Gianluca Pasini

Numerical Comparison of an Electric Turbo Compound Applied to a SI and a CI Engine

In a medium term scenario Internal Combustion Engine (ICE) downsizing and hybrid powertrain will represent the actual trend in vehicle technology to reduce fuel consumption and CO2 emission. Concerning downsizing concept, to maintain a reasonable power level in small engines, the application of turbocharging is mandatory both for spark ignition (SI) and compression ignition (CI) engines. Following this aspect, the possibility to couple an electric machine to the turbocharger (electric turbo compound, ETC) to recover the residual energy of the exhaust gases is becoming more and more attractive, as demonstrated by several studies around the world and by the current application in the F1 Championship.The present paper shows the first numerical results of a research program focused on the comparison of the benefits resulting from the application of an ETC to a small twin-cylinder SI engine (900 cm3) and to a four cylinders CI engine (1600 cm3), both of the same maximum power. Starting from the experimental maps of several turbines and compressors, complete model of both turbocharged engines were created using the AVL BOOST one-dimension code.Concerning the SI engine, first numerical results show that ETC can improve the average overall efficiency at the highest engine speeds and loads. Besides, boost range extension in the lowest engine rotational speed region and a possible reduction of turbo lag represent other benefits related to ETC application.On the other hand, the adoption of an ETC to a CI engine shows larger benefits in term energy recovery at the highest engine speeds, with consequent reduction of fuel consumption, mainly due to the absence of throttling effects in the intake manifold and related pumping losses.Copyright

Auxiliary Power Units for pleasure boats

Due to the growing interest shown worldwide in reducing pollution in all transportation fields, and also in order to improve comfort by avoiding acoustic emissions inside sea ports or protected areas, shipyards have recently started to develop auxiliary power units fed by hydrogen, for feeding electrical loads on pleasure boats. Different solutions can be considered, with hydrogen stored on-board or, much more interesting, produced on request. This paper analyzes some of these options, by presenting a reforming process starting from liquefied natural gas (LNG) which is more and more considered also as fuel for the main propulsion power unit ones. An experimental laboratory activity was also performed, aimed to test some of the components of the auxiliary power unit, i.e. the fuel-cell system, and their interface with the electrical system on-board.

The ἐξεταστιχὸν εἶδος of theRh. Al. and Parallels in Aeschines'Against Timarchusand Demosthenes'On the False Embassy

L9 exetastikon eidos della Rh. Al . (capp. 5 e 37) appare come una tipologia argomentativa utilizzabile in contesti istituzionali e non, ovvero nei discorsi privati e nei discorsi pubblici. In questi ultimi, in particolare, esso tende a fondersi con il kategorikon eidos , quantunque non vada statutariamente sussunto nel genere giudiziario. Cio e ben evidente nella Contro Timarco di Eschine e nell9 orazione Sull9ambasceria corrotta di Demostene.