Lewis A. Rossman’s research while affiliated with The Ohio Environmental Protection Agency and other places

This work compares several alternative methods of pressure-driven analysis (PDA) implemented within the code base of the EPANET water distribution system modeling software. The resulting code includes a direct method, the original and a newly modified version of the inverse method currently used by EPANET 2.2, and two recently published methods (the global gradient approach-based PDA and the active set method). The latter four methods solve PDA problems using an inverse flow–pressure relationship, whereas the direct method uses the original relationship. The alternative methods were extensively tested, and their performance was compared over several case study water distribution networks of vastly different sizes and complexities. The results showed that all of the new inverse methods are equally efficient and reliable, whereas the direct method is less reliable by having a higher frequency of failing to converge. HIGHLIGHTS A demand-driven approach and five alternative PDAs were incorporated into EPANET.; The EPANET 2.2 barrier function algorithm was modified to improve convergence, a direct PDA and the inverse global gradient approach-based PDA and ASM approaches were also included.; The code, thoroughly tested on the available water distribution network, cases up to over 150,000 nodes, will be made available for further comparisons.; Results confirm the lack of convergence of the direct approach.;

Ce fichier compressé contient: - Le programme d’installation d’EPANET 2.00.12 en française - Le fichier des mises à jour jusqu’à la version 2.00.12. La version française 2.00.12 relie pour le moment avec la Boîte à Outils originale en anglais de cette même version.

Este fichero comprimido contiene: - El instalador de EPANET 2.00.12 en Español - El fichero de actualizaciones hasta la versión 2.00.12. La versión española 2.00.12 enlaza por ahora con la Toolkit original en inglés de esta misma versión

Para descargar el INSTALADOR de la versión 2.00.12 Esp, ir a la pestaña 'Linded data' más abajo......... En la revisión de este Manual de Mayo de 2017, se han actualizado algunas opciones incorporadas en la versión 2.00.12, y se ha añadido un índice lateral para facilitar las consultas. Además se ha extendido el Manual, para incorporar en el apéndice D las instrucciones de manejo del Módulo de Herramientas, junto a algunos ejemplos, el cual es utilizado cada vez más por los programadores que quieren incorporar la potencia de cálculo de EPANET en sus propias aplicaciones, o por los investigadores que lo utilizan para ir más lejos creando nuevas aplicaciones. Dichas instrucciones ya residían en el fichero de Ayuda del Módulo de cálculo, y simplemente se han trasladado a la nueva versión del Manual para facilitar su manejo. Además se han añadido instrucciones concretas para construir los diferentes ejemplos en los distintos entornos de programación, comenzando desde cero.

Pour télécharger l'INSTALLATEUR de la version 2.00.12 Fr, allez à l’onglet 'Linked data' ci-dessous ......... Dans la révision de ce manuel, fait en mai 2017, ils ont été mis à jour certaines options ajoutés à la version 2.00.12, et un indice latéral a été ajouté pour faciliter la consultation. Il a également étendu le manuel pour incorporer dans l’appendice D les instructions d'utilisation de la Boîte à Outils avec des exemples, de plus en plus utilisé par les programmeurs qui veulent intégrer la puissance de calcul de EPANET dans leurs propres applications, ou les chercheurs qui l'utilisent pour aller plus loin en créant de nouvelles applications. Ces instructions résidant déjà dans le fichier d'aide du module de calcul, simplement se sont ajoutées vers la nouvelle version du manuel pour faciliter l’utilisation. Nous avons également ajouté des instructions spécifiques pour la construction des différents exemples dans différents environnements de programmation, à partir de zéro.

