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2016-10-24
Event
Separate sub-sessions cover zero-dimensional, one-dimensional, and quasi-dimensional models for simulation of SI and CI engines with respect to: engine breathing, boosting, and acoustics; SI combustion and emissions; CI combustion and emissions; fundamentals of engine thermodynamics; numerical modeling of gas dynamics; thermal management; mechanical and lubrication systems; system level models for controls; system level models for vehicle fuel economy and emissions predictions.
2016-10-24
Event
This session focuses on both SI and CI combustion and mixture preparation during cold start and transient engine operation. Example topics include engine performance, emissions, control strategies and calibrations for cold start and transient operation impact on NOx, PM, HC, CO, and CO2 emissions; also including the impact of variable valve timing, spark, and turbocharger controls.
2016-10-24
Event
Classical SI combustion characterized by ignition by an external energy source that serves to control combustion phasing and a combustion rate that is determined by flame propagation. The scope of topics includes efficiency, emissions, knock, preignition, direct injection, ignition strategies, and fuel / additive effects. Papers describing experimental or applied simulation results are invited and will be placed in appropriate sub-sessions. Papers with an emphasis on the modeling aspects of combustion are encouraged to be submitted into FFL110 or FFL120 modeling sessions.
2016-10-24
Event
Mixed modes with both flame propagation and slow auto ignition. Distinct from SI knock: autoignition is desired and will not ruin the engine. Papers describing experiments and test data, simulation results focused on applications, fuel/additive effects, and SACI mode change are invited and will be placed in appropriate sub-sessions. Papers with an emphasis on the modeling aspects of combustion are encouraged to be submitted into FFL110 or FFL120 modeling sessions.
2016-10-24
Event
Mixed mode with auto ignition but inhomogeneous charge. Injection-controlled but with EOI before SOC. Papers describing experiments and test data, simulation results focused on applications, fuel/additive effects, combustion control, and PPC injection strategies are invited and will be placed in appropriate sub-sessions. Papers with an emphasis on the modeling aspects of combustion are encouraged to be submitted into FFL110 or FFL120 modeling sessions.
2016-10-24
Event
This session focuses on fuel injection, combustion, controls, performance and emissions of SI engines fueled with gaseous fuels such as methane, natural gas (NG), biogas, producer gas, coke oven gas, hydrogen, or hydrogen-NG blends. Papers on Diesel-NG or diesel-hydrogen dual-fuel engines will also be accepted in this session.
2016-10-24
Event
This session covers the Power Cylinder: piston, piston rings, piston pins, and connecting rods. The papers include information on reducing friction and increasing fuel economy, improving durability by understanding wear, and decreasing oil consumption and blow-by.
2016-10-24
Event
This session covers topics regarding new CI and SI engines and components. This includes analytical, experimental, and computational studies covering hardware development as well as design and analysis techniques.
2016-04-12
Event
This session covers topics regarding new CI and SI engines and components. This includes analytical, experimental, and computational studies covering hardware development as well as design and analysis techniques.
2016-04-12
Event
This session covers topics regarding new CI and SI engines and components. This includes analytical, experimental, and computational studies covering hardware development as well as design and analysis techniques.
2016-04-05
Technical Paper
2016-01-0674
Macklini Dalla Nora, Thompson Lanzanova, Yan Zhang, Hua Zhao
With the introduction of fuel economy or CO2 emissions legislation in Europe and many countries, there has been extensive research on developing high efficiency gasoline engines by means of the downsizing technology. Engine downsizing is typically achieved by combining direct fuel injection, variable valve actuation, boosting technologies and improved quality fuels in four-stroke poppet valve engines. Under this approach the engine operation is shifted towards higher load regions where pumping and friction losses have a reduced effect, so improved efficiency is achieved with smaller displacement engines. However, to ensure the same full load performance of larger engines the charge density needs to be increased, which raises concerns about structural stresses and abnormal combustion at high in-cylinder pressures.
