Criteria

Text:
Topic:
Display:

Results

Viewing 1 to 30 of 6694
2015-09-28 ...
  • September 28, 2015 (8:30 a.m. - 4:30 p.m.) - Troy, 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.
2015-09-06
Technical Paper
2015-24-2406
Gyujin Kim, Kyoungdoug Min
Development of injection technologies such as common-rail direct injection allows multiple injection strategy in Diesel Engine, which can reduce emissions, noises and vibrations. Meanwhile, three dimensional combustion model using CFD can be a good apparatus to visualize the in-cylinder phenomena. RIF (Representative Interactive Flamelet) model shows a good prediction of non-premixed combustion. In RIF model, chemical time scales are considered to be smaller than those of turbulence, which can decouple the equations of heat and mass transfer from flow equations. Furthermore, theses governing equations can be described by one conserved scalar which is called mixture fraction by using the assumption that the flame is sufficient to thin in the direction orthogonal to the flame surface. However, its dependency on the mixture fraction set a limit on the combustion analysis for the single injection.
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
2015-24-2428
Ferdinando Taglialatela Scafati, Francesco Pirozzi, Salvatore Cannavacciuolo, Luigi Allocca, Alessandro Montanaro
Future emission regulations require the development of gasoline combustion engines with improved efficiency in order to obtain, other than a strong reduction of the toxic emissions, also a reduction of fuel consumption and hence carbon dioxide emissions. The greatest fuel consumption benefit is achieved by means of systems such as the gasoline direct injection combustion with unthrottled lean stratified operation. In this mode, the fuel is injected later in the compression stroke allowing stable combustion of ultra-lean mixtures. However, use of gasoline stratified charges can lead to several problems. In particular, due to the excess oxygen in the combustion stroke, the NOx emission levels are generally higher than in a PFI engine or homogeneous charge direct injection. Moreover, short time for mixture preparation and spray wall impingements are responsible for high cycle-to-cycle variability and high particle emissions.
2015-09-06
Technical Paper
2015-24-2467
Alessandro Ferrari, Federica Paolicelli
The modal analysis of a Common Rail fuel injection system equipped with solenoid injectors of the latest generation has been performed in the frequency domain. A complete lumped parameter model of the high-pressure hydraulic circuit from the pump delivery to the injector nozzles has been realized and validated by comparison with the frequency modal values obtained by applying a peak-picking technique to the measured pressure time history. Three main modal motions have been identified in the considered injection apparatus and the possible resonances with the external forcing terms, i.e., pump delivered flow-rate, pressure control valve discharged flow-rate and flow-rates expelled by the solenoid injector, have been highlighted and discussed. Furthermore, a sensitivity analysis of the frequency domain performance to key geometrical features of the high-pressure system layout has been carried out.
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
2015-24-2466
Tim Lackmann, Alan kerstein, Michael Oevermann
To further improve engines in terms of both efficiency and emissions many new combustion concepts are currently being investigated. Examples include homogeneous charge compression ignition (HCCI), stratified charge compression ignition (SCCI), lean stratified premixed combustion, and high levels of exhaust gas recirculation (EGR) in diesel engines. All of these combustion concepts have in common that the typical combustion temperatures are lower than in traditional spark ignition or diesel engines. To further improve and to develop combustion concepts for clean and high efficient engines, it is necessary to develop new computational tools and combustion models which can be used under non-standard conditions such as low temperature combustion. In this study a regime-independent combustion modeling strategy for non-premixed combustion is used to simulate a spray combustion process. The name of the recently developed model is RILEM (Representative Interactive Linear Eddy Model).
2015-09-06
Technical Paper
2015-24-2453
Abdul Rahman K, A Ramesh
Diesel fuelled HCCI (Homogeneous Charge Compression Ignition) engines experience advanced heat release rates and high HC emissions. However, gaseous fuel like biogas and hydrogen that have high self ignition temperatures have been used to effectively retard the combustion process in diesel fuelled HCCI engines. Since gaseous fuels form homogeneous mixtures more readily as compared to diesel they also can lower the HC and smoke emissions in HCCI engines. In biogas diesel HCCI engines the homogeneity of the diesel which is influenced by the injection process significantly affects combustion and performance. This work focuses on the influence of injecting diesel in two pulses in a Biogas Diesel HCCI (BDHCCI) engine as against injecting it in a single pulse. Comparisons have also been made with the Dual Fuel mode of operation at the same output under different biogas to diesel energy ratios.
