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2015-09-06
Technical Paper
2015-24-2390
Shashi Aithal, Stefan Wild
Design and optimization of automotive engines present unique challenges on account of the large design space and conflicting constraints. Optimizing the fuel consumption and reducing emissions over a driving cycle is a good example. Inlet pressure, equivalence ratio, humidity, EGR fraction, inlet air temperature, ignition timing, engine load, engine speed (RPM) etc. each impact fuel consumption and emissions and thus represent a vast parametric space to conduct de sign and global optimization studies. This large parametric space is further increased when one has to consider newer fuels and fuel-blends (varying ratios of fuel-additive mixtures) further complicating the design-optimization problem. The large design parameter space precludes the use of detailed numerical or experimental investigations. Physics-based reduced-order models (quasi-dimensional models) can be used effectively in the design and global optimization of such problems.
2015-09-06
Technical Paper
2015-24-2468
Kar Mun Pang, Hiew Mun Poon, Hoon Kiat Ng, Suyin Gan, Jesper Schramm
This work concerns the modelling of soot formation process during n-dodecane and diesel spray combustion under engine-like conditions. The key aim is to investigate the effects of chemical kinetics on soot formation characteristics at different ambient temperatures. Numerical computation is performed using an open-source computational fluid dynamics software. Prior to simulating the diesel combustion, numerical models including a revised multi-step soot model is validated by comparing the experimental data of n-dodecane fuel in which the associated chemistry is better understood. In the diesel spray simulations, a single component n-heptane model and the multi-component Diesel Oil Surrogate (DOS) model which uses a reduced toluene sub-mechanism to represent the aromatic compound are adopted. The third mechanism used comprises skeletal chemical mechanisms of n-hexadecane and heptamethylnonane.
2015-09-06
Technical Paper
2015-24-2400
Andrea Matrisciano, Anders Borg, Cathleen Perlman, Harry Lehtiniemi, Michal Pasternak, Fabian Mauss
In this work we present a soot source term tabulation strategy for soot predictions under Diesel engine conditions within the zero-dimensional Direct Injection Stochastic Reactor Model (DI-SRM) framework. The DI-SRM accounts for detailed chemistry, in-homogeneities in the combustion chamber and turbulence-chemistry interactions. The previously developed method [1] was extended with a framework facilitating the use of tabulated soot source terms. The implementation allows for using soot source terms provided by an online chemistry calculation, and for the use of a pre-calculated flamelet soot source term library. Diesel engine calculations were performed using the same detailed kinetic soot model in both configurations. The chemical mechanism for n-heptane used in this work is taken from Zeuch et al. [2] and consists of 121 species and 973 reactions including PAH and thermal NO chemistry. The engine case presented in [1] is used also for this work.
2015-09-06
Technical Paper
2015-24-2506
Paolo Iodice, Adolfo Senatore
Nowadays, due to catalyst improvements and electronic mixture control of last generation vehicles equipped with internal combustion engine, the most significant part of the total emissions of carbon monoxide and unburned hydrocarbons takes place during the cold phase, if compared with those exhausted in hot conditions, with a clear consequence on air quality of urban contexts. The purpose of this research, developed by the Department of Industrial Engineering of the University of Naples Federico II with reference to an European background, is a deeper analysis of the engine and after-treatment system behaviour within the cold start transient and the evaluation of cold start additional emissions: a methodology was developed and optimized to evaluate the cold transient duration, the emitted quantities during the cold phase and the relevant time-dependence function.