2016-04-05
Technical Paper
2016-01-0697
Francesco Catapano, Silvana Di Iorio, Ludovica Luise, Paolo Sementa, Bianca Maria Vaglieco
Even more attention was paid to the direct injection (DI) system in spark ignition (SI) engines. DI allows to achieve improved efficiency. Nevertheless, the less time for fuel evaporation and mixing with respect to PFI engines as well as the larger fuel impingement, results in larger HC and CO emissions as well as particle emissions. PFI SI engine are characterized by low exhaust emissions but at the same time by lower engine performance. In this paper was investigated the effect of the O2 addition on engine performance and emissions. The experimental investigation was carried out in a small single-cylinder, PFI SI four-stroke engine. The engine emissions were characterized by means of gaseous analyzers and a smokemeter. Particle size distribution function was measured in the size range from 5.6 to 560 nm by means of an Engine Exhaust Particle Sizer (EEPS). The investigation was carried out at different engine speeds.
2016-04-05
Technical Paper
2016-01-1014
Shyam K. Menon, Himakar Ganti, Chris Hagen
Natural gas is an attractive option for transportation applications in the United States due to its abundant availability and potential for reduced emissions. The scarcity of refueling resources imposes a barrier to widespread use of natural gas in internal combustion engines. A novel bi-modal engine under development is capable of operating in a compressor mode and provide refueling capabilities without any supplemental devices thus overcoming the infrastructure based limitations. As part of this development, a multi-cylinder production engine was acquired and its intake modified to allow for one cylinder to perform compression. This system was tested with accompanying plate heat exchangers that allow for cooling of the compressed gas.
2016-04-05
Technical Paper
2016-01-0758
Hui Liu, Zhi Wang, Yan Long, Shouzhi Xiang, Jianxin Wang
Particle number (PN) have already been a big issue for developing high efficiency internal combustion engine (ICE). In this study, controlled spark-assisted stratified compression ignition (SSCI) with moderate end-gas auto-ignition was used for reducing PN in a high compression ratio gasoline direct injection (GDI) engine. Under wide open throttle (WOT) and minimum spark advance for best torque (MBT) condition, high external cooled exhaust gas recirculation (EGR) was filled in the cylinder, while two-stage direct injection was used to form desired stoichiometric but stratified mixture. SSCI combustion mode exhibits two-stage heat release, where the first stage is associated with flame propagation induced by spark ignition and the second stage is the result of moderate end-gas auto-ignition without pressure oscillation at the middle or late stage of the combustion process.
2016-04-05
Technical Paper
2016-01-0710
Adrian Irimescu, Simona Silvia Merola, Cinzia Tornatore, Gerardo Valentino, Alberto Grimaldi, Eugenio Carugati, Stefano Silva
Within the context of generalized diversification of the energy mix, the use of alcohols as gasoline replacement is proposed as a viable option. In the quest for improving fuel economy and reduce the environmental impact of automotive engines, alternative control strategies for spark ignition engines (SI) such as lean operation and exhaust gas recirculation (EGR) are used on an ever wider scale. In order to improve the stability of these operating points, alternative ignition systems are currently investigated. Another trend that is more and more present in engine development is the extensive use of simulation software; therefore, there is a continuous drive to improve the predictive capabilities of numerical codes. Within this context, the present work reports on the use of a plasma assisted ignition (PAI) system in a direct injection (DI) SI engine under lean conditions and cooled EGR with gasoline and n-butanol fueling.
2016-04-05
Technical Paper
2016-01-0721
Andrew B. Mansfield, Elana Chapman, Kenneth Briscoe
The propensity for stochastic pre-ignition (SPI) of simulated gasoline mixtures was investigated at typical operating conditions using contemporary 2.0 L turbocharged engine. While frequency of SPI is often the sole observation in similar studies, peak pressures during SPI events were also analyzed in this work in order to provide a more complete and realistic picture of the behavior. The systematically formulated fuel combinations used here provided a distinct opportunity to elucidate specific fuel effects. In-cylinder pressure time history measurements made during a speed-load test sequence were used to determine both the frequency of SPI and the peak pressure during such events. Six fuels were tested with varying levels of aromatic content (15 - 35%) and two octane rating levels (~88 & 94 AKI). Significant SPI behaviors were observed, with SPI frequencies up to ~1 SPI event per 1,000 engine cycles and peak in-cylinder pressures up to ~200 bar.
2016-04-05
Technical Paper
2016-01-1011
Shui Yu, Qingyuan Tan, Mark Ives, Mengzhu Liu, Liguang Li, Xiang Chen, Ming Zheng
The development of present day spark ignition (SI) engines has imposed higher demands for its on-board ignition systems. Different spark voltage and current patterns are required for those SI engines to help initiate ignition and to improve the energy transfer efficiency from the system’s primary side to its secondary side. Proper design of the ignition system circuit is required to achieve certain spark performances, the lack of an arranged instructional document made it quite inconvenient for designers to develop a spark ignition system which can perform up to the required criteria. In this paper, the authors studied the relation between spark electric characteristics and different inductive spark ignition circuit parameters with the help of a simplified circuit model. The circuit model catches the principle behavior of the spark ignition system and uses a diode model to approximate the spark plug.
2016-04-05
Technical Paper
2016-01-0699
Jacob McKenzie, Wai K. Cheng
An ignition delay correlation encompassing the effects of temperature, pressure, residual gas, EGR, and lambda (on both the rich and lean sides) has been developed. The procedure uses the individual knocking cycle data from a boosted direct injection SI engine (GM LNF) operating at 1250 to 2000 rpm, 8-14 bar GIMEP, EGR of 0 to 12.5%, and lambda of 0.8 to 1.3 with a certification fuel (Haltermann 437, with RON=96.6 and MON=88.5). An algorithm has been devised to identify the knock point on individual pressure traces so that the large data set (of some thirty three thousand cycles) could be processed automatically. For lean and for rich operations, the role of the excess fuel, air, and recycled gas (which has excess air in the lean case, and hydrogen and carbon monoxide in the rich case) may be treated as effective diluents in the ignition delay expression.
2016-04-05
Technical Paper
2016-01-0704
Jacob McKenzie, Wai K. Cheng
Traditional analysis of the SI engine knocking process focuses on the auto-ignition process. This paper considers instead the combustion process after auto-ignition. The three classical modes of knock combustion are discussed in terms of the energy release rate and the size of the exothermic center. In the “flame” mode, acoustic expansion of the exothermic center is fast enough to prevent local pressure build up; normal flame propagation is initiated by the ignited region without development of acoustic wave. In the “knock” mode, the local pressure build-up sets up a pressure wave which excites the engine structural vibration, but the wave is not sufficient to ignite the end gas; normal flame propagation is again initiated by the ignited region. In the “detonation” mode, the end gas is ignited by the pressure wave to create a very fast Chapman Jouguet type denotation. For the “knock” mode, a knock intensity (KI) is defined as the pressure oscillation amplitude.
2016-04-05
Technical Paper
2016-01-0666
Guillaume Bourhis, Jean-Pascal Solari, Virginie Morel, Roland DAUPHIN
The efficiency of spark ignition engines is usually limited by the appearance of knock, which is linked to fuel octane number (RON). If running the engine at its optimal efficiency requests a high octane number at high load, a lower octane number is less necessary at low load. Aramco, along with its long term partner IFP Energies nouvelles, has been developing a synergistic fuel-engine system where the engine is fed by a fuel with an octane number adjusted in real time, as needed basis, while running at its optimal efficiency. Two major steps are identified to develop this ‘Octane on Demand’ concept: - First, characterize the octane requirement needed to run the engine at its optimal efficiency over the entire map; - Then, select the best fuel couple including a base fuel and an octane booster to fit this concept.
2016-04-05
Technical Paper
2016-01-0801
Dimitri Seboldt, David Lejsek, Marlene Wentsch, Marco Chiodi, Michael Bargende
The growing transport sector and the associated environmental pollution due to combustion engine emissions raise public awareness with respect to the development of economical and low-emission propulsion systems. In the scope of this problem the use of CNG as fuel for internal combustion engines appears to be even more as the right choice compared to the conventional liquid fuels. Especially, the direct injection of natural gas provides a strong potential to establish this environmentally friendly propulsion. But due to the fact that this technology is not ready for series production there is still major need for research on a suitable injection system and mixture formation. Despite the fuel's gaseous state and the lack of evaporation the mixture preparation is made worse by the low mass density. This property leads to an enhanced jet deflection by the in-cylinder flow which is for itself extremely spatial and time dependent.
