Water and wastewater conveyance research is steeply based in advancements of numerical methods and models. Design engineers need more than refinements in analysis methods to evolve the standards of practice and the related design guidelines. In an effort to improve the design efficiency and operating reliability of pipeline systems, design guidelines have been developed to enfold the various technological advancements and elevate the standard of care used in the pipeline design process. In this respect, the guidelines have been successful. However, design engineers, manufacturers, and owners have developed a level of dependency on the success of the guidelines. The guidelines, which were developed as and are clearly still held to be by the various publishing associations, a minimum standard of care, have become the default standard of care. Such statements are, of course, gross generalizations, but this thesis is dedicated to move the standard of care forward through an integrated design approach that provides a roadmap to inter-relate the independent design guidelines into a composite design approach based on hydrodynamic loading. Hydrodynamic loading introduces of a temporal parameter into the design process. With the temporal parameter this work demonstrates how the consideration of both the frequency and the influence of acceleration head on the magnitude of the hydraulic loading can be used to integrate and evolve the individual component designs into a more efficient, cost effective, reliable composite design result. With a temporal parameter present in design, many opportunities present themselves to advance the current design procedures outlined in the present design guidelines. This thesis identifies some of the present shortcomings found in the modern pipeline and appurtenance design standards and introduces a recommended path forward. Specific changes to the present standards are proposed in this work and a unique analysis procedure to identify the failure potential of cement mortar lining has been developed. Introducing the integrated design approach will allow for a significant evolution to the present standard of practice in water and wastewater conveyance system designs.

Water and wastewater conveyance research is steeply based in advancements of numerical methods and models. Design engineers need more than refinements in analysis methods to evolve the standards of practice and the related design guidelines. In an effort to improve the design efficiency and operating reliability of pipeline systems, design guidelines have been developed to enfold the various technological advancements and elevate the standard of care used in the pipeline design process. In this respect, the guidelines have been successful. However, design engineers, manufacturers, and owners have developed a level of dependency on the success of the guidelines. The guidelines, which were developed as and are clearly still held to be by the various publishing associations, a minimum standard of care, have become the default standard of care. Such statements are, of course, gross generalizations, but this thesis is dedicated to move the standard of care forward through an integrated design approach that provides a roadmap to inter-relate the independent design guidelines into a composite design approach based on hydrodynamic loading. Hydrodynamic loading introduces of a temporal parameter into the design process. With the temporal parameter this work demonstrates how the consideration of both the frequency and the influence of acceleration head on the magnitude of the hydraulic loading can be used to integrate and evolve the individual component designs into a more efficient, cost effective, reliable composite design result. With a temporal parameter present in design, many opportunities present themselves to advance the current design procedures outlined in the present design guidelines. This thesis identifies some of the present shortcomings found in the modern pipeline and appurtenance design standards and introduces a recommended path forward. Specific changes to the present standards are proposed in this work and a unique analysis procedure to identify the failure potential of cement mortar lining has been developed. Introducing the integrated design approach will allow for a significant evolution to the present standard of practice in water and wastewater conveyance system designs.