2015-09-06
Technical Paper
2015-24-2511
Theodoros Grigoratos, Georgios Fontaras, Giorgio Martini, Cesare Pelleto
Gas operated Heavy Duty Vehicles (HDV) powered by Natural Gas (NG) are seen as a possible option for curbing CO2 emissions, fuel consumption and operating costs of goods transport. Initiatives have been adopted by various organizations worldwide in order to introduce NG fueled HDVs in their fleets. In this study, an advanced newly designed CNG prototype engine, which was developed in the framework of the FP7 research project “CO2 Reduction for long distance transport” (CO2RE), is benchmarked against its parent Euro V compliant CNG engine (reference) in terms of emissions and fuel consumption. The main technological innovation includes a new cylinder head equipped with a Variable Valve Actuation system designed to provide on the intake side a continuous fully flexible variation of the valve lift and timing. The newly developed engine was optimized for urban emission profiles and operation such as garbage collection purposes.
2015-09-06
Technical Paper
2015-24-2512
Barouch Giechaskiel, Alessandro Zardini, Giorgio Martini
In 2009 a particle number (PN) limit was introduced in the European Union vehicle exhaust legislation for diesel passenger cars. The PN method requires measurement of solid particles (i.e. those that do not evaporate at 350°C) above 23 nm. In 2013 the same approach was introduced in the heavy duty engines legislation. The same approach will be added for gasoline direct injection vehicles from 2017. This decision was based on a long evaluation that concluded that there is no significant sub23nm fraction for this technology. In this paper we examine the suitability of the current PN method for mopeds and motorcycles. Emission levels of >10 mopeds and motorcycles are presented. Special attention is given to sub23nm emission levels for some of them. The investigation was conducted with PN legislation compliant systems with counters measuring above 23nm and 10nm.
2015-09-06
Technical Paper
2015-24-2515
Christophe Barro, Sushant Pandurangi, Philipp Meyer, Konstantinos Boulouchos, Philipp Elbert, Yuri M. Wright
Past research has shown that post injections have the potential to reduce Diesel engine exhaust PM concentration without any significant influence in NOx emissions. However, an accurate, widely applicable rule of how to parameterize a post injection such that it provides a maximum reduction of PM emissions does not exist. Moreover, the underlying mechanisms are not thoroughly understood. In past research, the underlying mechanisms have been investigated in engine experiments, in constant volume chambers and also using detailed 3D CFD-CMC simulations. It has been observed that soot reduction due to a post injection is mainly due to two reasons: increased turbulence from the post injection during soot oxidation and lower soot formation due to lower amount of fuel in the main combustion at similar load conditions. Those studies do not show a significant temperature rise caused by the post injection.
2015-09-06
Technical Paper
2015-24-2514
Marco Piumetti, Samir Bensaid, Nunzio Russo
A set of nanostructured CeO2-based catalysts with different topological and textural properties (CeO2-nanocubes, CeO2-nanocubes over ZSM-5-type zeolite, CeO2-nanorods, mesoporous CeO2 and CeO2-SCS) has been prepared to investigate the shape-dependency activity of ceria towards soot combustion under different reaction. The physico-chemical properties of the prepared materials have been studied using complementary techniques. The best performances, in terms of the total oxidation of soot, have been achieved for the CeO2-nanocubes, due to the abundance of coordinative unsaturated atomic sites on the exposed surfaces. However, better results, in terms of the onset of soot oxidation, have been obtained for high-surface-area materials, thus reflecting the key role of surface area at low temperatures. Activity tests have suggested the surface-sensitivity of soot oxidation over the prepared ceria-based materials, when the reaction temperature was above 410 °C or 370 °C.
2015-09-06
Technical Paper
2015-24-2516
Panayotis Dimopoulos Eggenschwiler, Daniel Schreiber
Particulate matter (PM)in diesel exhaust is captured in diesel particulate filters (DPFs). Since increased PM load in the filter and thus increased pressure drop across the filter deteriorates the engine performance, the filter load of the DPF has to be removed during a process referred to as regeneration. Measures for successful regeneration aim at accelerating soot oxidation and increase fuel consumption. Regeneration lay-out and thus fuel consumption increase is strongly depending on the oxidation behavior of soot. The aim of the present study is the investigation of soot oxidation characteristics. Therefore particle filters have been loaded with soot using the exhaust gas of small heavy duty vehicle operated under defined conditions on an engine dynamometer. The particle filters have been then dismantled and fragmented on their constituting segments. Each filter segment has been regenerated individually in a specifically designed test bench.