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
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 viable solution to reduce emissions from diesel engines by using natural gas as an alternative fuel. The dual fuel operation is characterized by a diesel pilot injection to activate the combustion of NG that has been premixed with air in the intake port. 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. In these small-displacement high-speed engines, where the combustion event can be temporally shorter, the injection timing can exert an important effect on the performance and emissions of the engine. 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.
2015-09-06
Technical Paper
2015-24-2473
Alessandro Montanaro, Luigi Allocca, Giovanni Meccariello, Maurizio Lazzaro
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
2015-24-2432
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
2015-24-2436
Randy Hessel, Rolf D. Reitz, Zongyu Yue, Mark P. B. Musculus, Jacqueline O'Connor
The major topics of this paper are: to validate CFD estimates of in-cylinder soot distribution to soot natural luminosity measurements in a single-cylinder, optically-accessible research engine utilizing close-coupled post-injections; to visualize and quantify how post-injections disrupt and alter the progression of main-injection initiated soot; and to use full-3D CFD results to help interpret line-of-sight integrated soot-natural-luminosity measurements. The first stage effort at modeling these post-injection experiments is summarized in SAE Technical Paper 2014-01-1256. A major contribution of that work is the ability to visualize and quantify soot formation, oxidation and net-soot as distinct quantities. These capabilities are important, because they allow detailed analysis of CFD results so that the root causes of engine-out soot can be evaluated on a fundamental level. The current work augments the previous in at least three important ways, as is described next.
2015-09-06
Technical Paper
2015-24-2472
Nikolaos Papadopoulos, Pavlos Aleiferis
The design of a Diesel injector is a key factor in achieving higher engine efficiency. The injector’s fuel atomisation characteristics are also critical for minimising toxic emissions such as unburnt Hydrocarbons (HC). However, when developing injection systems, the small dimensions of the nozzle render optical experimental investigations very challenging under realistic engine conditions. Therefore, Computational Fluid Dynamics (CFD) can be used instead. For the present work, transient, Volume Of Fluid (VOF), multiphase simulations of the flow inside and immediately downstream of a real-size multi-hole nozzle were performed, during and after the injection event with a small air chamber coupled to the injector downstream of the nozzle exit. A Reynolds Averaged Navier-Stokes (RANS) approach was used to account for turbulence. Grid dependency studies were performed with 200k–1.5M cells.
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
2015-24-2471
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
2015-24-2480
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 achievement of 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
2015-24-2395
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
2015-24-2398
Ivan Arsie, Roberto Di Cianni, Rocco Di Leo, Cesare Pianese, Matteo De Cesare
Nowadays the high competition reached by the automotive market forces 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 EGR, turbocharging (e.g. multi-stage compressors), gas after-treatment (e.g. 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. The fuel spray model simulates the fuel-air mixture formation, the in-cylinder gas mixture evolution and accounts for fuel-wall impingement, which usually occurs in case of low-medium injection pressure or advanced injection timing.
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
2015-24-2455
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
2015-24-2459
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
2015-24-2470
Daniel Pearce, Yannis Hardalupas, A.M.K.P Taylor
ABSTRACT
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
Technical Paper
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).
2015-08-24 ...
  • August 24-25, 2015 (8:30 a.m. - 4:30 p.m.) - Troy, Michigan
  • December 8-9, 2015 (8:30 a.m. - 4:30 p.m.) - Norwalk, California
Training / Education Classroom Seminars
As diesel engines become more popular, a fundamental knowledge of diesel technology is critical for anyone involved in the diesel engine support industry. This course will explain the fundamental technology of diesel engines starting with a short but thorough introduction of the diesel combustion cycle, and continue with aspects of engine design, emission control design, and more. An overview of developing technologies for the future with a comprehensive section on exhaust aftertreatment is also included. The text, Diesel Emissions and Their Control, authored by Magdi Khair and W. Addy Majewski is included with the seminar.
Viewing 1 to 30 of 6694

Filter

  • Range:
    to:
  • Year: