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Viewing 181 to 210 of 33425
2017-09-04
Technical Paper
2017-24-0071
Fadila Maroteaux, Bianca Maria Vaglieco
Abstract Ignition delay time is key to any hydrocarbon combustion process. In that sense, this parameter has to be known accurately, and especially for internal combustion engine applications. Combustion timing is one of the most important factors influencing overall engine performances like power output, combustion efficiency, emissions, in-cylinder peak pressure, etc. In the case of low temperature combustion (LTC) mode (e.g. HCCI mode), this parameter is controlled by chemical kinetics. In this paper, an ignition delay time model including 7 direct reactions and 13 species coupled with a temperature criterion is described. This mechanism has been obtained from the previous 26-step n-heptane reduced mechanism, focusing on the low temperature region which is the most important phase during the two stage combustion process. The complete model works with 7 reactions until the critical temperature is reached, leading to the detection of the ignition delay time value.
2017-09-04
Technical Paper
2017-24-0090
Robert E. Morgan, Morgan Heikal, Emily Pike-Wilson
Abstract Traffic related NOx and particle emission remain a significant concern particularly in the urban environment. Electrification offers a medium to long term solution, but there remains a need to significantly reduce internal combustion engine emissions in the short and medium term, and potentially in the long term for long range inter city transportation. Late injection low temperature combustion (LTC) has the potential to achieve ultra-low emissions levels in a compression ignition engine by increasing the lean pre-mixed burn fraction. However, significant quantities of diluent are normally required to achieve the required delay in ignition and pre-mixing to achieve LTC. This results in high boost requirements, increased pumping work and the complexity of the air handling system and potentially adversely impacting fuel economy.
2017-09-04
Technical Paper
2017-24-0084
Giacomo Belgiorno, Nikolaos Dimitrakopoulos, Gabriele Di Blasio, Carlo Beatrice, Martin Tuner, Per Tunestal
Abstract In this paper, a parametric analysis on the main engine calibration parameters applied on gasoline Partially Premixed Combustion (PPC) is performed. Theoretically, the PPC concept permits to improve both the engine efficiencies and the NOx-soot trade-off simultaneously compared to the conventional diesel combustion. This work is based on the design of experiments (DoE), statistical approach, and investigates on the engine calibration parameters that might affect the efficiencies and the emissions of a gasoline PPC. The full factorial DoE analysis based on three levels and three factors (33 factorial design) is performed at three engine operating conditions of the Worldwide harmonized Light vehicles Test Cycles (WLTC). The pilot quantity (Qpil), the crank angle position when 50% of the total heat is released (CA50), and the exhaust gas recirculation (EGR) factors are considered. The goal is to identify an engine calibration with high efficiency and low emissions.
2017-09-04
Technical Paper
2017-24-0105
Stefania Falfari, Gian Marco Bianchi, Giulio Cazzoli, Claudio Forte PhD, Sergio Negro
Abstract The primary target of the internal combustion engines design is to lower the fuel consumption and to enhance the combustion process quality, in order to reduce the raw emission levels without performances penalty. In this scenario the direct injection system plays a key role for both diesel and gasoline engines. The spray dynamic behaviour is crucial in defining the global and the local air index of the mixture, which in turns affects the combustion process development. At the same time it is widely recognized that the spray formation is influenced by numerous parameters, among which also the cavitation process inside every single hole of the injector nozzle. The proper prediction of the cavitation development inside the injector nozzle holes is crucial in predicting the liquid jet emerging from them.
2017-09-04
Technical Paper
2017-24-0103
Marlene Wentsch, Marco Chiodi, Michael Bargende
Abstract Main limiting factor in the application of 3D-CFD simulations within an engine development is the very high time demand, which is predominantly influenced by the number of cells within the computational mesh. Arbitrary cell coarsening, however, results in a distinct distortion of the simulation outcome. It is rather necessary to adapt the calculation models to the new mesh structure in order to ensure reliability and predictability of the 3D-CFD engine simulation. In the last decade, a fast response 3D-CFD tool was developed at FKFS in Stuttgart. It aims for a harmonized interaction between computational mesh, implemented calculation models and defined boundary conditions in order to enable fast running simulations for engine development tasks. Their susceptibility to errors is significantly minimized by various measures, e.g. extension of the simulation domain (full engine) and multi-cycle simulations.