2015-09-06
Technical Paper
2015-24-2521
José Ramón Serrano, Pedro Piqueras, Emanuele Angiolini, Cesare Meano, Joaquín De La Morena
The abatement of nitrogen oxides emissions is a topic of major concern for automotive manufacturers. In addition to aftertreatment solutions such as LNT or SCR devices, the use of exhaust gas recirculation (EGR) is necessary in most of the applications to meet emissions regulations. Due to the high specific humidity of the exhaust gases, a high condensate flow may be generated if EGR gases are significantly cooled down. In the case of long-route EGR (LR-EGR) usage, this condensate flow would reach the compressor wheel. This paper explores the variables governing the condensation process and the potential effects of the liquid droplets and streams on the compressor wheel durability combining experimental and theoretical approach. For this purpose, visualization of both the condensate flow and the compressor wheel are performed. Tests are conducted in a flow test rig in which LR-EGR water content is reproduced by water injection on the hot air mass flow.
2015-09-06
Technical Paper
2015-24-2543
Damien Maroteaux, Damien Le Guen, Eric Chauvelier
The worldwide trends for future CO2 regulation standards will push car manufacturers for more and more development of Electric and Hybrid Electric Vehicles. Many different configurations of Hybrid Electric Vehicles exist, including parallel hybrid, series hybrid, plug-in hybrids, Battery Electric Vehicles with Range Extender, etc. The choice of the optimal architecture depends on many different parameters, and is a key issue to be solved at the beginning of vehicle development. In order to help decision making in the early phase of projects, simulation tools are essential. A specific simulation platform for simulation of fuel economy and CO2 emissions for hybrid electric vehicles has been developed by Renault.
2015-09-06
Technical Paper
2015-24-2391
Dimitris Tsokolis, Stefanos Tsiakmakis, Georgios Triantafyllopoulos, Anastasios Kontses, Zisis Toumasatos, Georgios Fontaras, Athanasios Dimaratos, Biagio Ciuffo, Jelica Pavlovic, Alessandro Marotta, Zissis Samaras
The present paper describes the development of a standardized modelling approach to simulate the effect of the new Worldwide harmonised Light duty Test Procedure (WLTP) on the certified CO2 emissions of light duty vehicles. The European fleet has been divided into a number of representative segments based on specific vehicle characteristics and technologies. Representative vehicles for each segment were chosen. A test protocol has been developed in order to generate the necessary validation data for the simulation models which were developed subsequently. A standardized modelling procedure was adopted, in order to minimize the flexibilities and sources of uncertainty, which was based on the development of a reference "template model" to be used in the study. Subsequently, vehicle models were developed using AVL Cruise simulation software based on the abovementioned template model.
2015-09-06
Technical Paper
2015-24-2531
Marco Leonetti, Michael Bargende, Martin Kreschel, Christoph Meier, Horst Schulze
Due to the demands for today’s passenger cars regarding fuel consumption and emissions, exhaust turbo charging has become a fundamental step in achieving these goals. Especially in upper and middle class vehicles it is also necessary to consider the noise comfort. Today, floating bushings are mainly used as radial bearings in turbochargers. In the conventional operating range of the turbocharger dynamic instability occurs in the lubrication films of the bearings. This instability is transferred by structure-borne noise into audible airborne sound and known as constant tone phenomenon. This phenomenon is not the major contributor of the engine noise but its tonal character is very unpleasant. In order to gain a more detailed understanding about the origin of this phenomenon, displacement sensors have been applied to the compressor- and the turbine-side of the rotor, to be able to determine the displacement path.
