Hybrid Storage System Control Strategy for All-Electric Powered Ships

Abstract In marine applications all-electric propulsion systems are employed on surface ships that are subjected to particular constraints, generally due to environmental restrictions. The technological advancement of electrochemical batteries, which are today characterized by higher capacity and efficiency, has widened their fields of application, although these storage systems require an accurate design to limit their initial and maintenance costs. In order to reduce battery charge and discharge peak currents, supercapacitor modules are generally adopted with the aim to extend batteries expected life. The proper management of energy fluxes within the hybrid architecture, and in particular among batteries, capacitors and loads requires a specific control, called EMS – Energy Management Strategy. In this paper, a novel EMS, based on constrained minimization problem, is proposed and verified with reference to a case study of a waterbus operating in restricted waterways on different routes. The procedure is based on a preliminary solution of an off-line optimization with respect to a known mission profile. Hence, a real-time control strategy is properly evaluated, in order to guarantee robustness against the unavoidable uncertainties, which occur during the operating conditions. In the last part of the paper, a numerical application is presented with the purpose to emphasize the feasibility of the proposal

a numerical procedure for evaluating physical parameters of ergonomic assessment for cart pushing pulling tasks

Abstract Manual Material Handling (MMH), by pushing or pulling carts, is a common task that characterizes any manufacturing or service operation, and there is always a significant human input to those operations in terms of physical load. The physical load represents the effect of input forces during MMH operations that depend on the interaction between material handling equipment and the working environment. Many times MMH represents a critical issue related to human-machine interaction due to the carts can work in environment with parameters different from those used in designing, subjecting workers to risk of musculoskeletal disorders. The aim of this work, developed in collaboration with Fiat Chrysler Automobiles (FCA), is to develop a new procedure that allows estimating the initial and the maintenance forces necessary to push or pull carts, knowing the characteristics of the cart and the environment in which it works, in order to preventively assess the ergonomic indexes according to ISO 11228-2. The procedure is based on multibody simulations. The cart is modeled by Computer Aided Design (CAD) code and, then, imported in a multibody code where numerical simulations are performed in order to calculate the forces. In the multibody code static and dynamic friction coefficients of bearing of wheels are assigned, together with parameters of contact between wheels and floor. Changing the pivot angle of two floating wheels, several simulations have been carried out. Moreover, considering a cart used at the assembly line of the FCA plant of Pomigliano d'Arco (Naples), experimental tests have been performed in order to validate the procedure by comparing numerical results with the experimental ones

La responsabilità professionale del medico competente: aspetti normativi, giuridici e medico legali

Anche la figura del medico competente ha visto profonde modifiche nell\u2019assetto del giudizio sulla sua responsabilit\ue0 professionale in virt\uf9 delle nuove impostazioni normative. Vengono analizzati gli aspetti medico legali inerenti le possibili criticit\ue0 nei confronti del lavoratore e del datore di lavoro con particolare riferimento alle linee guida nello specifico ambito operativo

Air Pollution and Air Quality State in an Italian National Interest Priority Site. Part 2: The Pollutant Dispersion

Abstract In Campania region, southern Italy, a National Interest Priority Sites (NIPS) was identified: "Litorale Domitio-Agro Aversano" NIPS L.426/98, that includes a large part of the polluted agricultural land, belonging to more than 61 municipalities in the Naples and Caserta provinces. This second paper represents an analysis developed for a LIFE project (LIFE11/ENV/IT/275–ECOREMED): "Implementation of Eco-Compatible Protocols for Agricultural Soil Remediation in Litorale Domizio-Agro Aversano NIPS". The contribution of this second paper to the above-mentioned LIFE project consists in the appraisal of the air quality state in this NIPS area, estimating the pollutant concentrations of the main air pollutants (CO, VOC, NO X and PM 10 ) in the area under investigation due to the principal industrial systems (namely punctual sources) and to the main diffused sources. All entropic activities which determine emissions in the atmosphere, in fact, depending on the distance from the areas under examination, could contribute to the soil qualification. The assessment of the air quality to local scale was carried by integrating the data of emission inventory in the NIPS area, that was estimated and reported in the first paper (Part 1), with elaborations of a Gaussian dispersion model

Domain modeling and grid generation for multi-block structured grids with application to aerodynamic and hydrodynamic configurations

About five years ago, a joint development was started of a flow simulation system for engine-airframe integration studies on propeller as well as jet aircraft. The initial system was based on the Euler equations and made operational for industrial aerodynamic design work. The system consists of three major components: a domain modeller, for the graphical interactive subdivision of flow domains into an unstructured collection of blocks; a grid generator, for the graphical interactive computation of structured grids in blocks; and a flow solver, for the computation of flows on multi-block grids. The industrial partners of the collaboration and NLR have demonstrated that the domain modeller, grid generator and flow solver can be applied to simulate Euler flows around complete aircraft, including propulsion system simulation. Extension to Navier-Stokes flows is in progress. Delft Hydraulics has shown that both the domain modeller and grid generator can also be applied successfully for hydrodynamic configurations. An overview is given about the main aspects of both domain modelling and grid generation

Acoustic analysis of an exhaust manifold by Indirect Boundary Element Method

The present work is aimed at the development of a numerical procedure, based on the usage of the Boundary Element Method (BEM) as implemented in the software LMS Virtual.Lab, for the vibro-acoustics analysis of an exhaust manifold. The manifold vibrations are induced by two different ways: engine vibrations (transmitted to the manifold surfaces) and turbulences generated by the air flow in the exhaust system. The indirect BEM (IBEM), with a variational solution algorithm, is adopted to assess the exhaust manifold acoustic radiation. The modal analysis of the acoustic cavity is realized by the Finite Element Method (FEM) and the corresponding eigenfrequencies compared with those obtained by an IBEM forced response analysis and by experimental measurement. Experimental acoustic pressures at the manifold inlet and outlet are measured in anechoic room in order to compare with corresponding numerical predictions and assess the accuracy level obtained