2017-09-04
Technical Paper
2017-24-0101
Pedro Marti-Aldaravi, Kaushik Saha, Jaime Gimeno, Sibendu Som
Abstract Actual combustion strategies in internal combustion engines rely on fast and accurate injection systems to be successful. One of the injector designs that has shown good performance over the past years is the direct-acting piezoelectric. This system allows precise control of the injector needle position and hence the injected mass flow rate. Therefore, understanding how nozzle flow characteristics change as function of needle dynamics helps to choose the best lift law in terms of delivered fuel for a determined combustion strategy. Computational fluid dynamics is a useful tool for this task. In this work, nozzle flow of a prototype direct-acting piezoelectric has been simulated by using CONVERGE. Unsteady Reynolds-Averaged Navier-Stokes approach is used to take into account the turbulence. Results are compared with experiments in terms of mass flow rate. The nozzle geometry and needle lift profiles were obtained by means of X-rays in previous works.
2017-09-04
Technical Paper
2017-24-0098
Christophe Barro, Curdin Nani, Richard Hutter, Konstantinos Boulouchos
Abstract The operation of dual fuel engines, operated with natural gas as main fuel, offers the potential of substantial savings in CO2. Nevertheless, the operating map area where low pollutant emissions are produced is very narrow. Especially at low load, the raw exhaust gas contains high concentrations of unburned methane and, with high pilot fuel portions due to ignition limitations, also soot. The analysis of the combustion in those conditions in particular is not trivial, since multiple combustion modes are present concurrently. The present work focuses on the evaluation of the individual combustion modes of a dual fuel engine, operated with natural gas as main and diesel as pilot fuel, using a combustion model. The combustion has been split in two partwise concurrent combustion phases: the auto-ignition phase and the premixed flame propagation phase.
2017-09-04
Technical Paper
2017-24-0093
Lorenzo Bartolucci, Stefano Cordiner, Vincenzo Mulone, Vittorio Rocco
Abstract Using natural gas in internal combustion engines (ICEs) is emerging as a promising strategy to improve thermal efficiency and reduce exhaust emissions. One of the main benefits related to the use of this fuel is that the engine can be run with lean mixtures without compromising its performances. However, as the mixture is leaned out beyond the Lean Misfire Limit (LML), several technical problems are more likely to occur. The flame propagation speed gradually decreases, leading to a slower heat release and a low combustion quality, thus increasing the occurrence of misfiring and incomplete combustions. This in turn results in a sharp increment in CO and UHC emissions, as well as in cycle-to-cycle variability. In order to limit the above-mentioned problems, different solutions have been proposed over the last decade.
2017-09-04
Technical Paper
2017-24-0121
Ivan Arsie, Giuseppe Cialeo, Federica D'Aniello, Cesare Pianese, Matteo De Cesare, Luigi Paiano
Abstract In the last decades, NOx emissions legislations for Diesel engines are becoming more stringent than ever before and the selective catalytic reduction (SCR) is considered as the most suitable technology to comply with the upcoming constraints. Model-based control strategies are promising to meet the dual objective of maximizing NOx reduction and minimizing NH3 slip in urea-selective catalytic reduction. In this paper, a control oriented model of a Cu-zeolite urea-SCR system for automotive diesel engines is presented. The model is derived from a quasi-dimensional four-state model of the urea-SCR plant. To make it suitable for the real-time urea-SCR management, a reduced order one-state model has been developed, with the aim of capturing the essential behavior of the system with a low computational burden. Particularly, the model allows estimating the NH3 slip that is fundamental not only to minimize urea consumption but also to reduce this unregulated emission.
2017-09-04
Technical Paper
2017-24-0119
Jos Feijen, Gerard Klink, Ed Jong, Andreas Schmid, Niels Deen, Michael Boot
Abstract Second generation biomass is an attractive renewable feedstock for transport fuels. Its sulfur content is generally negligible and the carbon cycle is reduced from millions to tens of years. One hitherto non-valorized feedstock are so-called humins, a residual product formed in the conversion of sugars to platform chemicals, such as hydroxymethylfurfural and methoxymethylfurfural, intermediates in the production of FDCA, a building block used to produce the polyethylene furanoate (PEF) bottle by Avantium. The focus of this study is to investigate the spray combustion behavior of humins as a renewable alternative for heavy fuel oil (HFO) under large two-stroke engine-like conditions in an optically accessible constant volume chamber.
2017-09-04
Technical Paper
2017-24-0113
Ezio Mancaruso, Luigi Sequino, Bianca Maria Vaglieco, Maria Cristina Cameretti
Abstract The management of multiple injections in compression ignition (CI) engines is one of the most common ways to increase engine performance by avoiding hardware modifications and after-treatment systems. Great attention is given to the profile of the injection rate since it controls the fuel delivery in the cylinder. The Injection Rate Shaping (IRS) is a technique that aims to manage the quantity of injected fuel during the injection process via a proper definition of the injection timing (injection duration and dwell time). In particular, it consists in closer and centered injection events and in a split main injection with a very small dwell time. From the experimental point of view, the performance of an IRS strategy has been studied in an optical CI engine. In particular, liquid and vapor phases of the injected fuel have been acquired via visible and infrared imaging, respectively. Injection parameters, like penetration and cone angle have been determined and analyzed.
2017-09-04
Technical Paper
2017-24-0107
Alessandro Montanaro, Luigi Allocca, Vittorio Rocco, Michela Costa, Daniele Piazzullo
Abstract Gasoline direct injection (GDI) engines are characterized by complex phenomena involving spray dynamics and possible spray-wall interaction. Control of mixture formation is indeed fundamental to achieve the desired equivalence ratio of the mixture, especially at the spark plug location at the time of ignition. Droplet impact on the piston or liner surfaces has also to be considered, as this may lead to gasoline accumulation in the liquid form as wallfilm. Wallfilms more slowly evaporate than free droplets, thus leading to local enrichment of the charge, hence to a route to diffusive flames, increased unburned hydrocarbons formation and particulate matter emissions at the exhaust. Local heat transfer at the wall obviously changes if a wallfilm is present, and the subtraction of the latent heat of vaporization necessary for secondary phase change is also an issue deserving a special attention.
2017-09-04
Technical Paper
2017-24-0146
Vincent Raimbault, Jerome Migaud, David Chalet, Michael Bargende, Emmanuel Revol, Quentin Montaigne
Abstract Upcoming regulations and new technologies are challenging the internal combustion engine and increasing the pressure on car manufacturers to further reduce powertrain emissions. Indeed, RDE pushes engineering to keep low emissions not only at the bottom left of the engine map, but in the complete range of load and engine speeds. This means for gasoline engines that the strategy used to increase the low end torque and power by moving out of lambda one conditions is no longer sustainable. For instance scavenging, which helps to increase the enthalpy of the turbine at low engine speed cannot be applied and thus leads to a reduction in low-end torque. Similarly, enrichment to keep the exhaust temperature sustainable in the exhaust tract components cannot be applied any more. The proposed study aims to provide a solution to keep the low end torque while maintaining lambda at 1.
2017-09-04
Technical Paper
2017-24-0155
Marc Sens, Michael Guenther, Matthias Hunger, Jan Mueller, Sascha Nicklitzsch, Ulrich Walther, Steffen Zwahr
Abstract The combination of geometrically variable compression (VCR) and early intake valve closure (EIVC) proved to offer high potential for increasing efficiency of gasoline engines. While early intake valve closure reduces pumping losses, it is detrimental to combustion quality and residual gas tolerance due to a loss of temperature and turbulence. Large geometric compression ratio at part load compensates for the negative temperature effect of EIVC with further improving efficiency. By optimizing the stroke/bore ratio, the reduction in valve cross section at part load can result in greater charge motion and therefore in turbulence. Turbocharging means the basis to enable an increase in stroke/bore ratio, called β in the following, because the drawbacks at full load resulting from smaller valves can be only compensated by additional boosting pressure level.
2017-09-04
Technical Paper
2017-24-0130
Antonio Paolo Carlucci, Marco Benegiamo, Sergio Camporeale, Daniela Ingrosso
Abstract 1 Nowadays, In-Cylinder Pressure Sensors (ICPS) have become a mainstream technology that promises to change the way the engine control is performed. Among all the possible applications, the prediction of raw (engine-out) NOX emissions would allow to eliminate the NOX sensor currently used to manage the after-treatment systems. In the current study, a semi-physical model already existing in literature for the prediction of engine-out nitric oxide emissions based on in-cylinder pressure measurement has been improved; in particular, the main focus has been to improve nitric oxide prediction accuracy when injection timing is varied. The main modification introduced in the model lies in taking into account the turbulence induced by fuel spray and enhanced by in-cylinder bulk motion.