2016-04-05
Technical Paper
2016-01-0483
Honglu Wang, Bogdan Nitu, Jaspal Sandhu, Lurun Zhong, Bruce K. Geist, William F. Resh
Valvetrain dynamics modeling and engine combustion modeling are often carried out independently. As a result, the interplay between these two physical responses may not be accurately assessed. The objective of this work is to understand the impact that robust valve timing simulations, implemented using a fully coupled valve train dynamics and engine performance model, have on engine performance prediction. The integrated simulation and detailed technical approach are discussed through the presentation of an example implementation. An I4 engine model is developed in which engine performance and valvetrain dynamics modeling are coupled. A benefit of this multi-physics approach is that it reduces reliance on empirically derived estimates of lash adjuster performance in favor of physical modeling and prediction of lash adjuster response.
2016-04-05
Technical Paper
2016-01-1018
Shan Wang, ZhenFeng Zhao, Shuanlu Zhang, Jinxiang Liu, Yuhang Liu
In this paper, a new method for the driving of hydraulic free piston engine (HFPE) is proposed. Hydraulic differential drive achieves the compression stroke automatically rather than special recovery system, which has a great influence on the engine dynamic performance. The purpose of this paper is to solve the key operation and control problems for HFPE to commix fuel with air. HFPE adopts two-stroke loop scavenging and semi-direct injection. Different scavenging pressures and injection angles result in different impacts on the mixture of fuel and air in the cylinder. This study analyzes the changes of the combustion heat release rate by simulation. The result shows that the gasoline back-flow and short circuit loss is minimum, and mixture of fuel and air is uniform , with the initial pressure of 0.13 Mpa and injection angle of 120°CA. Moreover, heat release of HFPE is enhanced, which complies with the requirements of the original design.
2016-04-05
Technical Paper
2016-01-0747
Vicente Bermudez, Raul Payri, J. Javier Lopez, Daniel Campos, Gilles Coma, Frederic Justet
Nowadays, 2-stroke CAI engines are under investigation in the context of direct injection gasoline engines as a solution to the CO2 future legislations. Since the main part of these investigations are centered on engine performance or some engine processes simulation, leaving aside particle number (PN) emission evaluation, this paper will focus on this last topic: particle emission analysis when using two different injectors, and a global comparison of PN emission of the present engine with its corresponding 4-stroke engine at three operating conditions keeping the same BMEP. This work has been performed in a single-cylinder gasoline engine with 0.3 l displacement, equipped with an air-assisted direct-injection fuel injection system. The equipment used in this study is a TSI-EEPS 3090 device for particle measurement and a DEKATI-FPS 4000 as a dilution system. Concerning the two injectors evaluated, significant differences in particle emission have been found.
2016-04-05
Technical Paper
2016-01-0696
Xiucheng Zhu, Lorenzo Sforza, Tejas Ranadive, anqi zhang, Seong-Young Lee, Jeffrey Naber, Tommaso Lucchini, Angelo Onorati, Muniappan Anbarasu, Yangbing Zeng
Fuel lean and exhaust gas dilution are known to increase the thermal efficiency and reduce the NOx emissions. In this study, experiments are performed to understand the effect of equivalence ratio on flame kernel formation and flame propagation around the spark plug for different low turbulent velocities. A series of experiments are carried out for propane-air mixtures to simulate engine-like conditions. For these experiments, the equivalence ratio of 0.7, 0.8, and 0.9 is tested with 20 percent mass-based exhaust gas recirculation (EGR). Turbulence is generated by a shrouded fan design in the vicinity of J-spark plug. A closed loop feedback control system is used for the fan to generate a consistent flow field. The flow profile is characterized by using Particle Image Velocimetry (PIV) technique. High-speed schlieren visualization is used for the spark formation and flame propagation.
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