Higher Institute on Territorial Systems for Innovation
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Overview of the JET results in support to ITER
No full textThe 2014 - 2016 JET results are reviewed in the light of their significance for optimising the ITER research plan for the active and non-active operation. More than 60 h of plasma operation with ITER first wall materials successfully took place since its installation in 2011. New multi-machine scaling of the type I-ELM divertor energy flux density to ITER is supported by first principle modelling. ITER relevant disruption experiments and first principle modelling are reported with a set of three disruption mitigation valves mimicking the ITER setup. Insights of the L - H power threshold in Deuterium and Hydrogen are given, stressing the importance of the magnetic configurations and the recent measurements of fine-scale structures in the edge radial electric. Dimensionless scans of the core and pedestal confinement provide new information to elucidate the importance of the first wall material on the fusion performance. H-mode plasmas at ITER triangularity ( H = 1 at β N ~ 1.8 and n / n GW ~ 0.6) have been sustained at 2 MA during 5 s. The ITER neutronics codes have been validated on high performance experiments. Prospects for the coming D - T campaign and 14 MeV neutron calibration strategy are reviewed
Technologies for CO2 Reductions in ICEs
No full textNowadays the fast development of the internal combustion engine technologies together with the day by day more stringent issues raised by the environmental concerns, there is a strong demand for an improvement in combustion efficiency as well as in terms of pollutant emissions to the environment. Alternative fuels such as natural gas has been taken into account and applied on the commercial vehicles. Natural gas is primarily composed of methane and has several alternative features such as a high number of hydrogen to carbon ratio and high research octane number, which means it is possible to give higher boost to the fuel air mixture with less risk to have knock phenomenon. On the other hand, variable valve actuation (VVA) has been proved to be an effective way to increase engine efficiency by decreasing pumping losses at partial load conditions. In this context, research work has been proceed with CORE (CO2 reduction for long distance transport) project, which is a collaborative large-scale integrating project for a call within FP7-SUSTAINABLE SURFACE TRANSPORT of the EC. The project consortium consists of three truck manufactures in Europe: Volvo, Daimler and IVECO, together with 13 other partners in the automotive industry and universities and it aims to demonstrate a substantial reduction of CO2 emissions, 15\% improved fuel efficiency compared to a EURO V engine and fulfilling EURO VI emission legislation at the same time. The project is inserted in a series of research projects, which have been performed by the EC with the aim of boosting the cooperation among car manufactures, suppliers and technical universities as well as of defining enhanced and feasible solutions for the market. During this thesis research work within the CORE Project, a heavy duty engine fuelled with compressed natural gas (CNG) using VVA technology has been numerically modelled using 0/1D commercial tool GT Power. Since with VVA technology, it results lower exhaust temperatures which is not favoured by considering the aftertreatment working conditions. The advanced combustion management, thus the retarding combustion strategy combined with different valve profiles, has been numerically simulated in order to reach a good condition for aftertreatment working conditions both at steady state and transient conditions. Retarding combustion strategies have been numerically tested in order to increase the turbine outlet temperature by limiting the fuel consumption increment. At the same time, the upper limit of the turbine inlet temperature has also been taken into account. In order to obtain more opportunities to increase the model accuracy and to extend its applicability, based on the engine model built with GT Power, a user defined combustion based on fractal approach has been embedded. This user defined combustion is composed of several submodels (flow submodel, CAD submodel, flame submodel, combustion submodel...etc). The validation of these submodels' coupling is done by comparing simulated and experimental data over a complete engine operating map after the calibration work. The model has shown its ability to reproduce the experimental data under the same working conditions with very high accuracy. Thus with this embedded combustion approach, it makes the model from a non-predictive one to a predictive one. Several applications have been numerically proceeded with this new model under transient condition tests with advanced combustion management and it demonstrates its good applicability and accuracy. Then this newly developed user combustion approach has been applied on the other two light duty engines: 1.4l T-jet PFI natural gas engine and 1.4l T DI natural gas engine. The engine models built in GT power have been carefully calibrated and they are able to reproduce the experimental data under the same working conditions with very high accuracy. A new application has been tested based on the engine models in which it is able to produce a spark advance value by targeting a proper MFB50 value. The models are able to give comparable spark advance results once the users target the experimental MFB50 values. This again further proves the robustness of the predictive model the developed user combustion approach. Meanwhile doing the predictive modelling for both engines, the flow submodel of the user combustion approach has also been improved with a available set of flow data obtained from 3D CFD simulations.The simulated turbulence intensity over the engine revolution has reached a comparable level of the results coming from 3D CFD data. The outcome of the work during the Ph.D study has been published in the following list. 1. Mirko Baratta, Roberto Finesso, Daniela Misul, Ezio Spessa, Yifei Tong, and Cesare Peletto. Potential of the variable valve actuation (VVA) strategy on a heavy duty cng engine. In ASME 2014 12th Biennial Conference on Engineering Systems Design and Analysis, American Society of Mechanical Engineers, 2014. 2. Mirko Baratta, Roberto Finesso, Daniela Misul, Ezio Spessa, Yifei Tong, and Cesare Peletto. Optimization of a user-defined fractal combustion model and its application to the assessment of the behavior of a heavy-duty NG engine equipped with VVA under steady-state and transient conditions. Int J of Mech and Control vol. 18 no.1 (2017
Sustainable urban heat strategies: Perspectives from integrated district energy choices and energy conservation in buildings. Case studies in Torino and Stockholm