2017-09-04
Technical Paper
2017-24-0125
Angelo Algieri, Pietropaolo Morrone, Jessica Settino, Teresa Castiglione, Sergio Bova
Abstract The aim of the present work is to analyse and compare the energetic performances and the emissions conversion capability of active and passive aftertreatment systems for lean burn engines. To this purpose, a computational one-dimensional transient model has been developed and validated. The code permits to assess the heat exchange between the solid and the exhaust gas, to evaluate the conversion of the main engine pollutants, and to estimate the energy effectiveness. The response of the systems to variations in engine operating conditions have been investigated considering standard emission test cycles. The analysis highlighted that the active flow control tends to increase the thermal inertia of the apparatus and then it appears more suitable to maintain higher temperature level and to guarantee higher pollutants conversion at low engine loads after long full load operation.
2017-09-04
Technical Paper
2017-24-0131
Sergio Mario Camporeale, Patrizia D. Ciliberti, Antonio Carlucci, Daniela Ingrosso
Abstract The incoming RDE regulation and the on-board diagnostics -OBD- pushes the research activity towards the set-up of a more and more efficient after treatment system. Nowadays, the most common after treatment system for NOx reduction is the selective catalytic reduction -SCR- . This system requires as an input the value of engine out NOx emission -raw- in order to control the Urea dosing strategy. In this work, an already existing grey box NOx raw emission model based on in-cylinder pressure signal (ICPS) is validated on two standard cycles: MNEDC and WLTC using an EU6 engine at the test bench. The overall results show a maximum relative error of the integrated cumulative value of 12.8% and 17.4% for MNEDC and WLTC respectively. In particular, the instantaneous value of relative error is included in the range of ± 10% in the steady state conditions while during transient conditions is less than 20% mainly.
2017-09-04
Technical Paper
2017-24-0136
Kurtis James Irwin, Roy Douglas, Jonathan Stewart, Andrew Pedlow, Rose Mary Stalker, Andrew Woods
Abstract With emission legislations becoming ever more stringent there is an increased pressure on the after-treatment systems, and more specifically the three-way catalysts. With recent developments in emission legislations, there is requirement for more complex after-treatment systems and understanding of the aging process. With future legislation introducing independent inspection of emissions at any time under real world driving conditions throughout a vehicle life cycle this is going to increase the focus on understanding catalyst behavior during any likely conditions throughout its lifetime and not just at the beginning and end. In recent years it has become a popular approach to use accelerated aging of the automotive catalysts for the development of new catalytic formulations and for homologation of new vehicle emissions.
2017-09-04
Technical Paper
2017-24-0137
Zhen Zhang, Luigi del Re, Richard Fuerhapter
Abstract During transients, engines tend to produce substantially higher peak emissions like soot - the main fraction of particular matter (PM) - which are the longer the more important as the steady state emissions are better controlled. While Diesel particulate filters are normally able to block them, preventing their occurrence would of course be more important. In order to achieve this goal, however, they must be measurable. While for most emissions commercial sensors of sufficient speed and performance are available, the same is not true for PMs, especially for production engines. Against this background, in the last years the possible use of a full stream 50Hz sensor based on Laser Induced Incandescence (LII) was investigated, and the results were very encouraging, showing that the sensor could recognize transient changes undetected by conventional measurement systems (like the AVL Opacimeter) but confirmed by the analysis of combustion.
2017-09-04
Technical Paper
2017-24-0163
Apostolos Pesiridis, Angelo Saccomanno, Raffaele Tuccillo, Alfredo Capobianco
Abstract The modern automotive industry is under strict regulations to reduce emissions to comply with the Kyoto Protocol, a universally acknowledged treaty aiming at reducing exhaust gas emissions. In order to achieve the required future emission reduction targets, further developments on gasoline engines are required. One of the main methods to achieve this goal is the application of engine downsizing. Turbocharging is a cost-effective method of downsizing an engine whilst reducing exhaust gas emissions, reducing fuel consumption and maintaining prior performance outputs. For these reasons, the turbocharging is becoming the most widely adopted technology in the automotive markets. In 2012, 32% of passenger and commercial vehicles sold had a turbocharger installed, and is predicted to be 40% of 2017 [1]. Even if the engine turbocharging is a widespread technology, there are still drawbacks present in current turbocharging systems.
