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Viewing 1 to 30 of 6707
2015-09-29
Technical Paper
2015-01-2832
Keith Friedman, John Hutchinson, Khahn Bui, Matthew Stephens, Alyssa Schmidt
The incidence of fire in heavy trucks has been shown to be about ten times higher under crash conditions than occurs in passenger vehicles. Fuel tank protection testing defined in J703 was originally issued in 1954. Advanced virtual testing of current and alternative fuel tank designs and locations under example representative impact conditions is reported.
2015-09-29
Technical Paper
2015-01-2814
Rakhesh Bharathan
Simultaneous reduction of NOx and PM from engine exhaust of a diesel engine is an interesting area of research due to the implementation of stringent emission regulations all over the world. Cost involved in expensive after treatment systems such as DPF and SCR necessitate minimization of engine out pollutants. With minimum engine out emission achieved through engine hardware and combustion parameter optimization, possibility of elimination or downsizing of the after treatment system can be explored. The paper presents the effect of fuel injection parameters and EGR rate on exhaust emission of a boosted diesel engine. Effects of parameters such as rail pressure, pilot-post injections, SOI, EGR rate and EGR temperature on a 4 cylinder two valve direct injection diesel engine is studied. Present study reveals the possibility of elimination of after treatment systems at BS IV level with optimization of engine hardware and combustion parameters.
2015-09-28 ...
  • September 28, 2015 (8:30 a.m. - 4:30 p.m.) - Troy, Michigan
  • April 15, 2016 (8:30 a.m. - 4:30 p.m.) - Detroit, Michigan
Training / Education Classroom Seminars
The improved efficiencies of the modern diesel engine have led to its increased use within the mobility industry. The vast majority of these diesel engines employ a high-pressure common rail fuel injection system to increase the engine's fuel-saving potential, emissions reduction, and overall performance. This one-day seminar will begin with a review of the basic principles of diesel engines and fuel injection systems. Diesel and alternative fuels will be discussed, followed by current and emerging diesel engine applications.
2015-09-15
Technical Paper
2015-01-2593
Jonathan L. Geisheimer, Michael Wabs, Carlos Carvalho
Time Domain Reflectometery (TDR) has been used for many years to find cable breaks and measure fluid levels in industrial processes. The technology uses picosecond level pulses and the associated reflection off of the fluid level surface in a time of flight measurement to determine fluid height. However, TDR signals have additional information that can be processed and exploited for IVHM applications. For example, when water collects in the fuel tank, TDR is capable of identifying and measuring the amount of water. This can allow for water sumps to be drained on condition instead of on a schedule. In addition, electromagnetic properties of the fluid can be determined, such as the dielectric constant and conductivity, which can be used to identify mis-fueling situations, contaminants in the fluid, and potentially other properties of fluid health.
2015-09-06
Technical Paper
2015-24-2432
Michela Costa, Paolo Sementa, Ugo Sorge, Francesco Catapano, Guido Marseglia, Bianca Maria Vaglieco
Knocking combustion in spark ignition engines is an abnormal combustion phenomenon strongly affecting performance and thermal efficiency. The possibility to have abnormal combustions in a GDI (gasoline direct injection) engine is linked to the outcome of the mixture formation process. Present work explores possible advantages deriving from the use of split injections in increasing the engine power output and reducing the tendency to knock. Due to the recent development of gasoline injection systems, multiple injections are today regarded as a valuable tool to improve the in-chamber evaporation process and simultaneously reduce undesired effects deriving from an excessive spray impact over walls. Combustion stability is enhanced, unburned hydrocarbons and soot emissions are limited.
2015-09-06
Technical Paper
2015-24-2475
Donghoon Kim, Choongsik Bae, Stephen Park
Three visualization methods, Schlieren, Shadowgraph, Mie-scattering, were applied to compare diesel and gasoline spray structures. Fuels were injected into the high pressure/high temperature chamber under the same in-cylinder pressure and temperature condition of low load in a GDCI (gasoline direct injection compression ignition) engine. Two injection pressures (20 and 40 MPa), two ambient pressures (4.2MPa and 1.7 MPa) and two ambient temperature (908 K and 677 K) were selected. Three images from different methods were overlapped to show liquid and vapor phases more clearly. Vapor development of two fuels were similar, but different liquid developments were shown. At the same injection pressure and ambient temperature, gasoline liquid propagated more shortly and disappeared rapidly than diesel liquid phase. At the low ambient temperature and pressure condition, gasoline and diesel sprays with higher injection pressure showed a longer liquid length due to higher spray momentum.