Tesis por compendio / [ES] El análisis de los fenómenos transitorios durante las operaciones de llenado en conducciones de agua ha sido estudiado de manera detallada comparado con las maniobras de vaciado. En este último se encontró que no existen modelos matemáticos capaces de predecir el fenómeno. Esta investigación inicia estudiando el fenómeno transitorio generado durante el vaciado en una tubería simple, como paso previo para entender el comportamiento de las variables hidráulicas y termodinámicas durante el vaciado de agua en conducciones presurizadas de perfil irregular. Los análisis son realizados considerando dos situaciones: (i) la situación No. 1 corresponde al caso donde no hay válvulas de aire instaladas o cuando éstas han fallado por problemas operacionales o de mantenimiento, que representa la condición más desfavorable con respecto a la depresión máxima alcanzada; y (ii) la situación No. 2 corresponde al caso en donde se han instalado válvulas de aire en los puntos más elevados de la conducción para dar fiabilidad mediante el aire introducido al sistema previniendo de esta manera la depresión máxima. En esta tesis doctoral se ha desarrollado un modelo matemático para predecir el comportamiento de las operaciones de vaciado. El modelo matemático es propuesto para las dos situaciones mencionadas anteriormente. La fase líquida (agua) es simulada con un modelo de columna rígida, en el cual se desprecia la elasticidad del agua y de la tubería debido a que la elasticidad del aire es mucho mayor que estas; y la interfaz aire-agua es modelada con un modelo de flujo pistón, el cual asume que la columna de agua es perpendicular a la dirección principal del flujo. La fase de aire es modelada usando tres ecuaciones: (a) un modelo politrópico basado en el comportamiento energético, que considera la expansión de las bolsas de aire; (b) la formulación de las válvulas de aire para cuantificar la magnitud del caudal de aire admitido; y (c) la ecuación de continuidad de la bolsa de aire. Un sistema ordinario de ecuaciones diferenciales es solucionado utilizando la herramienta de Simulink de Matlab. El modelo matemático es validado empleando bancos experimentales localizados en los laboratorios de hidráulica de la Universitat Politècnica de València (Valencia, España) y en el Instituto Superior Técnico de la Universidad de Lisboa (Lisboa, Portugal). Los resultados muestran que el modelo matemático predice adecuadamente los datos experimentales de las presiones de las bolsas de aire, las velocidades del agua y las longitudes de las columnas de agua. Finalmente, el modelo matemático es aplicado a un caso de estudio para mostrar su aplicabilidad a situaciones prácticas, con el fin de poder ser empleado por ingenieros para estudiar el fenómeno en conducciones reales y así tomar decisiones acerca de la planificación de esta operación. / [CA] L'anàlisi dels fenòmens transitoris durant les operacions d'ompliment en conduccions d'aigua ha sigut estudiat de manera detallada comparat amb les maniobres de buidatge. En este últim es va trobar que no hi ha models matemàtics capaços de predir el fenomen. Esta investigació inicia estudiant el fenomen transitori generat durant el buidatge en una canonada simple, com a pas previ per a entendre el comportament de les variables hidràuliques i termodinàmiques durant el buidatge d'aigua en conduccions pressuritzades de perfil irregular. Les anàlisis són realitzats considerant dos situacions: (i) la situació No. 1 correspon al cas on no hi ha vàlvules d'aire instal·lades o quan estes han fallat per problemes operacionals o de manteniment, que representa la condició més desfavorable respecte a la depressió màxima aconseguida; i (ii) la situació No. 2 correspon al cas on s'han instal·lat vàlvules d'aire en els punts més elevats de la conducció per a donar fiabilitat per mitjà de l'aire introduït al sistema prevenint d'esta manera la depressió màxima. En esta tesi doctoral s'ha desenrotllat un model matemàtic per a predir el comportament de les operacions de buidatge. El model matemàtic és proposat per a les dos situacions mencionades anteriorment. La fase líquida (aigua) és simulada amb un model de columna rígida, en el qual es desprecia l'elasticitat de l'aigua i de la canonada pel fet que l'elasticitat de l'aire és molt major que estes; i la interfície aire-aigua és modelada amb un model de flux pistó, el qual assumix que la columna d'aigua és perpendicular a la direcció principal del flux. La fase d'aire és modelada usant tres equacions: (a) un model politròpic basat en el comportament energètic, que considera l'expansió de les bosses d'aire; (b) la formulació de les vàlvules d'aire per a quantificar la magnitud del cabal d'aire admés; i (c) l'equació de continuïtat de la bossa d'aire. Un sistema ordinari d'equacions diferencials és solucionat utilitzant la ferramenta de Simulink de Matlab. El model matemàtic és validat emprant bancs experimentals localitzats en els laboratoris d'hidràulica de la Universitat Politècnica de València (València, Espanya) i en l'Institut Superior Tècnic de la Universitat de Lisboa (Lisboa, Portugal). Els resultats mostren que el model matemàtic prediu adequadament les dades experimentals de les pressions de les bosses d'aire, les velocitats de l'aigua i les longituds de les columnes d'aigua. Finalment, el model matemàtic és aplicat a un cas d'estudi per a mostrar la seua aplicabilitat a situacions pràctiques, a fi de poder ser empleat per enginyers per a estudiar el fenomen en conduccions reals i així prendre decisions sobre la planificació d'esta operació. / [EN] The analysis of transient phenomena during water filling operations in pipelines of irregular profiles has been studied much more compared to emptying maneuvers. In the literature, there is a lack of knowledge about mathematical models of emptying operations. This research starts with the analysis of a transient phenomenon during emptying maneuvers in single pipelines, which is a previous stage to understand the emptying operation in pipelines of irregular profiles. Analysis are conducted under two typical situations: (i) one corresponding to either the situation where there are no air valves installed or when they have failed due to operational and maintenance problems which represents the worse condition due to causing the lowest troughs of subatmospheric pressure, and (ii) the other one corresponding to the situation where air valves have been installed at the highest point of hydraulic installations to give reliability by admitting air into the pipelines for preventing troughs of subatmospheric pressure. Particularly, this research developed a mathematical model to predict the behavior of the emptying operations. The mathematical model is proposed for the two aforementioned situations. The liquid phase (water) is simulated using a rigid water column model (RWCM), which neglects the pipe and water elasticity given that the elasticity of the entrapped air pockets is much higher than the one from the pipe and the water. The air-water interface is simulated with a piston flow model assuming that the water column is perpendicular with the main direction of the flow. Gas phase is modeled using three formulations: (a) a polytropic model based on its energetic behavior, which considers an expansion of air pockets; (b) an air valve characterization to quantify the magnitude of admitted air flow; and (c) a continuity equation of the air. An ordinary differential equations system is solved using the Simulink tool of Matlab. The proposed model has been validated using experimental facilities at the hydraulic laboratories of the Universitat Politècnica de València, Valencia, Spain, and the Instituto Superior Técnico, University of Lisbon, Lisbon, Portugal. The results show how the mathematical model adequately predicts the experimental data, including the pressure oscillation patterns, the water velocities, and the lengths of the water columns. Finally, the mathematical model is applied to a case study to show a practical application, which can be used for engineers to study the phenomenon in real pipelines to make decisions about performing of the emptying operation. / Coronado Hernández, ÓE. (2019). Transient phenomena during the emptying process of water in pressurized pipelines [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/120024 / Compendio

The master´s thesis focuses on the behavior of the siphon turbine during unsteady flow. There are two possible conditions. The first condition involves commissioning the turbine. In this situation turbine works like a pump. In the second case, it includes shutting down the turbine by aerating the siphon and thereby breaking the water column. This thesis deals with the second case, where the results of the experiment and the mathematical model are compared.

This diploma thesis deals the formation of water hammer in pipes and the suppress the nega-tive effects especially for the use of protective devices (surge tank, air chamber, air valve and other). The special attention is paid to the use of the air valve, for which it was developed mathematical model. The solution is based on the use of numerical methods Lax-Wendroff with boundary conditions for the air valve.The numerical results are confronted with the ex-periment in conclusion.