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Viewing 1 to 30 of 2292
2015-09-06
Technical Paper
2015-24-2392
Vincenzo De Bellis, Luigi Teodosio, Daniela Siano, Fabrizio Minarelli, Diego Cacciatore
In this paper, a high performance V12 spark-ignition engine is experimentally investigated at test-bench in order to fully characterize its behavior in terms of both average and cycle-by-cycle performance parameters, for different operating conditions. In particular, for each considered point, a spark advance sweep is actuated, starting from a knock-free calibration, up to intense knock operation. Trains of 300 consecutive pressure cycles are acquired for each of the 12 cylinders, together with the main overall engine performance, including air flow, fuel flow, torque, pollutant emissions, and fuel consumption. Acquired data are statistically analyzed to derive the distributions of main indicated parameters (combustion phasing and duration, Indicated Mean Effective Pressure - IMEP, etc.) in order to find proper correlation with averaged quantities, collecting the findings of all the considered operating points and all the cylinders.
2015-09-06
Technical Paper
2015-24-2452
Benedikt Heuser, Sebastian Ahling, Florian Kremer, Stefan Pischinger, Hans Rohs, Bastian Holderbaum, Thomas Korfer
An experimental study has been carried out on dual-fuel operation with a Diesel engine for passenger car application. For these investigations, two very common fuels were chosen: For port fuel injection, the fuel used was gasoline (RON95, E10), for direct injection it was EN590 Diesel fuel. The experiments have been carried out almost in the whole engine load range from low part load at an indicated mean effective pressure (IMEP) of 0.43 MPa up to full load operation at an IMEP of 2.8 MPa. The engine speed was varied from 1500 rpm up to 4000 rpm. Within the relevant engine part load range, emissions of nitric oxides (NOx) were kept below the EU6 level at engine-out. At low part load, emissions of hydrocarbons (HC) and carbon monoxide (CO) as well as combustion stability are challenging in dual-fuel operation. Thus, the share of gasoline was limited to 60% m/m.
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
2015-24-2473
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
2015-24-2475
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
2015-24-2449
Mark Aaron Hoffman, Zoran Filipi
The limited operational range of Homogeneous Charge Compression Ignition engines is influenced by combustion chamber deposit accumulation and burn-off. Previous works have investigated in-situ combustion chamber deposit thermal properties with the end goal of replicating their increased temperature swing during compression and operability range shift in a manner which is independent of driving cycle. Combustion chamber deposit thermal diffusivity was found to differ depending on the location of deposit accumulation within the combustion chamber. These material property differences have been attributed to the spatially dependent interaction of deposits with the cylinder charge. This work establishes the methodology for determining the impact of directly injected gasoline on in-situ combustion chamber deposit thermal diffusivity.
2015-09-06
Journal Article
2015-24-2393
Fabio Bozza, Vincenzo De Bellis, Fabrizio Minarelli, Diego Cacciatore
The results of the experimental analyses described in the Part 1 of the paper, are here employed to build up an innovative numerical approach for the 1D modeling of combustion and knock of a high performance 12-cylinders spark-ignition engine. The whole engine is schematized in detail in a 1D framework simulation, developed in the GT-PowerTM environment. Proper “in-house developed” sub-models are used to describe the combustion process, turbulence phenomenon and the knock occurrence. In particular, the knock onset is evaluated by a TRF chemical kinetic scheme, coupled to the combustion model and able to detect the presence of auto-ignition reactions in the end-gas zone. A refined in-cylinder heat transfer model is adopted, based on a modified Woschni correlation. Wall temperature distributions are computed based on a proper specification of the heat transfer coefficients of the cooling water and lubricant oil.
2015-04-22
Event
This session focuses on abnormal SI combustion processes including spark knock and preignition. Papers cover both 4-stroke and 2-stroke engines characterized by 1) ignition by an external energy source that serves to control combustion phasing, and 2) a combustion rate that is limited by flame propagation. Part 2 of 2: Low-Speed Preignition
2015-04-22
Event
This session focuses on abnormal SI combustion processes including spark knock and preignition. Papers cover both 4-stroke and 2-stroke engines characterized by 1) ignition by an external energy source that serves to control combustion phasing, and 2) a combustion rate that is limited by flame propagation. Part 1 of 2: Knock
2015-04-22
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.
2015-04-22
WIP Standard
J285
This SAE recommended practice provided standard dimensions for liquid fuel dispenser nozzle spouts and a system for differentiating between nozzels that dispense liquid fuel into vehicles with Spark Ignition (SI) Engines and compression Ignition (CI) Engines for land vehicles. Current legal definitions only distinguish between "UNLEADED Fuel" and "All Other Types of Fuel." These definitions are no longer valid. This document establishes a new set of definitions that have practical application to current automobile liquid fuel inlets and liquid fuel dispenser nozzle spouts.