2015-09-06
Technical Paper
2015-24-2428
Ferdinando Taglialatela Scafati, Francesco Pirozzi, Salvatore Cannavacciuolo, Luigi Allocca, Alessandro Montanaro
Gasoline direct injection (GDI) combustion with un-throttled lean stratified operation allows to reduce engine toxic emissions and achieve significant benefits in terms of fuel consumption. However, use of gasoline stratified charges can lead to several problems, such as a high cycle-to-cycle variability and increased particle emissions. Use of multiple injection strategies allows to mitigate these problems, but it requires the injection of small fuel amounts forcing the traditional solenoid injectors to work in their “ballistic” region, where the correlation between coil energizing time and injected fuel amount becomes highly not linear. In the present work a closed-loop control system able to manage the delivery of small quantities of fuel has been introduced. The control system is based on a particular feature found on the coil voltage command signal during the de-energizing phase.
2015-09-06
Technical Paper
2015-24-2467
Alessandro Ferrari, Federica Paolicelli
Abstract A challenging task that is required to modern injection systems is represented by the enhanced control of the injected quantities, especially when small injections are considered, such as, pilot and main shots in the context of multiple injections. The propagation of the pressure waves triggered by the nozzle opening and closure events through the high-pressure hydraulic circuit can influence and alter the performance of the injection apparatus. For this reason, an investigation of the injection system fluid dynamics in the frequency domain has been proposed. A complete lumped parameter model of the high-pressure hydraulic circuit has been applied to perform a modal analysis. The visualization of the main vibration modes of the apparatus allows a detailed and deep comprehension of the system dynamics. Furthermore, the possible resonances, which are induced by the action of the external forcing terms, have been identified.
2015-09-06
Technical Paper
2015-24-2470
Daniel Pearce, Yannis Hardalupas, A.M.K.P Taylor
The measurement of the rate of fuel injection using a constant volume, fluid filled chamber and measuring the pressure change as a function of time due to the injected fluid (the so called “Zeuch” method) is an industry standard due to its simple theoretical underpinnings. Such a measurement device is useful to determine key timing and quantity parameters for injection system improvements to meet the evolving requirements of emissions, power and economy. This study aims to further the understanding of the nature of cavitation which could occur in the near nozzle region under these specific conditions of liquid into liquid injection using high pressure diesel injectors for heavy duty engines. The motivation for this work is to better understand the temporal signature of the pressure signals that arise in a typical injection cycle.
2015-09-06
Technical Paper
2015-24-2473
Alessandro Montanaro, Luigi Allocca, Giovanni Meccariello, Maurizio Lazzaro
Abstract In internal combustion engines, the direct injection at high pressures produces a strong impact of the fuel on the combustion chamber wall, especially in small-bore sizes used for passenger cars. This effect is relevant for the combustion process resulting in an increase of the pollutant emissions and in a reduction of the engine performances. This paper aims to report the effects of the injection pressure and wall temperature on the macroscopic behavior and atomization of the impinging sprays on the wall. The gasoline spray-wall interaction was characterized inside an optically accessible quiescent chamber using a novel make ready Z-shaped schlieren-Mie scattering set-up using a high-speed C-Mos camera as imaging system. The arrangement was capable to acquire alternatively the schlieren and Mie-scattering images in a quasi-simultaneous fashion using the same line-of-sight.
2015-09-06
Technical Paper
2015-24-2480
Lucio Postrioti, Maurizio Bosi, Andrea Cavicchi, Fakhry AbuZahra, Rita Di Gioia, Giovanni Bonandrini
Direct Injection technology for Spark Ignition engines is currently undergoing a significant development process in order to achieve its complete potential in terms of fuel conversion efficiency, while preserving the ability to achieve future, stringent emission limits. In this process, improving the fuel spray analysis capabilities is of primary importance. Among the available experimental techniques, the momentum flux measurement is one of the most interesting approaches as it allows a direct measurement of the spray-air mixing potential and hence it is currently considered an interesting complement to spray imaging and Phase Doppler Anemometry. The aim of the present paper is to investigate the fuel spray evolution when it undergoes flash boiling, a peculiar flow condition occurring when the ambient pressure in which the spray evolves is below the saturation pressure of the injected fluid.
2015-09-06
Technical Paper
2015-24-2477
Ezio Mancaruso, Renato Marialto, Luigi Sequino, Bianca Maria Vaglieco, Massimo Cardone
Abstract Blends of propane-diesel fuel can be used in direct injection diesel engines to improve the air-fuel mixing and the premixed combustion phase, and to reduce pollutant emissions. The potential benefits of usinf propane in diesel engines are both environmental and economic; furthermore, its use does not require changes to the compression ratio of conventional diesel engines. The present paper describes an experimental investigation of the injection process for different liquid preformed blends of propane-diesel fuel in an optically accessible Common Rail diesel engine. Slight modifications of the injection system were required in order to operate with a blend of propane-diesel fuel. Pure diesel fuel and two propane-diesel mixtures at different mass ratios were tested (20% and 40% in mass of propane named P20 and P40). First, injection in air at ambient temperature and atmospheric pressure were performed to verify the functionality of the modified Common Rail injection system.
2015-09-06
Technical Paper
2015-24-2455
Slavey Tanov, Zhenkan Wang, Hua Wang, Mattias Richter, Bengt Johansson
Partially Premixed Combustion (PPC) is used to meet the increasing demands of emission legislation and to improve fuel efficiency. PPC with gasoline fuels has the advantage of a longer premixed duration of fuel/air mixture which prevents soot formation. To achieve a longer ignition delay, which increases the overall combustion stability, different fuel injection strategies were applied. In this work, the effect of multiple injections and variable flow swirl on the generation of in-cylinder turbulence were investigated. High-speed Particle Image Velocimetry (PIV) is conducted to an optical Direct Injection (DI) engine to obtain the turbulence structure during fired conditions. PRF 70 (30% n-heptane and 70% iso-octane) was used as PPC fuel. The quartz piston retains a realistic bowl geometry in order to maintain the in-cylinder flow as similar as possible to the flow which would exist in a production engine.
2015-09-06
Technical Paper
2015-24-2454
Zhenkan Wang, Slavey Tanov, Hua Wang, Mattias Richter, Bengt Johansson, Marcus Alden
It has been proven that Partially Premixed Combustion (PPC) has the capability of high combustion efficiency with low soot and NOx emissions, which meet the requirements of extremely restricted emission regulations. In order to obtain more homogenous combustion and longer ignition delay in PPC, which leads more smooth combustion, different fuel injection strategies were employed which could affect the fuel air mixing and control the combustion. In this work, a light duty optical engine was used to conduct high-speed particle image velocimetry (PIV) for single, double and triple injections at different start of injection (SOI) timings. A quartz piston and a cylinder liner were installed in Bowditch configuration to enable optical access. The geometry of the quartz piston crown is based on the standard diesel combustion chamber design for this passenger car engine, including a re-entrant bowl shape.
2015-09-06
Technical Paper
2015-24-2459
Francesco Catapano, Silvana Di Iorio, Paolo Sementa, Bianca Maria Vaglieco
The increasing concerns on the global environment issues and on the depletion of fossil fuel reserves have been driving to searching sustainable and environmental friendly fuels. Methane is one of the alternative fuels for addressing these issues. The potential of methane in improving the engine performance was fully exploited when blended with hydrogen or dual fueled with gasoline. In this paper a methane-assisted gasoline injection in a small displacement GDI SI engine was analyzed. Typically, the air-assisted fuel injection system was applied to supply assistant air for the atomization of injected fuel. This configuration allows improving the gasoline combustion thanks not only to the assisted injection, which improves the fuel atomization and consequently the homogenization of the charge, but also to the presence of the methane and its chemical interaction with gasoline heavy hydrocarbon, which allows a more efficient combustion.