2017-09-04
Technical Paper
2017-24-0167
Enrico Mattarelli, Carlo Rinaldini, Tommaso Savioli, Giuseppe Cantore, Alok Warey, Michael Potter, Venkatesh Gopalakrishnan, Sandro Balestrino
Abstract This work reports a CFD study on a 2-stroke (2-S) opposed piston high speed direct injection (HSDI) Diesel engine. The engine main features (bore, stroke, port timings, et cetera) are defined in a previous stage of the project, while the current analysis is focused on the assembly made up of scavenge ports, manifold and cylinder. The first step of the study consists in the construction of a parametric mesh on a simplified geometry. Two geometric parameters and three different operating conditions are considered. A CFD-3D simulation by using a customized version of the KIVA-4 code is performed on a set of 243 different cases, sweeping all the most interesting combinations of geometric parameters and operating conditions. The post-processing of this huge amount of data allow us to define the most effective geometric configuration, named baseline.
2017-09-04
Technical Paper
2017-24-0173
Jean-Charles Dabadie, Antonio Sciarretta, Gregory Font, Fabrice Le Berr
Abstract Due to more and more complex powertrain architectures and the necessity to optimize them on the whole driving conditions, simulation tools are becoming indisputable for car manufacturers and suppliers. Indeed, simulation is at the basis of any algorithm aimed at finding the best compromise between fuel consumption, emissions, drivability, and performance during the conception phase. For hybrid vehicles, the energy management strategy is a key driver to ensure the best fuel consumption and thus has to be optimized carefully as well. In this regard, the coupling of an offline hybrid strategy optimizer (called HOT) based on Pontryagin’s minimum principle (PMP) and an online equivalent-consumption-minimization strategy (ECMS) generator is presented. Additionally, methods to estimate the efficiency maps and other overall characteristics of the main powertrain components (thermal engine, electric motor(s), and battery) from a few design parameters are shown.
2017-09-04
Technical Paper
2017-24-0128
Lauretta Rubino, Jan Piotr Oles, Antonino La Rocca
Abstract Environmental authorities such as EPA, VCA have enforced stringent emissions legislation governing air pollutants released into the atmosphere. Of particular interest is the challenge introduced by the limit on particulate number (PN) counting (#/km) and real driving emissions (RDE) testing; with new emissions legislation being shortly introduced for the gasoline direct injection (GDI) engines, gasoline particulate filters (GPF) are considered the most immediate solution. While engine calibration and testing over the Worldwide harmonized Light vehicles Test Cycle (WLTC) allow for the limits to be met, real driving emission and cold start constitute a real challenge. The present work focuses on an experimental durability study on road under real world driving conditions. Two sets of experiments were carried out. The first study analyzed a gasoline particulate filter (GPF) (2.4 liter, diameter 5.2” round) installed in the underfloor (UF) position and driven up to 200k km.
2017-09-04
Technical Paper
2017-24-0033
Priyanka Dnyaneshwar Jadhav, J M Mallikarjuna
Abstract Future stringent emission norms are impelling researchers to look for new emission control techniques. Today, gasoline direct injection (GDI) engines are becoming more popular because of high potential to reduce exhaust emissions over a wide operating load range, unlike conventional port fuel injection (PFI) engines. Also, turbocharged GDI engines allow engine downsizing with a certain restriction on compression ratio (CR) due to knocking tendency, thereby limiting the fuel economy. However, use of exhaust gas recirculation (EGR) delays combustion and lowers the knocking tendency which will aid in improving the fuel economy. Therefore, this study is aimed to evaluate the effect of EGR rate on the performance and emission characteristics of a two-liter turbocharged four-stroke GDI engine by computational fluid dynamics (CFD) analysis. For the analysis, the CR of 9.3 and the engine speed of 1000 rev/min., are selected.
2017-09-04
Technical Paper
2017-24-0070
Stefano D'Ambrosio, Daniele Iemmolo, Alessandro Mancarella, Nicolò Salamone, Roberto Vitolo, Gilles Hardy
Abstract A precise estimation of the recirculated exhaust gas rate and oxygen concentration as well as a predictive evaluation of the possible EGR unbalance among cylinders are of paramount importance, especially if non-conventional combustion modes, which require high EGR flow-rates, are implemented. In the present paper, starting from the equation related to convergent nozzles, the EGR mass flow-rate is modeled considering the pressure and the temperature upstream of the EGR control valve, as well as the pressure downstream of it. The restricted flow-area at the valve-seat passage and the discharge coefficient are carefully assessed as functions of the valve lift. Other models were fitted using parameters describing the engine working conditions as inputs, following a semi-physical and a purely statistical approach. The resulting models are then applied to estimate EGR rates to both conventional and non-conventional combustion conditions.