2015-09-06
Technical Paper
2015-24-2509
Maria Vittoria Prati, Giovanni Meccariello, Livia Della Ragione, Maria Antonietta Costagliola
The aim of this study is to investigate the parameters influencing the real driving emission monitoring with particular attention towards the influence of road gradient. For this purpose, an experimental activity was carried out with a Euro 5 diesel light-duty vehicle, driven along two tracks of Naples characterized by different road gradient: the first pattern is quite flat, the second is in an area with variable altitude and includes positive (+2.9%) and negative (-3.6%) road gradient. Exhaust emissions of CO, THC, NOx, CO2 were acquired on road by using a portable emission measuring system (PEM) connected also to the Engine Control Unit for saving the main engine parameters and a GPS for the geographical coordinates and altitude. The acquired speed profiles were repeated on the chassis-dynamometer without simulating the road gradient.
2015-09-06
Technical Paper
2015-24-2497
Pierpaolo Napolitano, Carlo Beatrice, Chiara Guido, Nicola Del Giacomo, Leonardo Pellegrini, Pietro Scorletti
The present paper describes the results of a research activity aimed at studying the potential effects determined by the use of Hydrotreated Vegetable Oil (HVO) blends as fuels in modern diesel engines. Five fuels were tested on a light duty four-cylinder diesel engine, Euro 5 version, installed on a dyno test bench. The set of fuels comprised a commercial EN590-compliant diesel fuel and four experimental fuels formulated ad hoc to investigate the effect of the cetane provided by the HVO. The experimental campaign included both dynamic test conditions, running the engine along the New European Driving Cycles (NEDC), and steady-state operating engine points, six at partial speed/loads conditions, representative of the urban and extra-urban part of the engine homologation cycle, and one at full load condition at 3500 rpm engine speed.
2015-09-06
Technical Paper
2015-24-2433
Anders N. Johansson, Petter Dahlander
Among many techniques used for increasing fuel efficiency of a modern Gasoline Direct-Injected (GDI) engine are boosting and stratified operation. In modern downsized GDI engines, boosting is standard in order to achieve a high power output. Boosted GDI-engines have however mostly been operated in homogenous mode and little is known on the effects of operating a boosted GDI-engine in stratified mode. This study investigates the influence on combustion, standard emissions and particulate size distribution versus number in a Spray-Guided, Gasoline, Direct-Injected (SGDI), single cylinder, research engine operated with various levels of boost. The engine was operated in steady state mode at five engine operating points of various load and speed in the low to lower mid load range. The engine was boosted with an external Roots blower and operated at four levels of overpressure as well as under atmospheric pressure for comparison.
2015-09-06
Technical Paper
2015-24-2505
Maria Rosaria Gaballo, Maria Giodice, Alberto Diano, Fabio Fersini, Francesco Miccolis, Soenke Mannal, Stefan Motz
World of diesel becomes technically more and more complex due to the increasingly restrictive legislation e.g. with respect to emissions, fuel consumption and RDE (real driving emissions evaluations). Simulation provides a mechanism for the investigation and optimization of diesel engine performances, evaluation and investigation of innovative new engine concepts, RDE evaluation, after-treatment design and optimization, by that contributing to solve above mentioned challenges. Besides these generally valid capabilities of simulations our model development is focused additionally on the mission to use right sized models to reduce usage of resources and by that making simulation an even more rapid and cost effective method In this contribution we present our approach for simulation as an advanced integrated tool capable to answer challenging questions towards emission and fuel consumption reduction in future legislation frameworks.
2015-09-06
Technical Paper
2015-24-2501
Thomas Laible, Stefan Pischinger, Bastian Holderbaum
Today’s and future stringent emission limits require the use of exhaust gas aftertreatment technologies. In terms of legislation, the emissions at low engine load and at the cold start increasingly gain attention. At the Institute for Internal Combustion Engines RWTH Aachen University, different measures for rising the temperature concerning exhaust gas aftertreatment components on both the passenger car and the industrial / commercial vehicle engine. The proposed study of the passenger car diesel engine has shown the potential of internal and external heating measures. The configuration consisting of NSC and DPF, illustrates the potential of electrically heated NSC, including solutions on how the emission limit for EU6 can be achieved.