2015-09-06
Technical Paper
2015-24-2471
Federico Pellegrino, Alessio Dulbecco, Denis Veynante
One of the major objectives of today’s automotive industry is the reduction of pollutant emissions and the increase of the overall efficiency of the powertrain, leading to the development of new concepts of internal combustion engine. The well-known advantages of charge stratification in ultra-lean gasoline engines and engine downsizing suggest that an increase in the diffusion of Direct-Injection Spark-Ignition (DI-SI) engines is foreseeable in the near future. System simulation is a powerful tool to reproduce the behaviour of the powertrain as a whole, since it allows to investigate the interactions between the different components in both stable and transient conditions. Such a global approach can be exploited effectively only if the relevant physical phenomena are correctly reproduced.
2015-09-06
Technical Paper
2015-24-2499
Fabio Berni, Sebastiano Breda, Alessandro D'Adamo, Stefano Fontanesi, Giuseppe Cantore
A new generation of highly downsized SI engines with specific power outputs around or above 150 HP/liter is emerging in the sport car market sector. Technologies such as high-boosting, direct injection and downsizing are adopted to increase power density and reduce fuel consumption. To counterbalance the increased risks of pre-ignition, knock or mega-knock, currently made turbocharged SI engines usually operate with high fuel enrichments and delayed (sometimes negative) spark advances. The former is responsible for high fuel consumption levels, while the latter induce an even lower A/F ratio (below 11), to limit the turbine inlet temperature, with huge negative effects on BSFC. A possible solution to increase knock resistance is investigated in the paper by means of 3D-CFD analyses: water/methanol emulsion is port-fuel injected to replace mixture enrichment while preserving, if not improving, indicated mean effective pressure and knock safety margins.
2015-09-06
Journal Article
2015-24-2502
Yujun Liao, Panayotis Dimopoulos Eggenschwiler, Alexander Spiteri, Lorenzo Nocivelli, Gianluca Montenegro, Konstantinos Boulouchos
The injection process of urea-water solution (AdBlue) determines initial conditions for reactions and catalysis and is fundamentally responsible for optimal operation of selective catalytic reduction (SCR) systems. The spray characteristics of four, commercially available, injectors (one air-assisted and three pressure-driven with different nozzle-hole configurations) are investigated with non-intrusive measuring techniques. Injection occurred in the crossflow of a channel blowing preheated air in an exhaust duct similar configuration. The effect of several gas temperatures and flows on the spray propagation and entrainment has been extensively studied by shadow imaging. Shadow images, in addition, show that the spray of the pressure-driven injectors is only marginally affected by the gas crossflow. In contrast, the air assisted spray is strongly deflected by the gas, the effect increasing with increasing gas flow.
2015-09-06
Journal Article
2015-24-2464
Daniele Farrace, Ronny Panier, Martin Schmitt, Konstantinos Boulouchos, Yuri M. Wright
Large Eddy Simulations (LES) provide instantaneous values indispensable to conduct statistical studies of relevant fluctuating quantities for diesel sprays. However, numerous realizations are generally necessary for LES to derive statistically averaged quantities necessary for validation of the numerical framework by means of measurements and for conducting sensitivity studies, leading to extremely high computational efforts. In this context, the aim of this work is to explore and validate alternatives to the simulation of 20-50 single realizations at considerably lower computational costs, by taking advantage of the axisymmetric geometry and the Quasi-Steady-State (QSS) condition of the near nozzle flow at a certain time after start-of-injection (SOI).
2015-09-06
Technical Paper
2015-24-2395
Xavier Tauzia, Alain Maiboom, Guanqin Ma
In this paper, a new 1D combustion model is presented. It is expected to combine good predictive capacities with a contained CPU time, and could be used for engine design. It relies on a eulerian approach, based on Musculus 1D transient spray model. The latter has been extended to model vaporizing, reacting sprays. The general features of the model are first presented. Then various sub models (spray angle and dilatation, vaporization, thermodynamic properties) are detailed. Chemical kinetics are described with a global scheme to keep computational time low. The spray discretization (mesh) and angle model are first discussed through a sensitivity analysis. The model results are then compared to experiments from ECN data base (SANDIA) realized in constant volume bombs, for both inert and reacting cases. Some detailed analysis of model results are performed, including comparisons of vaporizing and non-vaporizing cases, as well as inert and reacting cases.