No full textHeat demand in buildings is responsible for a large portion of energy loads in Europe, and building renovations represent an important opportunity to achieve sustainability objectives. Efficient district heat (DH) can represent a cost-effective heat source for buildings. Yet, building heat demand reductions will have implications on sustainable DH production and operation. Analysis is therefore needed to identify cost-effective strategies for low-carbon heat solutions in integrated energy systems. This paper proposes a methodology to investigate different scenarios to 2050 involving integrated heat supply and building envelope investment choices in Torino, Italy and Stockholm, Sweden. The goal is to provide an overview of opportunities for decision makers in elaborating heat strategies including DH. Results show that opportunities exist to achieve consistent energy savings and emissions reduction through strategic combination of DH and building renovation investments. A systems approach is essential to avoid unnecessary investments or early retirement of assets: building renovations should be planned carefully as lower DH base loads could lead to increased running costs, and DH investments need to be adapted to long-term building improvements. Reduced peak loads can allow increased use of low-grade heat, higher merit-order power generation and in some instances cost-effective expansion of DH
System-level architecture for mixed criticality applications on MPSoC: A space application
No full textGearshift control for hybrid powertrains with AMTs
No full textThis paper describes a control algorithm for gearshifts maneuvers designed for a hybrid electric vehicle architecture in which an electric machine is connected to the output of a traditional five-speed automated manual transmission, thus obtaining a torque-fill capability during gearshifts. The controller is realized dividing the entire gearshift process into five phases. The objectives of each phase, the equations for computing the controller output signals and the conditions that determine the passage from one phase to the next are reported. A nonlinear dynamic model of the powertrain is described and used to verify through simulation the effectiveness of the controller. The results obtained by applying the proposed algorithm are promising in terms of vehicle dynamic performances
The impact of servitization on Italian manufacturing companies
No full textServitization can be defined as the process of innovating company's capabilities and processes to support the shift from selling product to selling Product-Service Systems (PSS), i.e. integrated offerings of products and services. This process of manufacturing companies has been recognised to provide many advantages, including increasing the value of the offerings, developing customers' loyalty, generating profits throughout the whole product life cycle, etc. Despite the many studies related to this process and its effects, there is a major lack concerning its quantification. This paper aims at filling this lack through an in-depth analysis of medium-large size Italian companies in the manufacturing sector. In detail, this study offers (i) an analysis of servitization process extent in terms of percentage of servitized companies (ii) a taxonomy of the services offered and (iii) an estimation of their relative diffusion. Also, the paper discusses a perspective on the effects that this process may have on production technologies and system
Increased micronucleus frequency in peripheral blood lymphocytes predicts the risk of bladder cancer
No full textOne-dimensional Advanced Beam Models for Marine Structural Applications
No full textAt preliminary design stage, the global mechanical behavior of large marine vessels such as container ships has previously been analyzed idealizing them as a classical beam. These structures are complex and a classical beam idealization significantly compromises important structural behavior associated with cross section warping or in-plane displacements. On the other hand, 3D Finite Element (FE) models have been utilized which are accurate in capturing these details but pose high computational cost. In present work, structural analyses of marine vessels with realistic boundary conditions have been presented using well-known Carrera Unified Formulation (CUF). Using CUF, higher order theories can be implemented without the need of ad-hoc formulations. The finite element arrays are written in terms of fundamental nuclei for 1D beam elements that are independent of problem characteristics and the approximation order. Thus, refined models can be developed in an automatic manner. In the present work, the beam cross sections are discretized using elements with Lagrange polynomials and the FE model is regarded as Component-Wise (CW), allowing one to model complex 3D features, such as inclined hull walls, floors and girders in the form of components. The work is mainly divided in two parts: Hull in vacuo (in absence of water) and Hull with Hydrostatic Stiffness (in presence of water). The former involves static and dynamic structural analyses of hulls with realistic geometries without the effect of water. The later involves static and dynamic analyses of realistic hull geometries that are supported by buoyancy springs. The stiffness of buoyancy springs is made part of the fundamental nuclei and the corresponding FEM matrices for hydrostatic and hydrodynamic loads are obtained. The hydrodynamic loads have been considered in the form of Radiation Wave loads which include damping and added mass effects. Utilization of Component-Wise (CW) model under hydrodynamic loads has afforded an ease in modelling the complex geometrical configurations such as realistic boat shapes and the dynamic response analyses of aircraft carrier due to moving aircraft. All the analyses have been validated with published literature and their computational efficacy is established through their comparison with the results from commercial code
Application of Structural Topology Optimization to Couple Thin-Walled Stiffened Box-Beams
No full textFuture generations of civil aircrafts and unconventional unmanned configurations demand for innovative structural concepts to improve the structural performance, and thus reduce the structural weight, but also to allow possible material couplings to be made. Static and dynamic aeroelastic stability can be altered by these couplings. It is therefore necessary to use an accurate and computationally efficient beam model during the preliminary design phase. A stiffened box, made of isotropic material, but with the stiffeners oriented so that they originate the expected bending/torsion coupling, is considered in the present work. The overall equivalent bending, torsional and coupled stiffness is derived by means of homogenization of the shell skin and of the stiffener plate stiffness. A new equivalent homogeneous orthotropic material is determined and introduced into the equivalent plate configuration. The accuracy of the simplified beam model is demonstrated by the application of structural topology optimization technique by means of Altair Optistruct. Good agreement has been found between the theoretical simplified beam model and numerical analysis