955 research outputs found
Le infrastrutture verdi in ambito urbano: i casi di San Sebastiano al Vesuvio e di San Cipriano Picentino
No full textOggetto di questo articolo è l’utilizzo del sistema Gis nella costruzione di itinerari di connessione territoriale in ambito naturalistico. Gli itinerari, intesi come infrastrutture verdi, svolgono quattro ruoli principali: proteggere lo stato dell'ecosistema e la biodiversità, migliorare il funzionamento degli ecosistemi e promuovere i servizi ecosistemici, promuovere il benessere e la salute della società e sostenere lo sviluppo di un'economia verde e una gestione sostenibile del territorio e delle acque.
Nella seconda parte dell’articolo vengono descritti i casi analizzati del comune di San Sebastiano al Vesuvio (Na), inserito nello straordinario ambito geologico-paesaggistico del Vesuvio, il landmark paesaggistico più riconosciuto della nostra regione e San Cipriano Picentino (Sa), inserito nell’altrettanto straordinario territorio dei Monti Picentini
Experimental Assessment of Gas Static Meters under Different Operating Conditions
No full textThis paper compares the metrological performance of a sample of commercial domestic/residential smart meters for natural gas (G4). In particular, the performance degradation of electronic static and dynamic gas meters has been evaluated. The sample was composed by ultrasonic gas meters, thermal mass meters and diaphragm gas meters. The tests, performed on the gas meters, reproduce the most severe operating conditions (i.e. filed test) such as the influence of the gas composition, the temperature difference between gas and meter, the gas humidity and the presence of dust in the gas. Furthermore, the meters have been undergo to some endurance tests such as start and stop and to the high flowrate runs
A simplified methodology to simulate a heat exchanger in an aircraft’s oil cooler by means of a Porous Media mode
No full textThis work describes a simplified methodology to model (air-side) a heat exchanger within a computational fluid dynamics analysis of an oil cooler device for aerospace applications. Although several CFD solvers provide specific tools to simulate a heat exchanger, sometimes the available data, as for example, cooling plate geometries, dimensions and their arrangement in the heat exchanger, are not exhaustive enough to set up the numerical simulation. Hence, in the present research was used a porous media model to simulate the main effects of the heat exchanger, such as pressure drop and heat rejection, on the flowfield occurs place inside an aircraft oil cooler system. In this way, the need to model the real complex geometry of the heat exchanger is avoided. In this framework, present analyses aim at verifying that the heat exchanger, under investigation, is able to satisfy the system requirements in terms of heat rejection of the engine's oil cooling system, foreseen for the aircraft operating conditions. In particular, the paper analyzes a turboprop oil cooler heat exchanger when the aircraft is flying at cruise conditions, namely 2743 m (9000 ft) altitude, focusing attention on several heat exchanger flow field features such as air pressure drop, temperature change and mass flow rate. Finally, those numerical results are analyzed in detail and compared to experimental data available for the heat exchanger, thus pointing out that this design approach represents a viable option in the framework of oil cooling heat exchanger performance investigation. © 2015 Published by Elsevier Ltd
Prefazione
No full textIl XV convegno del CIRSIL, ospitato dall’Università degli Studi di Napoli Federico II, in continuità con il XIV convegno del CIRSIL (Pisa, settembre 2021) dedicato ai complessi rapporti tra didattica delle lingue e ideologie dominanti nell’età moderna e contemporanea, ha posto al centro del dibattito il riconoscimento della intrinseca politicità della realtà linguistica, esplorando come tale riflessione abbia accompagnato nel tempo la costruzione del metodo e la prassi della ricerc
Numerical study of the optimization of the pitch angle of an alternative jet fan in a longitudinal tunnel ventilation system
No full textThis paper presents the results of a numerical investigation carried out on an alternative jet fan, noted in literature like Banana Jet Fan, equipped with inlet/outlet silencers inclined at a fixed pitch angle (a)
inclined toward the tunnel floor. The aim of this paper is to optimize the pitch angle comparing the different ventilation performances,
in terms of reduction of pressure losses and of energy saving, without vehicles and with traffic jam. The average velocity profile variation of the tunnel air jet around the outlet jet fan zone was evaluated
with the numerical CFD analysis. This analysis showed that there exists an optimal pitch angle which minimizes the pressure losses, due to the flow attachment by varying the operative conditions (free tunnel and traffic jam)
Fluid dynamic performances of traditional and alternative jet fans in tunnel longitudinal ventilation systems
No full textThis paper presents the results of a numerical investigation carried out on an alternative jet fan, known in literature like Banana Jet, and it compares its fluid dynamic performances to traditional axial ventilation systems. The alternative jet fan is equipped with inlet/outlet sections inclined at a fixed pitch angle (a) toward the tunnel floor. This approach establishes an alternative solution that is able to provide a safety level equivalent to the traditional solution, in different scenarios. Both systems are installed in an oneway
tunnel and two different scenarios (without vehicles and with traffic jam) are considered, in event of fire. The fire was simulated setting heat flux on Heavy Good Vehicle (HGV) surface and comprehensive
of radiative heat flux. Computational Fluid-Dynamic (CFD) are applied to simulate the ventilation in the unidirectional tunnel through k–e model, including temperature fields. The results show, for both scenarios, the existence of an optimal pitch angle which offers advantages in comparison with the traditional system (a = 0) in terms of plant and running costs. In the next paper, the influence of the radiative heat flux for the optimal pitch angle will be explicitly considered
High heat fluxes measurement in hypersonic wind tunnel tests: comparison among different sensors
No full textThe measurement of heat fluxes is one of the key measurement techniques in high enthalpy facilities, since heat fluxes are
important quantities for judging the quality of a thermal protection system. Furthermore, heat flux measurements are widely used
for flow characterization. The hypersonic plasma wind tunnel Scirocco, at Italian Center for Aerospace Research (CIRA) in
Capua (Italy), is a giant facility and can be considered the largest and most powerful in the world in its category. It is
characterized by a maximum Mach number equal to 13, and then by high heat fluxes impacting on the test sample. Recently, a
probe for stagnation point heat flux measurements, based on a “slug sensor” has been designed and realized. Such a sensor offers
great advantages compared with traditional alternatives (Gardon gauge) such as low cost and prolonged durability. The present
paper deals with the design, realization and test of this sensor for a test in the Scirocco plasma wind tunnel.The gardon-gauge is
compared with the HFM, slugs and calorimeter type sensors, opportunely designed and the advantages and disadvantages of the
employed sensors are highlighted
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