A reliable source of clean, drinkable water is a must for any city or community to survive and prosper. We take for granted the clean, drinkable water delivered from the tap whenever we want to quench that thirst. But few people recognize or understand the complexity of our nation’s water system and what goes into the operations required to deliver this essential human need in an unfailing way, day in and day out. As one of our nation’s critical infrastructures, water distribution systems face security threats ranging from natural disasters, like hurricanes and extreme weather, to intentional acts of sabotage or terrorism. Obviously, it’s important to be able to quickly detect, assess, and respond to any kind of water contamination event no matter the source. But in order to do that, it is essential to have a real-time understanding of what is going on in the water distribution system. This would help water utilities be better prepared to respond to natural disasters or intentional acts of sabotage and could also alert them to other problems like leaks in the distribution system or water quality problems. So how do we get a real-time understanding of water system operations? We integrate a utility’s infrastructure model with their real-time or Supervisory Control and Data Acquisition (SCADA) data. We are testing and evaluating our real-time modeling software tools at the Northern Kentucky Water District (NKWD). We are demonstrating how our real-time modeling software tools can be used to provide water utility operators with a better understanding of their water system and its operation. With our software tools, utility operators will have a “flight simulator” type of capability which will allow them to be better prepared to respond to emergencies and plan for the future. To gain this understanding of the water system, we have developed an object-oriented software library called EPANET-RTX (EPANET “Real-Time eXtension”). RTX, for short, joins operational data from an already existing data system with an infrastructure model to improve operations and enhance security in a more sustainable and productive manner. RTX is built on the industry standard for distribution system modeling, EPANET, and leverages years of real-time modeling research and development efforts conducted by EPA. RTX is open source software, and you can find it here. By making it open source, EPA hopes commercial companies will evaluate the technology and use it to develop commercial products. We will continue to develop the RTX libraries which the water community will be able to use to (1) help water utilities field verify (validate) their infrastructure models and (2) develop RTX-based applications. These RTX-based applications will enable water utilities to better manage, operate, and secure their water systems. To learn more about EPA’s research to keep our water systems safe and secure, please visit: epa.gov/nhsrc.

The known formulations for steady-state hydraulics within looped water distribution networks are rederived in terms of linear and nonlinear transformations of the original set of partly linear and partly nonlinear equations that express conservation of mass and energy. All of these formulations lead to a system of nonlinear equations that can be linearized as a function of the chosen unknowns using either the Newton-Raphson (NR) or the linear theory (LT) approaches. This produces a number of different algorithms, some of which are already known in the literature, whereas others have been originally developed within this work. For the sake of clarity, all the different algorithms were rederived using the same analytical approach and a unified notation. They were all applied to the same test case network with randomly perturbed demands to compare their convergence characteristics. The results show that all of the linearly transformed formulations have exactly the same convergence rate, whose value depends on whether a NR or LT algorithm was used, and that they converge faster than the nonlinearly transformed formulations do. A number of computational factors suggest that the global algorithm, in either its NR or LT form, is the most attractive of the various formulations to implement. DOI:10.1061/(ASCE)HY.1943-7900.0000703. (C) 2013 American Society of Civil Engineers.

EPANET is a widely used public domain software package for modeling the hydraulic and water quality behavior of water distribution systems over an extended period of time. The last major update to the code was version 2.0 released in 2000 (Rossman, 2000). Since that time there have been many useful advancements made in water distribution system modeling, many of which have been presented at past WDSA symposia. Several of these are being incorporated into an updated version of EPANET. Hydraulic modeling improvements include more efficient sparse matrix solution routines, the modeling of pressure deficient/dependent demands, more versatile options for controlling pump and valve settings, and improved stability for extended period analysis. Water quality enhancements include non-ideal mixing at pipe junctions, longitudinal dispersion within pipes, and more efficient implementation of the constituent transport procedure within pipes. In addition, several options for re-writing EPANET's graphical user interface in a more user accessible language and platform-independent manner are being explored.

The EPA Storm Water Management Model (SWMM) is a widely used program for simulating urban runoff quantity and quality. Its existing documentation includes a User's Manual that describes how to run the program and a Reference Manual that covers its theory and algorithms. A new manual, the ''SWMM Applications Manual'', has been added to this collection. It contains nine worked-out examples addressing common stormwater management and design problems encountered in practice. The manual will be especially useful for new SWMM users who need additional guidance in applying this powerful tool to urban drainage design and analysis.