2015-09-06
Technical Paper
2015-24-2538
Lars Christian Riis Johansen, Ingemar Denbratt, Stina Hemdal
The emissions from a parallel hybrid combustion engine and electric powertrain on the NEDC and FTP75 drive cycles has been investigated in order to determine the relation between emissions and the road and engine load profile. The time resolved particulate number and size distribution was measured in addition to unburned hydrocarbons (UHC) and NOx. Cold and hot powertrain starts were conducted for both drive cycles. The combustion engine was a three cylinder spark ignited direct injection (SIDI) turbocharged engine fuelled with gasoline. Particulate emission peaked during acceleration from idling during both cold and hot drive cycle starts. Particulates during startup and acceleration from idling were characterized by particles smaller than 100nm. During periods of constant large engine load the particle numbers in the region of 100nm increased. UHC similarly peaked during acceleration from engine idling. NOx depended predominantly on engine load.
2015-09-06
Technical Paper
2015-24-2508
Joschka Schaub, Thorsten Schnorbus, Thomas Koerfer, Stefan Pischinger
Model-based control strategies along with an adapted calibration process become more important in the overall vehicle development process. The main drivers for this development trend are an increasing number of vehicle variants and more complex engine hardware, which is required to fulfill the more and more stringent emission legislation and fuel consumption targets. Upcoming fundamental changes in the homologation process with EU 6C covering an extended range of different ambient conditions are suspected to intensify this trend. One main cause for the increased calibration effort is the use of various aftertreatment technologies amongst different vehicle applications requiring numerous combustion modes. The different combustion modes range from heating modes for active Diesel Particulate Filter (DPF) regeneration or early SCR light-off and rich combustion modes to purge the NOx storage catalyst (NSC) to partially premixed normal combustion modes.
2015-09-06
Technical Paper
2015-24-2518
Riccardo Amirante, Elia Distaso, Paolo Tamburrano, Rolf D. Reitz
Due to the new challenge of meeting number-based regulations for particulate matter (PM), a numerical and experimental study has been conducted to better understand particulate formation in engines fuelled with compressed natural gas. The study has been conducted on a Heavy-Duty, Euro VI, 4-cylinder, spark ignited engine, with multipoint sequential phased injection and stoichiometric combustion. For the experimental measurements two different instruments were used: a condensation particle counter (CPC) and a fast-response particle size spectrometer (DMS) the latter able also to provide a particle size distribution of the measured particles in the range from 5 to 100 nm. Experimental measurements in both stationary and transient conditions were carried out. Then the influences of engine load and regime on particle size distribution (PSD) have been pointed out were determinated through the stationary analysis.
2015-09-06
Technical Paper
2015-24-2388
Jordan Rudloff, Alessio Dulbecco, Gregory Font
New generation Diesel engine becoming increasingly complex to be able to satisfy the always severer constraints on pollutant emissions, during the calibration phase of the engine, manufacturers have to account for a large number of variables to reach their targets expressed in terms of drivability, fuel consumption, in-cylinder pollutant emissions. Furthermore, due to the increasingly synergy between engine combustion chamber and exhaust after-treatment technologies, it is essential to consider global optimization approaches to obtain optimum conditions to meet high conversion efficiencies in after-treatment systems. In that context, engine system simulation approaches are very flexible tools that allow to create virtual innovative powertrains and perform, in a quite short time and with reduced cost, a large number of tests over a wide range of operating conditions. Moreover, they give access to detailed physical information, which is not easily available from experiments.
