Search results for "fluid"
showing 10 items of 5513 documents
Simulation Study on the Use of Argon Mixtures in the Pressurized Motored Engine for Friction Determination
2020
Mechanical friction and heat transfer in internal combustion engines are two highly researched topics, due to their importance on the mechanical and thermal efficiencies of the engine. Despite the research efforts that were done throughout the years on both these subjects, engine modeling is still somewhat limited by the use of sub-models which do not fully represent the phenomena happening in the engine. Developing new models require experimental data which is accurate, repeatable and which covers wide range of operation. In SAE 2018-01-0121, the conventional pressurized motored method was investigated and compared with other friction determination methods. The pressurized motored method p…
Further Experimental Investigation of Motored Engine Friction Using Shunt Pipe Method
2019
Mechanical friction is a significant power dissipater in the internal combustion engine. In the effort of designing more efficient and less pollutant engines, friction reduction is certainly on the agenda to be investigated. Such investigation cannot be possible without an accurate measurement of the same quantity. This publication regards a continued study on the mechanical friction determination in an internal combustion engine using the Pressurised Motoring Method. In this work, the friction mean effective pressure of a four-cylinder compression ignition engine was investigated with varying engine speed and manifold pressurisation, using a dedicated high precision sensor for the correct …
EXTENDED VALIDATION OF DYNAMIC IRREVERSIBLE THERMOPORATION: A NOVEL THERMAL PROCESS FOR MICROBIAL INACTIVATION
2017
A novel thermal treatment for microorganism inactivation, characterized by a very rapid temperature increase (up to 30C/s) and a low final temperature (up to 65C) maintained for a relatively short holding time, has been recently presented and tested by the authors, showing microbial load reduction greater than 5 log units against several common bacteria and yeasts. With the aim of extending the possible use of the new thermal treatment to a wider microorganisms class, in this work the dynamic irreversible thermoporation (DIT) treatment was further tested on a well-known thermoresistant strain, the Enterococcus hirae: The results of these new experimental tests confirmed the reliability of t…
Knock Resistance Increase through the Addition of Natural Gas or LPG to Gasoline: An Experimental Study
2013
Bi-fuel spark ignition engines, nowadays widely spread, are usually equipped with two independent injection systems, in order run the engine either with gasoline or with gaseous fuel, which can be Natural Gas (NG) or Liquefied Petroleum Gas (LPG). These gases, besides lower cost and environmental impact, are also characterized by a higher knock resistance with respect to gasoline that allows to adopt a stoichiometric proportion with air also at full load. Gasoline, on the other hand, being injected as liquid, maintains higher volumetric efficiency and hence higher power output. As a compromise solution, it could be desired to exploit the advantages of both gasoline and gas (NG or LPG), thus…
PROGETTAZIONE E VERIFICA SPERIMENTALE DI UNA MICROTURBINA IDRAULICA PER L’INDUSTRIA ALIMENTARE
2014
In questo articolo sono descritte le attività di ricerca e sviluppo di una micro-turbina idraulica inserita all’interno di un macchinario che opera un nuovo processo di abbattimento della carica batterica applicabile nell’industria dell’imbottigliamento delle bevande. Peculiarità della turbina progettata è la geometria della palettatura della girante, dritta ed a sviluppo puramente assiale, che ne rende estremamente economica la realizzazione. Lo scambio di energia avviene grazie al moto vorticoso impresso al fluido (swirl) mediante opportuno posizionamento dei condotti di adduzione. Lo studio della turbina è stato condotto mediante classico approccio unidimensionale, mentre il dimensioname…
Realistic Steady State Performance of an Electric Turbo-Compound Engine for Hybrid Propulsion System
2022
The efficiency of Hybrid Electric Vehicles (HEVs) may be substantially increased if the unexpanded exhaust gas energy is efficiently recovered and employed for vehicle propulsion. This can be accomplished employing a properly designed exhaust gas turbine connected to a suitable generator whose output electric energy is stored in the vehicle storage system; a new hybrid propulsion system is hence delineated, where the power delivered by the main engine is combined to the power produced by the exhaust gas turbogenerator: previous studies, carried out under some simplifying assumptions, showed potential vehicle efficiency increments up to 15% with respect to a traditional turbocharged engine. …
Modello dinamico di iniettore di gas per motore ad accensione comandata
2010
Nel presente lavoro si studia la complessa dinamica dell’otturatore di un iniettore di gas a solenoide per motori ad accensione comandata; come è noto, esso è sottoposto a spinte di diversa natura ed il suo moto ha un influenza determinante nei confronti della massa di combustibile erogata, la quale viene di norma modulata intervenendo sulla durata dell’intervallo di eccitazione del solenoide, chiamato “tempo di iniezione”. Ad otturatore completamente aperto, la massa di gas che attraversa la sezione di uscita dell’iniettore dipende esclusivamente dalle condizioni del fluido a monte dell’iniettore e dalla durata del tempo di iniezione: ciò rende lineare la caratteristica di funzionamento de…
The Rotary Aero-Engine from 1908 to 1918
2012
The rotary aero engine is a special type of air-cooled radial engine, where the cylinders are arranged like the spokes of a wheel and turn around the crankshaft. The propeller is connected to the cylinders, while the crankshaft is fixed to the frame. The rotary aero engine, developed in 1908, set new standards of power and light weight within the aircraft industry. It was adopted by many pioneer aviators and widely used to set records of endurance, speed and height. Many aero engine manufacturers produced different models and variants of this type of engine, which was extensively used until the end of the First World War. The latest evolution of the rotary engine was the counter-rotary arra…