2015-04-14
Technical Paper
2015-01-1011
Kazutake Ogyu, Toyoki Ogasawara, Yuichi Nagatsu, Yuya Yamamoto, Tatsuhiro Higuchi, Kazushige Ohno
Abstract The Particle Number (PN) emission limit is implemented for Direct Injection (DI) gasoline from EU6 regulation in European region. The wall-flow type ceramic filter technology is an essential component for Diesel PN emission control, and will be one potential solution to be investigated for the future Gasoline DI PN emission control demand. Especially the requirement of lower pressure loss with smaller filter volume is very strong for the filter substrate for Gasoline DI compared to DPF, not to lose better fuel economy benefit of Gasoline DI engine. Re-crystallized SiC (R-SiC) has high strength as its own property, and enable for Gasoline Particulate Filter (GPF) design to make the wall thickness thinner and the porosity higher compared to the other ceramic materials.
2015-04-14
Technical Paper
2015-01-1076
Tak W. Chan
Abstract This study reported black carbon (BC) mass and solid particle number emissions from a gasoline direct injection (GDI) vehicle and a port fuel injection (PFI) vehicle on splash blended E10 and iB16 fuels over the FTP-75 and US06 drive cycles at standard and cold ambient temperatures. For the FTP-75 drive cycle, the GDI vehicle had lower solid particle number and BC mass emissions from E10 (5.1×1012 particles/mile; 4.2 mg/mile) and iB16 (5.2×1012 particles/mile; 3.9 mg/mile) compared to E0 (7.2×1012 particles/mile; 7.0 mg/mi). Most of the reductions were attributed to the statistically significant reductions during the phases 1 and 2 of the FTP-75 drive cycle. iB16 was also observed to have statistically significant reduction on BC emissions when compared to E0 at cold ambient temperature but E10 did not show such BC reduction. For the PFI vehicle, most of the solid particle number and BC mass emissions were emitted primarily during phase 1 of the FTP-75 drive cycle.
2015-04-14
Technical Paper
2015-01-1082
Xin Wang, Yunshan Ge, Linlin Liu, Huiming Gong
Abstract As a probable solution to both energy and environmental crisis, methanol and methanol gasoline have been used as gasoline surrogates in several provinces of China. Most recently, the Ministry of Environmental Protection of China is drafting a special emission standard for methanol-fueled light-duty vehicles. Given the scarcity of available data, this paper evaluated regulated emissions, carbonyl compounds and particulate matter from a China-5 certificated gasoline/methanol dual-fuel vehicle over New European Driving Cycle (NEDC). The results elucidated that in context with gasoline mode, CO emitted in methanol mode decreased 11.2%, while no evident changes of THC and NOx emissions were noticed with different fueling regimes. The total carbonyls and formaldehyde have increased by 39.5% and 19.8% respectively after switching from gasoline to methanol. A remarkable decrease of 65.6% in particulate matter was observed in methanol mode.
2015-04-14
Technical Paper
2015-01-1242
Hao Yuan, Tien Mun Foong, Zhongyuan Chen, Yi Yang, Michael Brear, Thomas Leone, James E. Anderson
Abstract This paper presents a numerical study of trace knocking combustion of ethanol/gasoline blends in a modern, single cylinder SI engine. Results are compared to experimental data from a prior, published work [1]. The engine is modeled using GT-Power and a two-zone combustion model containing detailed kinetic models. The two zone model uses a gasoline surrogate model [2] combined with a sub-model for nitric oxide (NO) [3] to simulate end-gas autoignition. Upstream, pre-vaporized fuel injection (UFI) and direct injection (DI) are modeled and compared to characterize ethanol's low autoignition reactivity and high charge cooling effects. Three ethanol/gasoline blends are studied: E0, E20, and E50. The modeled and experimental results demonstrate some systematic differences in the spark timing for trace knock across all three fuels, but the relative trends with engine load and ethanol content are consistent. Possible reasons causing the differences are discussed.
2015-04-14
Technical Paper
2015-01-0762
Mitsuru Kowada, Isao Azumagakito, Tetsuya Nagai, Nobuyuki Iwai, Ryoji Hiraoka
Abstract Attempts were made to measure knocking phenomenon by an optical method, which is free from influences of mechanical noises and is allowing an easy installation to an engine. Using a newly developed high durability optical probe, the light intensity of hydroxyl radical component, which is diffracted from the emitted light from combustion, was measured. The intensity of this emission component was measured at each crank angle and the maximum intensity in a cycle was identified. After that, the angular range in which the measured intensity exceeded 85% of this maximum intensity was defined as “CA85”. When a knocking was purposely induced by changing the conditions of the engine operation, there appeared the engine cycles that included CA85 less than a crank angle of 4 degrees. The frequency of occurrence of CA85 equal to or less than 4 degrees within a predetermined number of engine cycles, which can be interpreted as a knocking occurrence ratio, was denoted as “CA85-4”.
