; Mohsen Besharat; Helena M. Ramos. Modelo numérico del proceso de llenado de una conducción simple con válvula de aire. Revista Recursos Hídricos 2019, 40, 19 -25.
AMA StyleOscar E. Coronado-Hernández, Vicente S. Fuertes-Miquel, Mohsen Besharat, Helena M. Ramos. Modelo numérico del proceso de llenado de una conducción simple con válvula de aire. Revista Recursos Hídricos. 2019; 40 (2):19-25.
Chicago/Turabian StyleOscar E. Coronado-Hernández; Vicente S. Fuertes-Miquel; Mohsen Besharat; Helena M. Ramos. 2019. "Modelo numérico del proceso de llenado de una conducción simple con válvula de aire." Revista Recursos Hídricos 40, no. 2: 19-25.
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.
Óscar E. Coronado-Hernández; Mohsen Besharat; Vicente S. Fuertes-Miquel; Helena M. Ramos. Effect of a Commercial Air Valve on the Rapid Filling of a Single Pipeline: a Numerical and Experimental Analysis. Water 2019, 11, 1814 .
AMA StyleÓscar E. Coronado-Hernández, Mohsen Besharat, Vicente S. Fuertes-Miquel, Helena M. Ramos. Effect of a Commercial Air Valve on the Rapid Filling of a Single Pipeline: a Numerical and Experimental Analysis. Water. 2019; 11 (9):1814.
Chicago/Turabian StyleÓscar E. Coronado-Hernández; Mohsen Besharat; Vicente S. Fuertes-Miquel; Helena M. Ramos. 2019. "Effect of a Commercial Air Valve on the Rapid Filling of a Single Pipeline: a Numerical and Experimental Analysis." Water 11, no. 9: 1814.
Mohsen Besharat; Oscar Enrique Coronado-Hernández; Vicente Samuel Fuertes-Miquel; Maria Teresa Viseu; Helena Margarida Ramos. Computational fluid dynamics for sub-atmospheric pressure analysis in pipe drainage. Journal of Hydraulic Research 2019, 58, 553 -565.
AMA StyleMohsen Besharat, Oscar Enrique Coronado-Hernández, Vicente Samuel Fuertes-Miquel, Maria Teresa Viseu, Helena Margarida Ramos. Computational fluid dynamics for sub-atmospheric pressure analysis in pipe drainage. Journal of Hydraulic Research. 2019; 58 (4):553-565.
Chicago/Turabian StyleMohsen Besharat; Oscar Enrique Coronado-Hernández; Vicente Samuel Fuertes-Miquel; Maria Teresa Viseu; Helena Margarida Ramos. 2019. "Computational fluid dynamics for sub-atmospheric pressure analysis in pipe drainage." Journal of Hydraulic Research 58, no. 4: 553-565.
Filling and emptying processes are common maneuvers while operating, controlling and managing water pipeline systems. Currently, these operations are executed following recommendations from technical manuals and pipe manufacturers; however, these recommendations have a lack of understanding about the behavior of these processes. The application of mathematical models considering transient flows with entrapped air pockets is necessary because a rapid filling operation can cause pressure surges due to air pocket compressions, while an uncontrolled emptying operation can generate troughs of sub-atmospheric pressure caused by air pocket expansion. Depending on pipe and installation conditions, either situation can produce a rupture of pipe systems. Recently, reliable mathematical models have been developed by different researchers. This paper reviews and compares various mathematical models to simulate these processes. Water columns can be analyzed using a rigid water column model, an elastic water model, or 2D/3D CFD models; air–water interfaces using a piston-flow model or more complex models; air pockets through a polytropic model; and air valves using an isentropic nozzle flow or similar approaches. This work can be used as a starting point for planning filling and emptying operations in pressurized pipelines. Uncertainties of mathematical models of two-phases flow concerning to a non-variable friction factor, a polytropic coefficient, an air pocket sizes and an air valve behavior are identified.
Vicente S. Fuertes-Miquel; Oscar E. Coronado-Hernández; Daniel Mora-Meliá; Pedro L. Iglesias-Rey. Hydraulic modeling during filling and emptying processes in pressurized pipelines: a literature review. Urban Water Journal 2019, 16, 299 -311.
AMA StyleVicente S. Fuertes-Miquel, Oscar E. Coronado-Hernández, Daniel Mora-Meliá, Pedro L. Iglesias-Rey. Hydraulic modeling during filling and emptying processes in pressurized pipelines: a literature review. Urban Water Journal. 2019; 16 (4):299-311.
Chicago/Turabian StyleVicente S. Fuertes-Miquel; Oscar E. Coronado-Hernández; Daniel Mora-Meliá; Pedro L. Iglesias-Rey. 2019. "Hydraulic modeling during filling and emptying processes in pressurized pipelines: a literature review." Urban Water Journal 16, no. 4: 299-311.