2017-09-04
Technical Paper
2017-24-0018
Nikiforos Zacharof, Georgios Fontaras, Theodoros Grigoratos, Biagio Ciuffo, Dimitrios Savvidis, Oscar Delgado, J. Felipe Rodriguez
Abstract Heavy-duty vehicles (HDVs) account for some 5% of the EU’s total greenhouse gas emissions. They present a variety of possible configurations that are deployed depending on the intended use. This variety makes the quantification of their CO2 emissions and fuel consumption difficult. For this reason, the European Commission has adopted a simulation-based approach for the certification of CO2 emissions and fuel consumption of HDVs in Europe; the VECTO simulation software has been developed as the official tool for the purpose. The current study investigates the impact of various technologies on the CO2 emissions of European trucks through vehicle simulations performed in VECTO. The chosen vehicles represent average 2015 vehicles and comprised of two rigid trucks (Class 2 and 4) and a tractor-trailer (Class 5), which were simulated under their reference configurations and official driving cycles.
2017-09-04
Journal Article
2017-24-0041
Daniele Piazzullo, Michela Costa, Luigi Allocca, Alessandro Montanaro, Vittorio ROCCO
Abstract During gasoline direct injection (GDI) in spark ignition engines, droplets may hit piston or liner surfaces and be rebounded or deposit in the liquid phase as wallfilm. This may determine slower secondary atomization and local enrichments of the mixture, hence be the reason of increased unburned hydrocarbons and particulate matter emissions at the exhaust. Complex phenomena indeed characterize the in-cylinder turbulent multi-phase system, where heat transfer involves the gaseous mixture (made of air and gasoline vapor), the liquid phase (droplets not yet evaporated and wallfilm) and the solid walls. A reliable 3D CFD modelling of the in-cylinder processes, therefore, necessarily requires also the correct simulation of the cooling effect due to the subtraction of the latent heat of vaporization of gasoline needed for secondary evaporation in the zone where droplets hit the wall. The related conductive heat transfer within the solid is to be taken into account.
2017-09-04
Journal Article
2017-24-0045
Blane Scott, Christopher Willman, Ben Williams, Paul Ewart, Richard Stone, David Richardson
Abstract In-cylinder temperature measurements are vital for the validation of gasoline engine modelling and useful in their own right for explaining differences in engine performance. The underlying chemical reactions in combustion are highly sensitive to temperature and affect emissions of both NOx and particulate matter. The two techniques described here are complementary, and can be used for insights into the quality of mixture preparation by measurement of the in-cylinder temperature distribution during the compression stroke. The influence of fuel composition on in-cylinder mixture temperatures can also be resolved. Laser Induced Grating Spectroscopy (LIGS) provides point temperature measurements with a pressure dependent precision in the range 0.1 to 1.0 % when the gas composition is well characterized and homogeneous; as the pressure increases the precision improves.
2017-09-04
Journal Article
2017-24-0043
Thomas Kammermann, Jann Koch, Yuri M. Wright, Patrik Soltic, Konstantinos Boulouchos
Abstract The interaction of turbulent premixed methane combustion with the surrounding flow field can be studied using optically accessible test rigs such as a rapid compression expansion machine (RCEM). The high flexibility offered by such a test rig allows its operation at various thermochemical conditions at ignition. However, limitations inherent to such test rigs due to the absence of an intake stroke do not allow turbulence production as found in IC-engines. Hence, means to introduce turbulence need to be implemented and the relevant turbulence quantities have to be identified in order to enable comparability with engine relevant conditions. A dedicated high-pressure direct injection of air at the beginning of the compression phase is considered as a measure to generate adjustable turbulence intensities at spark timing and during the early flame propagation.
2017-09-04
Journal Article
2017-24-0057
Roberto Finesso, Omar Marello, Ezio Spessa, Yixin Yang, Gilles Hardy
Abstract A model-based approach to control BMEP (Brake Mean Effective Pressure) and NOx emissions has been developed and assessed on a FPT F1C 3.0L Euro VI diesel engine for heavy-duty applications. The controller is based on a zero-dimensional real-time combustion model, which is capable of simulating the HRR (heat release rate), in-cylinder pressure, BMEP and NOx engine-out levels. The real-time combustion model has been realized by integrating and improving previously developed simulation tools. A new discretization scheme has been developed for the model equations, in order to reduce the accuracy loss when the computational step is increased. This has allowed the required computational time to be reduced to a great extent.
Viewing 181 to 210 of 33425