2015-04-14
Technical Paper
2015-01-0924
Joseph Camm, Richard Stone, Martin Davy, David Richardson
Abstract A model for the evaporation of a multi-component fuel droplet is presented that takes account of temperature dependent fuel and vapour properties, evolving droplet internal temperature distribution and composition, and enhancement to heat and mass transfer due to droplet motion. The effect on the internal droplet mixing of non-ideal fluid diffusion is accounted for. Activity coefficients for vapour-liquid equilibrium and diffusion coefficients are determined using the UNIFAC method. Both well-mixed droplet evaporation (assuming infinite liquid mass diffusivity) and liquid diffusion-controlled droplet evaporation (iteratively solving the multi-component diffusion equation) have been considered.
2015-04-14
Technical Paper
2015-01-0752
Zhi Wang, Yunliang Qi, Hui Liu, Yan Long, Jian-Xin Wang
Abstract Occurrence of sporadic super-knock is the main obstacle to the development of advanced gasoline engines. One of the possible inducements of super-knock, agglomerated soot particle induced pre-ignition, was studied for high boosted gasoline direct injection (GDI) engines. The correlation between soot emissions and super-knock frequency was investigated in a four-cylinder gasoline direct injection production engine. The test results indicate that higher in-cylinder soot emission correlate with more pre-ignition and super-knock cycles in a GDI production engine. To study the soot/carbon particles trigger super-knock, a single-cylinder research engine for super-knock study was developed. The carbon particles with different temperatures and sizes were introduced into the combustion chamber to trigger pre-ignition and super-knock.
2015-04-14
Technical Paper
2015-01-0750
Shinrak Park, Tetsuji Furukawa
Abstract Downsizing or higher compression ratio of SI engines is an appropriate way to achieve considerable improvements of part load fuel efficiency. As the compression ratio directly impacts the engine cycle thermal efficiency, it is important to increase the compression ratio in order to reduce the specific fuel consumption. However, when operating a highly boosted / downsized SI engine at full load, the actual combustion process deviates strongly from the ideal Otto cycle due to the increased effective loads requiring ignition timing delay to suppress abnormal combustion phenomena such as engine knocking. This means that for an optimal design of an SI engine between balances must be found between part load and full load operation. If the knocking characteristic can be accurately predicted beforehand when designing the combustion chamber, a reduction of design time and /or an increase in development efficiency would be possible.
2015-04-14
Technical Paper
2015-01-0827
Yan Zhang, Macklini Dalla Nora, Hua Zhao
Abstract Controlled Auto Ignition (CAI), also known as Homogeneous Charge Compression Ignition (HCCI), is one of the most promising combustion technologies to reduce the fuel consumption and NOx emissions. Most research on CAI/HCCI combustion operations have been carried out in 4-stroke gasoline engines, despite it was originally employed to improve the part-load combustion and emission in the two-stroke gasoline engine. However, conventional ported two-stroke engines suffer from durability and high emissions. In order to take advantage of the high power density of the two-stroke cycle operation and avoid the difficulties of the ported engine, systematic research and development works have been carried out on the two-stroke cycle operation in a 4-valves gasoline engine. CAI combustion was achieved over a large range of operating conditions when the relative air/fuel ratio (lambda) was kept at one as measured by an exhaust lambda sensor.
2015-04-14
Technical Paper
2015-01-0764
Seokwon Cho, Namho Kim, Jongwon Chung, Kyoungdoug Min
Abstract Ethanol is becoming more popular as a fuel component for spark-ignited engines. Ethanol can be used either as an octane enhancer of low RON gasoline or splash-blended with gasoline if a single injector is used for fuel injection. If two separate injectors are used, it is possible to inject gasoline and ethanol separately and the addition of ethanol can be varied on demand. In this study, the effect of the ethanol injection strategy on knock suppression was observed using a single cylinder engine equipped with two port fuel injectors dedicated to each side of the intake port and one direct injector. If the fuel is injected to only one side of the intake port, it is possible to form a stratified charge. The experiment was conducted under a compression ratio of 12.2 for various injection strategies.
2015-04-14
Technical Paper
2015-01-0760
Sabino Luisi, Vittorio Doria, Andrea Stroppiana, Federico Millo, Mohsen Mirzaeian
Abstract The application of Miller cycle through Late Intake Valve Closure (LIVC) or Early Intake Valve Closure (EIVC) for knock mitigation at high load on a turbocharged downsized spark ignition engine was experimentally investigated. By reducing the effective compression ratio due to a shorter compression stroke and hence achieving lower charge temperatures inside the cylinder, significant mitigation of knock tendency could be obtained. As a consequence, the spark advance retard could be substantially decreased and the enrichment of the mixture could significantly be reduced, thus obtaining impressive efficiency improvements. In this research, both EIVC and LIVC strategies have been examined aiming to achieve possible improvements for knock mitigation and after some preliminary investigations confirmed LIVC being more effective than EIVC for this goal, the latter was discarded and the research activities were focused on LIVC only.