2015-09-06
Technical Paper
2015-24-2396
Philippe Moreau, Patricia Valerio, Alain Brillard, Valerie Tschamber, Jean-Francois Brilhac, Yves Hohl, Regis Vonarb, L. Germanese, B. Courtalon
We aim at presenting an experimental and modelling methodology developed at LGRE to characterize soot oxidation in the presence of different atmospheres (NO2, NO2/O2), simulating passive regeneration which occur in a Diesel Particulate Filter (DPF). The thermal reactivity of different types of soot has been studied and compared. Soot are produced from a prototype Liebherr engine and on an engine dynamometer at R&D Moteurs company, under two engine cycles (Specific Liebherr Machine Cycle and NRTC) and for three different fuels (EN590, B10, US). The experimental work was carried out in a fixed bed reactor, which allows simulating the conditions which prevail in a DPF. Small soot masses (15-30mg) were deposited on the quartz frit of the reactor and submitted to a gas flow (NO2 or NO2/O2), under different temperature ramps from 5°C/min to 50°C/min and in temperature ranges 200°C-900°C. The mole fractions of NO2, NO, CO2 and CO at the reactor outflow were measured by infrared analyzers.
2015-09-06
Technical Paper
2015-24-2517
Piotr Bielaczyc, Joseph Woodburn, Andrzej Szczotka
The particulates in vehicular exhaust are now under great scrutiny and are subject to legislative limits in many cases. In the EU, direct injection spark ignition (DI SI) engines running on petrol now have limits for particulate emissions set for both mass and number. It is widely acknowledged that current legislative laboratory test procedures in many ways represent a best-case scenario – more aggressive driving cycles and less favourable ambient conditions can increase particulate emissions massively. Ambient temperature is generally the environmental parameter of most importance regarding particulate emissions from an engine, particularly for the reasonably brief periods of operation typical for passenger cars operating from a cold start. Cold start events are challenging for internal combustion engines for various reasons, with multiple emissions impacts for all types of automotive engines.
2015-09-06
Technical Paper
2015-24-2504
Gerben Doornbos, Emma Adams, Per-Anders Carlsson, Daniel Dahl, Mats Laurell, Håkan Schyllander, Par Gabrielsson, Milica Folic, Ingemar Denbratt, Magnus Skoglundh
Commercial three way catalysts have limited capacity towards reducing NOx in the presence of excessive oxygen. This prevents lean-burn combustion concepts from meeting legislative emission standards. A solution towards decreasing NOx emissions in the presence of excess air is the use of a passive-SCR system. Under rich conditions ammonia is formed over an ammonia formation catalyst, the ammonia is stored in the SCR and in its turn reacts with the NOx under lean engine conditions. Here up-scaled Pt/Al2O3 and Pd/Al2O3 catalysts as well as a commercially Pd-Rh based three-way catalyst (TWC) are evaluated using both engine and further lab-scale tests. The purpose of these tests is to compare the ammonia production for the various catalysts under various lambda values and temperatures by means of engine and lab scale tests. The Pd/Al2O3 showed little sensitivity to temperature both under engine and lab scale experiments.
2015-09-06
Technical Paper
2015-24-2510
Jan Czerwinski, Pierre Comte, Martin Güdel, Andreas Mayer, Jacques Lemaire, Felix Reutimann, Adm Heinz Berger
As a result of increased use of catalytic exhaust aftertreatment systems of vehicles and the low-Sulfur Diesel fuels there is an increasing share of NO2 in the ambient air of several cities. This is in spite of lowering NOx. NO2 is much more toxic than NO and it will be specially considered in the next legal testing procedures. There are doubts about the accuracy of analyzing the reactive substances from diluted gas and this project has the objective to show how NO2 is are changing along the gas way of the exhaust- and the CVS systems. For legal measurements of NO2 a WLTP-DTP subgroup proposed different combinations of NOx-analyzers and analysis of NO and NOx. Some of these setups were tested in this work. The investigated WLTP – NO2-measuring methods have been found as useful tools to estimate the NO2-levels and there were no indications of reactivity at these low concentration levels.