In Colombia, daily maximum multiannual series are one of the main inputs for design streamflow calculation, which requires performing a rainfall frequency analysis that involves several prior steps: (a) requesting the datasets, (b) waiting for the information, (c) reviewing the datasets received for missing or data different from the requested variable, and (d) requesting the information once again if it is not correct. To tackle these setbacks, 318 rain gauges located in the Colombian Caribbean region were used to first evaluate whether or not the Gumbel distribution was indeed the most suitable by performing frequency analyses using three different distributions (Gumbel, Generalized Extreme Value (GEV), and Log-Pearson 3 (LP3)); secondly, to generate daily maximum isohyetal maps for return periods of 2, 5, 10, 20, 25, 50, and 100 years; and, lastly, to evaluate which interpolation method (IDW, spline, and ordinary kriging) works best in areas with a varying density of data points. GEV was most suitable in 47.2% of the rain gauges, while Gumbel, in spite of being widely used in Colombia, was only suitable in 34.3% of the cases. Regarding the interpolation method, better isohyetals were obtained with the IDW method. In general, the areal maximum daily rainfall estimated showed good agreement when compared to the true values.
Álvaro González-Álvarez; Orlando M. Viloria-Marimón; Óscar E. Coronado-Hernández; Andrés M. Vélez-Pereira; Kibrewossen Tesfagiorgis; Jairo R. Coronado-Hernández. Isohyetal Maps of Daily Maximum Rainfall for Different Return Periods for the Colombian Caribbean Region. Water 2019, 11, 358 .
AMA StyleÁlvaro González-Álvarez, Orlando M. Viloria-Marimón, Óscar E. Coronado-Hernández, Andrés M. Vélez-Pereira, Kibrewossen Tesfagiorgis, Jairo R. Coronado-Hernández. Isohyetal Maps of Daily Maximum Rainfall for Different Return Periods for the Colombian Caribbean Region. Water. 2019; 11 (2):358.
Chicago/Turabian StyleÁlvaro González-Álvarez; Orlando M. Viloria-Marimón; Óscar E. Coronado-Hernández; Andrés M. Vélez-Pereira; Kibrewossen Tesfagiorgis; Jairo R. Coronado-Hernández. 2019. "Isohyetal Maps of Daily Maximum Rainfall for Different Return Periods for the Colombian Caribbean Region." Water 11, no. 2: 358.
The prediction of the pressure inside the air pocket in water pipelines has been the topic for a lot of research works. Several aspects in this field have been discussed, such as the filling and the emptying procedures. The emptying process can affect the safety and the efficiency of water systems. Current research presents an analysis of the emptying process using experimental and computational results. The phenomenon is simulated using the two-dimensional computational fluid dynamics (2D CFD) and the one-dimensional mathematical (1D) models. A backflow air analysis is also provided based on CFD simulations. The developed models show good ability in the prediction of the sub-atmospheric pressure and the flow velocity in the system. In most of the cases, the 1D and 2D CFD models show similar performance in the prediction of the pressure and the velocity results. The backflow air development can be accurately explained using the CFD model.
Mohsen Besharat; Oscar E. Coronado-Hernández; Vicente S. Fuertes-Miquel; Maria Teresa Viseu; Helena M. Ramos. Backflow air and pressure analysis in emptying a pipeline containing an entrapped air pocket. Urban Water Journal 2018, 15, 769 -779.
AMA StyleMohsen Besharat, Oscar E. Coronado-Hernández, Vicente S. Fuertes-Miquel, Maria Teresa Viseu, Helena M. Ramos. Backflow air and pressure analysis in emptying a pipeline containing an entrapped air pocket. Urban Water Journal. 2018; 15 (8):769-779.
Chicago/Turabian StyleMohsen Besharat; Oscar E. Coronado-Hernández; Vicente S. Fuertes-Miquel; Maria Teresa Viseu; Helena M. Ramos. 2018. "Backflow air and pressure analysis in emptying a pipeline containing an entrapped air pocket." Urban Water Journal 15, no. 8: 769-779.
Emptying pipelines can be critical in many water distribution networks because subatmospheric pressure troughs could cause considerable damage to the system due to the expansion of entrapped air. Researchers have given relatively little attention to emptying processes compared to filling processes. The intricacy of computations of this phenomenon makes it difficult to predict the behaviour during emptying, and there are only a few reliable models in the literature. In this work, a computational model for simulating the transient phenomena in single pipes is proposed, and was validated using experimental results. The proposed model is based on a rigid column to analyse water movement, the air–water interface, and air pocket equations. Two practical cases were used to validate the model: (1) a single pipe with the upstream end closed, and (2) a single pipe with an air valve installed on the upstream end. The results show how the model accurately predicts the experimental data, including the pressure oscillation patterns and subatmospheric pressure troughs.
