Preface

De formigó blanc, ceràmica, acer inoxidable i arbres, mesura 7,02 x 5,13 x 4,44 metres.Bergeron, Valérie (dissenyadora)Pla general de l'obra. consistia en la plantació de tres espècies vegetals al voltant d'una talla mètrica de formigó enrajolada, de set metres d'alçada, que havia de servir per mesurar els diferents ritmes de creixement dels arbres triats

Preface

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groundwater supply and climate change management by means of global atmospheric datasets preliminary results

Abstract Climate change influences hydrological cycle with a direct effect on groundwater resources, one of the most important supply sources for human consumption and irrigation. In a scenario where General Circulation Models do not represent yet a usual tool for water industry managers, potentially the use of global atmospheric datasets is of great interest for evaluating groundwater resources. In this paper data from the European Centre for Medium-Range Weather Forecasts (ECMWF) are compared to local water table measurements. With particular regard to unconfined aquifers, the good correlation between the trend of soil moisture and local water table data is pointed out. Such a promising result authorizes further insights in order to refine reliable tools for evaluating available groundwater resources in a climate change scenario

Editorial

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Numerical and experimental investigation of leaks in viscoelastic pressurized pipe flow

Abstract. This paper extends the analysis concerning the importance in numerical models of unsteady friction and viscoelasticity to transients in plastic pipes with an external flow due to a leak. In fact recently such a benchmarking analysis has been executed for the cases of a constant diameter pipe (Duan et al., 2010), a pipe with a partially closed in-line valve (Meniconi et al., 2012a), and a pipe with cross-section changes in series (Meniconi et al., 2012b). Tests are based on laboratory experiments carried out at the Water Engineering Laboratory (WEL) of the University of Perugia, Italy, and the use of different numerical models. The results show that it is crucial to take into account the viscoelasticity to simulate the main characteristics of the examined transients

Preface: CCWI 2013

Since 1991 "Computing and Control for the Water Industry – CCWI" is a well-established series of bi-annual meetings. On 2–4 September 2013, the 12th edition (CCWI2013) was held in Perugia (Italy) and was focused on Information for Water Systems and Smart Cities. CCWI2013 emphasized the integration between the more conventional themes of the analysis and planning of water systems and information technology. Such an integration offers opportunities for design solutions and innovative models for the challenging problems of water system management in an urban perspective, a key concept for smart cities (Brunone and Giustolisi, 2014). The large number of presentations – more than 200 with many young researchers from Europe and overseas – confirmed the interest for CCWI2013 themes and the increasing success of CCWI Conferences (Fig. 1). This CCWI2013 special issue contains a selection of extended CCWI2013 papers which give a taste of the Proceedings of the Conference published on Procedia Engineering Elsevier (www.sciencedirect.com/science/journal/ 18777058/70). In fact their topics range from sustainabilitybased indicators of the urban water systems (Behzadian et al., 2014), design and control parameters in water treatment (Ramphal and Sibiya, 2014), numerical simulation of the transition between surface and pressurized flow (Fernandez-Pato and Garcia-Navarro, 2014) to optimisation of pump and valve schedules in complex large-scale water distribution networks (Skworcow et al., 2014), and a real data-based model to simulate the behavior of a pumping station equipped with variable speed pumps (Capponi et al., 2014). Figure 1. Last nine editions of CCWI conferences: number of papers published in the proceedings (from Brunone and Giustolisi, 2014)

Pressure Reducing Valve Characterization for Pipe System Management

Abstract Pressure control strategy through Pressure Reducing Valves (PRVs) has been deeply investigated as management strategy, aimed at water leakage reduction avoiding very expensive pipe replacement programmes. On the contrary, few experimental data are available in literature, particularly in unsteady-state conditions. In this paper, the results of some tests carried out at the Water Engineering Laboratory of the University of Perugia (I) in order to characterize a PRV with two set points for high and low pressures are presented. The PRV is installed in a single high-density polyethylene (HDPE) pipe supplied by a tank in which the pressure is assured by pumps of different characteristics. Two types of tests are considered: steady-state tests, to characterize the PRV, and extended period tests, to check its dynamic behaviour

Transient Effects of Self-adjustment of Pressure Reducing Valves

AbstractPressure control strategy through Pressure Reducing Valves (PRV) has been deeply investigated as management strategy, aimed at water leakages reduction avoiding very expensive pipe replacement programs. On the contrary, few experimental data are available in literature, with regard to PRV transient behavior in terms of its response to incoming pressure waves, as well as the time required for achieving the pressure set point. In this paper, the results of some experimental tests are presented. The PRV is installed in a single high density polyethylene pipe and transients are generated by operating the downstream end valve. Two types of tests are considered: a partial valve closure and opening simulating a water demand decrease and increase, respectively. The analysis of the experimental pressure traces points out the valuable effects of the PRV on transient characteristics with respect to the case of a partially closed in-line valve with a constant opening degree

The Skeletonization of Milan WDS on Transients Due to Pumping Switching off: Preliminary Results

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Functioning conditions of the Casale pumping station in Mantova, Italy

Abstract. Pump speed, input power, pressure and discharge data are analyzed for evaluating functioning conditions of Casale pumping station in Mantova, Italy, managed by TeaAcque. A model based on the affinity laws is used to simulate the behavior of the installed variable speed pumps. Quadratic and cubic polynomial curves are used to fit the pump data given by the affinity laws. Such curves allow predicting the efficiency when the functioning conditions change. The relationship between the rotation speed and the efficiency is also derived