2015-09-06
Technical Paper
2015-24-2448
Mengqin Shen, Vilhelm Malmborg, Yann Gallo, Bjorn B. O. Waldheim, Patrik Nilsson, Axel Eriksson, Joakim Pagels, Oivind Andersson, Bengt Johansson
The conventional diesel combustion offers high thermal efficiencies along with elevated emissions of oxides of nitrogen (NOx). Exhaust gas recirculation (EGR) is one of the possible ways that help to reduce NOx emissions but can generally result in higher engine-out soot emissions. To better understand the knowledge about particle formation and emission, an insight in the cylinder is necessary. In this work, characteristics of soot particles from in-cylinder gas in a heavy duty engine for low temperature combustion (LTC) compared with conventional combustion were investigated. By using a fast gas sampling valve, gas samples from the cylinder were taken as a function of crank angle and analyzed regarding the black carbon mass, soot particle size distribution and particle numbers. Black carbon mass was measured with an aethalometer and the particle size distribution and particle number were measured by a Scanning Mobility Particle Sizer (SMPS). Three levels of EGR were applied.
2015-09-06
Technical Paper
2015-24-2486
Ajay Singh Verma, M. Muzaffarul Hasan, Ashish Karnwal, Vipul Vibhanshu
The continuous growth of population and development of industries give rise to massive increase in the global energy demand in recent years. The timing of peak oil, serious social economic consequences and global decline in oil production may be avoided by use of unconventional alternative fuels. Therefore present work investigated the combustion and emission characteristics of an unmodified four stroke single cylinder variable compression ratio diesel engine utilizing isopropyl alcohol (2-propanol)-diethyl ether blends with diesel. In this study, the proportion of isopropyl alcohol was varied as 10%, 15% and 20% by volume while proportion of diethyl ether was kept constant as 5% by volume. The different fuel samples were prepared using 10% isopropyl, alcohol 5% diethyl ether by volume (IPD15), 15% isopropyl alcohol, 5% diethyl ether by volume (IPD20) and 20% isopropyl alcohol 5% diethyl ether by volume (IPD25) with neat standard diesel.
2015-09-06
Journal Article
2015-24-2479
Maximilian Malin, Vladimir Krivopolianskii, Bjørn Rygh, Vilmar Aesoy, Eilif Pedersen
Maritime environmental restrictions urge the need for cleaner emissions from shipping, by improved combustion processes, alternative cleaner fuels and exhaust gas cleaning. Alternative fuels, like bio fuel (fish oil), has a potential to reduce soot production during the combustion process and will be deeply investigated in this article. For this purpose a constant volume pre-combustion rig laboratory was build up in the last year and is used as a basic investigation tool for studying the fuel injection system (including investigation in combustion, spray development, fuel evaporation process and ignition delay) in engines. The focus of this study is to investigate the injector in full size, including experiments with multi nozzle injections, and with full optical access to the chamber. To generate similar injection condition in the combustion rig as in the internal combustion engine, the rig is heated up using a so called chemical heating process.
2015-09-06
Journal Article
2015-24-2389
Mirko Baratta, Roberto Finesso, Daniela Misul, Ezio Spessa
The potential of internal EGR (iEGR) and external EGR (eEGR) in reducing the engine-out NOx emissions in a heavy-duty diesel engine has been investigated by means of a refined 1D fluid-dynamic engine model developed in the GT-Power environment. The engine is equipped with Variable Valve Actuation (VVA) and Variable Geometry Turbocharger (VGT) systems. The activity was carried out in the frame of the CORE (CO2 Reduction for Long Distance Transport) Collaborative Project of the European Community, VII FP. The engine model integrates an innovative 0D predictive combustion model for the simulation of the HRR (heat release rate), which is based on the accumulated fuel mass approach, and a multi-zone thermodynamic model for the simulation of the in-cylinder temperatures. NOx emissions are calculated by means of the Zeldovich thermal and prompt mechanisms.
Viewing 1 to 30 of 22822

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