Vicente S. Fuertes-Miquel; Oscar E. Coronado-Hernández; Pedro L. Iglesias-Rey; Daniel Mora-Meliá. Transient phenomena during the emptying process of a single pipe with water–air interaction. Journal of Hydraulic Research 2018, 57, 318 -326.
AMA StyleVicente S. Fuertes-Miquel, Oscar E. Coronado-Hernández, Pedro L. Iglesias-Rey, Daniel Mora-Meliá. Transient phenomena during the emptying process of a single pipe with water–air interaction. Journal of Hydraulic Research. 2018; 57 (3):318-326.
Chicago/Turabian StyleVicente S. Fuertes-Miquel; Oscar E. Coronado-Hernández; Pedro L. Iglesias-Rey; Daniel Mora-Meliá. 2018. "Transient phenomena during the emptying process of a single pipe with water–air interaction." Journal of Hydraulic Research 57, no. 3: 318-326.
An air pocket’s behaviour inside of a pipeline during transient conditions is of great importance due to its effect on the safety of the hydraulic system and the complexity of modeling its behaviour. The emptying process from water pipelines needs more assessment because the generation of troughs of subatmospheric pressure may lead to serious damage. This research studies the air pocket parameters during an emptying process from a water pipeline. A well-equipped experimental facility was used to measure the pressure and the velocity change throughout the water emptying for different air pocket sizes and valve opening times. The phenomenon was simulated using a one-dimensional (1D) developed model based on the rigid formulation with a non-variable friction factor and a constant pipe diameter. The mathematical model shows good ability in predicting the trough of subatmospheric pressure value as the most important parameter which can affect the safety of hydraulic systems.
Oscar E. Coronado-Hernández; Vicente S. Fuertes-Miquel; Mohsen Besharat; Helena M. Ramos. Subatmospheric pressure in a water draining pipeline with an air pocket. Urban Water Journal 2018, 15, 346 -352.
AMA StyleOscar E. Coronado-Hernández, Vicente S. Fuertes-Miquel, Mohsen Besharat, Helena M. Ramos. Subatmospheric pressure in a water draining pipeline with an air pocket. Urban Water Journal. 2018; 15 (4):346-352.
Chicago/Turabian StyleOscar E. Coronado-Hernández; Vicente S. Fuertes-Miquel; Mohsen Besharat; Helena M. Ramos. 2018. "Subatmospheric pressure in a water draining pipeline with an air pocket." Urban Water Journal 15, no. 4: 346-352.
The 24-h maximum rainfall (P24h-max) observations recorded at the synoptic weather station of Rafael Núñez airport (Cartagena de Indias, Colombia) were analyzed, and a linear increasing trend over time was identified. It was also noticed that the occurrence of the rainfall value (over the years of record) for a return period of 10 years under stationary conditions (148.1 mm) increased, which evidences a change in rainfall patterns. In these cases, the typical stationary frequency analysis is unable to capture such a change. So, in order to further evaluate rainfall observations, frequency analyses of P24h-max for stationary and non-stationary conditions were carried out (by using the generalized extreme value distribution). The goodness-of-fit test of Akaike Information Criterion (AIC), with values of 753.3721 and 747.5103 for stationary and non-stationary conditions respectively, showed that the latter best depicts the increasing rainfall pattern. Values of rainfall were later estimated for different return periods (2, 5, 10, 25, 50, and 100 years) to quantify the increase (non-stationary versus stationary condition), which ranged 6% to 12% for return periods from 5 years to 100 years, and 44% for a 2-year return period. The effect of these findings were tested in the Gordo creek watershed by first calculating the resulting direct surface runoff (DSR) for various return periods, and then modeling the hydraulic behavior of the downstream area (composed of a 178.5-m creek’s reach and an existing box-culvert located at the watershed outlet) that undergoes flooding events every year. The resulting DSR increase oscillated between 8% and 19% for return periods from 5 to 100 years, and 77% for a 2-year return period when the non-stationary and stationary scenarios were compared. The results of this study shed light upon to the precautions that designers should take when selecting a design, based upon rainfall observed, as it may result in an underestimation of both the direct surface runoff and the size of the hydraulic structures for runoff and flood management throughout the city.
Álvaro González-Álvarez; Oscar E. Coronado-Hernández; Vicente S. Fuertes-Miquel; Helena M. Ramos. Effect of the Non-Stationarity of Rainfall Events on the Design of Hydraulic Structures for Runoff Management and Its Applications to a Case Study at Gordo Creek Watershed in Cartagena de Indias, Colombia. Fluids 2018, 3, 27 .