2015-09-06
Technical Paper
2015-24-2421
Federico Stola, Domenico Paolino, Marco Parotto, Fabio Troina
Current market drivers for automotive and light commercial engines and powertrain systems are mainly the new CO2 emission regulations all over the world and the pollutant emission reduction in the emerging markets, at minimal system cost. For both reasons, the adoption of a regulated electric low pressure fuel pump is very advantageous for electronically controlled diesel systems, customized for the emerging markets. Usually, the fuel delivery is performed at the maximum flow rate and a pressure regulator discharges the exceeding fuel amount from the rail or upstream the high pressure pump. At part load, the electric feed pump flow is higher than the request for engine power generation. For the purpose of this paper, the low pressure fuel pump is controlled for fuel delivery according to the engine request (reduced fuel consumption), thus avoiding the use of a pressure regulator valve (reduced cost).
2015-09-06
Technical Paper
2015-24-2406
Gyujin Kim, Kyoungdoug Min
Abstract The flamelet model is a widely used combustion model that demonstrates a good prediction of non-premixed combustion. In this model, the chemical time scales are considered to be smaller compared to those of the turbulence, which allows the heat and mass transfer equation to be decoupled from the flow equation. However, the model's dependency on the mixture fraction limits the combustion analysis to a single injection. To overcome this limitation, a two dimensional flamelet model, which uses two mixture fraction variables, was introduced to represent the non-premixed combustion of multiple injections. However, the model's computational time drastically increased due to the expansion of the solution domain. Thus, a modified 2-D flamelet model was introduced to reduce the computational time of the two dimensional flamelet model.
2015-09-06
Technical Paper
2015-24-2411
Carmelina Abagnale, Maria Cristina Cameretti, Umberto Ciaravola, Raffaele Tuccillo, Sabato Iannaccone
The dual-fuel (diesel/natural gas, NG) concept represents a solution to reduce emissions from diesel engines by using natural gas as an alternative fuel. As well known, the dual-fuel technology has the potential to offer significant improvements in the emissions of carbon dioxide from light-duty compression ignition engines. A further important requirement of the DF operation in automotive engines is a satisfactory response in a wide range of load levels. In particular, the part-load levels could present more challenging conditions for an efficient combustion development, due to the poor fuel/air ratio. Basing on the above assumptions, the authors discuss in this article the results of a combined numerical and experimental study on the effect of different injection timings on performance and pollutant fractions of a common rail diesel engine supplied with natural gas and diesel oil.
2015-09-06
Technical Paper
2015-24-2408
Nicola Giovannoni, Sebastiano Breda, Stefano Paltrinieri, Alessandro D'Adamo, Stefano Fontanesi, Francesco Pulvirenti
Abstract In spark-ignited direct-injected engines, the formation of fuel pools on the piston is one of the major promoters of unburnt hydrocarbons and soot: in order to comply with the increasingly stringent emission regulations (EU6 and forthcoming), it is therefore necessary to limit fuel deposit formation. The combined use of advanced experimental techniques and detailed 3D-CFD simulations can help to understand the mechanisms driving fuel pool formation. In the paper, a combined experimental and numerical characterization of pool formation in a GDI engine is carried out to investigate and understand the complex interplay of all the mentioned factors. In particular, a low-load low-rpm engine operation is investigated for different ignition phasing, and the impact of both fuel formulation and instantaneous piston temperature variations in the CFD analyses are evaluated.
2015-09-06
Technical Paper
2015-24-2398
Ivan Arsie, Roberto Di Cianni, Rocco Di Leo, Cesare Pianese, Matteo De Cesare
Abstract Nowadays the high competition reached by the automotive market forces Original Equipment Manufacturers (OEMs) towards innovative solutions. Strict emission standards and fuel economy targets make the work hard to be accomplished. Therefore modern engines feature complex architecture and embed new devices for Exhaust Gas Recirculation (EGR), turbocharging (e.g. multi-stage compressors), gas after-treatment (e.g. the Selective Catalyst Reduction (SCR)) and fuel injection (either high or low pressure). In this context the Engine Management System (EMS) plays a fundamental role to optimize engine operation. The paper deals with fuel spray and combustion simulation by a multi-zone phenomenological model aimed at the steady-state optimal tuning of the injection pattern.
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