Francesco Pugliese

Performance of vertical-axis pumps as turbines

ABSTRACT Hydropower generation in water distribution networks (WDNs) is an attractive topic in the field of management of water systems. Pumps as turbines (PATs) allow coupling pressure control with power generation. Although PATs have several advantages over traditional turbines, theoretical and experimental studies are still required to overcome the reduced knowledge about their performances, especially for vertical-axis pumps. To this end, laboratory experiments on three vertical pumps running in reverse, with different number of stages and motor efficiency classes, were carried out and discussed. Results were compared with theoretical models available in the literature for horizontal PATs, with maximum errors around 20% and 30% for head and power curve, respectively. Analytical relationships for vertical PATs were proposed for better agreement. The dependence of performances by the number of stages and the motor efficiency class was also discussed.

The relationship between Flocking Behavior and the Emergence of Leadership

This paper examines the relationship between flocking behaviour and leadership. In order to achieve this aim, we simulate two co-evolving populations of robots: predators and prey. Behavioural and quantitative analysis indicate that a wellstructured hierarchic leadership emerges in the population of predators after the evolution. The emergence of leadership relates to high levels of fitness, so leadership seems to be a winning strategy. We show that the leader role has been assumed by more explorative individuals. Moreover, exploratory behaviours mostly appear when there is a low following behaviour. Therefore, exploratory and following capabilities seem to be complementary both within every replication and within simulations with different perceptual conditions. On the other hand, leadership seems to be a strategy to enable followers to be more explorative. Index Terms: Leadership, Evolutionary Robotics, Flocking

Optimal Design of LIDs in Urban Stormwater Systems Using a Harmony-Search Decision Support System

During the last years, climate changes and urbanization are causing huge urban pluvial flood events in many countries in the world, driving to both develop and apply effective and innovative approaches for the design and management of urban stormwater systems. The gradual urbanization is provoking the increase of impervious surfaces and, consequently, of surface runoff and velocity and the reduction of concentration times of watersheds, both increasing soil erosion and worsening the water quality as a consequence of the intensive contamination. In this field, Low Impact Development (LID) practices for urban runoff control can be intended as an effective approach to both improve the urban resilience against the flooding risk and assure environmental interventions to adequate the urban stormwater systems to both climate and land use changes. In this paper, a Decision Support System (DSS) for the optimal design of LIDs in urban watershed is presented and discussed. The procedure is tested on Fuorigrotta (IT) and Ponticelli (IT) urban watersheds, with the aim of assessing the effectiveness of LIDs application in reducing both the flooded and conveyed volumes, at the expense of cost-effective solutions.

Preliminary Development of a Method for Impact Erosion Prediction in Pumps Running as Turbines

In this paper preliminary results of the numerical assessment of PAT erosion, caused by the impingement of solid particles in the water flow, are provided and discussed. A CFD model was developed by the Universita degli Studi di Napoli Federico II to investigate the fluid dynamics of a PAT and coupled with the in-house E-CODE developed by the Politecnico di Milano for wear estimation. The erosion simulations were performed to assess the wear of PAT components, namely inlet, impeller, volute and outlet pipe, for abrasive particles with different size, aiming at estimating the relation between the fluid dynamics of the slurry flow and the development of the erosion process.

Development of Categorisation Abilities in Evolving Embodied Agents: A Study of Internal Representations with External Social Inputs

This paper investigates the behaviour of embodied and situated agents, which perform tasks requiring categorisation skills. These agents are simulated robots selected by an artificial adaptation process. Their task is to categorise objects with different shapes. To achieve this goal, the robots can use sensory information from the environment and external “linguistic” inputs. The results show that the agents are able to solve the categorisation task by conveniently integrating the experienced sensory-motor states and linguistic inputs. The aim of this work is to demonstrate that autonomous agents are able to develop some high-level cognitive abilities. Interestingly, the behavioural pattern seems to be in agreement with the theoretical hypothesis “social” information (external inputs) facilitates individual capacity to categorise, by producing good internal representations.