AMA StyleÁlvaro González-Álvarez, Oscar E. Coronado-Hernández, Vicente S. Fuertes-Miquel, Helena M. Ramos. Effect of the Non-Stationarity of Rainfall Events on the Design of Hydraulic Structures for Runoff Management and Its Applications to a Case Study at Gordo Creek Watershed in Cartagena de Indias, Colombia. Fluids. 2018; 3 (2):27.
Chicago/Turabian StyleÁlvaro González-Álvarez; Oscar E. Coronado-Hernández; Vicente S. Fuertes-Miquel; Helena M. Ramos. 2018. "Effect of the Non-Stationarity of Rainfall Events on the Design of Hydraulic Structures for Runoff Management and Its Applications to a Case Study at Gordo Creek Watershed in Cartagena de Indias, Colombia." Fluids 3, no. 2: 27.
This paper presents a mathematical model for analyzing the emptying process in a pipeline using pressurized air. The rigid water column model (RWCM) is used to analyze the transient phenomena that occur during the emptying of the pipeline. The air-water interface is also computed in the proposed model. The proposed model is applied along a 271.6-m-long PVC-steel pipeline with a 232-mm internal diameter. The boundary conditions are given by a high-pressure air tank at the upstream end and a manual butterfly valve at the downstream end. The solution was carried out in a computer modeling program. The results show that comparisons between both the computed and measured water flow oscillations and gauge pressures are very similar; hence, the model can effectively simulate the transient flow in this system. In addition, the results indicate that the proposed model can predict both the water flow and gauge pressure better than previous models.
Oscar E. Coronado-Hernández; Vicente S. Fuertes-Miquel; Pedro L. Iglesias-Rey; Francisco J. Martínez-Solano. Rigid Water Column Model for Simulating the Emptying Process in a Pipeline Using Pressurized Air. Journal of Hydraulic Engineering 2018, 144, 06018004 .
AMA StyleOscar E. Coronado-Hernández, Vicente S. Fuertes-Miquel, Pedro L. Iglesias-Rey, Francisco J. Martínez-Solano. Rigid Water Column Model for Simulating the Emptying Process in a Pipeline Using Pressurized Air. Journal of Hydraulic Engineering. 2018; 144 (4):06018004.
Chicago/Turabian StyleOscar E. Coronado-Hernández; Vicente S. Fuertes-Miquel; Pedro L. Iglesias-Rey; Francisco J. Martínez-Solano. 2018. "Rigid Water Column Model for Simulating the Emptying Process in a Pipeline Using Pressurized Air." Journal of Hydraulic Engineering 144, no. 4: 06018004.
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.
Oscar E. Coronado-Hernández; Vicente S. Fuertes-Miquel; Fredy N. Angulo-Hernández. Emptying Operation of Water Supply Networks. Water 2017, 10, 22 .
AMA StyleOscar E. Coronado-Hernández, Vicente S. Fuertes-Miquel, Fredy N. Angulo-Hernández. Emptying Operation of Water Supply Networks. Water. 2017; 10 (1):22.
Chicago/Turabian StyleOscar E. Coronado-Hernández; Vicente S. Fuertes-Miquel; Fredy N. Angulo-Hernández. 2017. "Emptying Operation of Water Supply Networks." Water 10, no. 1: 22.
The emptying procedure is a common operation that engineers have to face in pipelines. This generates subatmospheric pressure caused by the expansion of air pockets, which can produce the collapse of the system depending on the conditions of the installation. To avoid this problem, engineers have to install air valves in pipelines. However, if air valves are not adequately designed, then the risk in pipelines continues. In this research, a mathematical model is developed to simulate an emptying process in pipelines that can be used for planning this type of operation. The one-dimensional proposed model analyzes the water phase propagation by a new rigid model and the air pockets effect using thermodynamic formulations. The proposed model is validated through measurements of the air pocket absolute pressure, the water velocity and the length of the emptying columns in an experimental facility. Results show that the proposed model can accurately predict the hydraulic characteristic variables.
Oscar E. Coronado-Hernández; Vicente S. Fuertes-Miquel; Mohsen Besharat; Helena M. Ramos. Experimental and Numerical Analysis of a Water Emptying Pipeline Using Different Air Valves. Water 2017, 9, 98 .
AMA StyleOscar E. Coronado-Hernández, Vicente S. Fuertes-Miquel, Mohsen Besharat, Helena M. Ramos. Experimental and Numerical Analysis of a Water Emptying Pipeline Using Different Air Valves. Water. 2017; 9 (2):98.
Chicago/Turabian StyleOscar E. Coronado-Hernández; Vicente S. Fuertes-Miquel; Mohsen Besharat; Helena M. Ramos. 2017. "Experimental and Numerical Analysis of a Water Emptying Pipeline Using Different Air Valves." Water 9, no. 2: 98.