2015-04-14
Technical Paper
2015-01-0848
Silvana Di Iorio, Paolo Sementa, Bianca Maria Vaglieco
Abstract The aim of the paper is the comparison of the performance, gaseous and particle emissions from different injection configurations and fuels. The engine was operated in port fuel injection (PFI), direct injection (DI) and dual fuel (DF). For DF, ethanol DI-gasoline PFI and gasoline DI-gasoline PFI strategies were performed to discern the effect of injection strategy from the effect of the fuel. The experimental activity was carried out in a small displacement single cylinder engine, representative of 2-3 wheel vehicle engines or of 3-4 cylinder small displacement automotive engines. It was equipped with a prototype gasoline direct injection (GDI) head. The tests were carried out at 3000 rpm, 4000 rpm and 5000 rpm full load. The investigated engine operating conditions are representative of the homologation urban driving cycle. The gaseous and particle emissions were measured at the exhaust by means of a gas analyzer and a smoke meter.
2015-04-14
Technical Paper
2015-01-0833
Buyu Wang, Zhi Wang, Shi-Jin Shuai, Jian-Xin Wang
Abstract A study of Multiple Premixed Compression Ignition (MPCI) with mixtures of gasoline and diesel is performed on a light-duty single cylinder diesel engine. The engine is operated at a speed of 1600rpm with the same fuel mass per cycle. By keeping the same intake pressure and EGR ratio, the influence of different blending ratios in gasoline and diesel mixtures (90vol%, 80vol% and 70vol% gasoline) is investigated. Combustion and emission characteristics are compared by sweeping the first (−95 ∼ −35deg ATDC) and the second injection timing (−1 ∼ 9deg ATDC) with an injection split ratio of 80/20 and an injection pressure of 80MPa. The results show that compared with diesel combustion, the gasoline and diesel mixtures can reduce NOx and soot emissions simultaneously while maintaining or achieving even higher indicated thermal efficiency, but the HC and CO emissions are high for the mixtures.
2015-04-14
Technical Paper
2015-01-0832
Christopher Kolodziej, Janardhan Kodavasal, Stephen Ciatti, Sibendu Som, Neeraj Shidore, Jeremy Delhom
Abstract For several years there has been a great deal of effort made in researching ways to run a compression ignition engine with simultaneously high efficiency and low emissions. Recently much of this focus has been dedicated to using gasoline-like fuels that are more volatile and less reactive than conventional diesel fuel to allow the combustion to be more premixed. One of the key challenges to using fuels with such properties in a compression ignition engine is stable engine operation at low loads. This paper provides an analysis of how stable gasoline compression ignition (GCI) engine operation was achieved down to idle speed and load on a multi-cylinder compression ignition engine using only 87 anti-knock index (AKI) gasoline. The variables explored to extend stable engine operation to idle included: uncooled exhaust gas recirculation (EGR), injection timing, injection pressure, and injector nozzle geometry.
2015-04-14
Technical Paper
2015-01-0767
Richard Stradling, David Rickeard, Heather Hamje, John Williams, Peter Zemroch
Abstract The performance aspect of gasoline combustion has traditionally been measured using Research Octane Number (RON) and Motor Octane Number (MON) which describe antiknock performance under different conditions. Recent literature suggests that MON is less important than RON in modern cars and a relaxation in the MON specification could improve vehicle performance, while also helping refiners in the production of gasoline. At the same time, for the same octane number change, increasing RON appears to provide more benefit to engine power and acceleration than reducing MON. It has also been suggested that there could be fuel efficiency benefits (on a tank to wheels basis) for specially adapted engines, for example, operating at higher compression ratio, on very high RON (100+). Other workers have advocated the use of an octane index (OI) which incorporates both RON and MON to give an indication of octane quality.
2015-04-14
Technical Paper
2015-01-0942
Vikram Singh, Anshul Koli
Abstract This research presents the simulation of the jet behavior of gasoline ethanol blends in a quiescent chamber using the Lattice Boltzmann method. The fuel is taken as different mixtures of gasoline and ethanol, and the properties, such as density, viscosity and surface tension, are varied accordingly in the Lattice Boltzmann model. The variations in jet structure and instabilities are modeled according to the velocity of fuel injection, the composition of the gasoline-ethanol blend and the property of the surrounding mixture. The model implemented for the interaction of the two fluids; air and fuel, is the Shan Chen model. The accuracy of the model is confirmed using a static drop test at different curvatures for the two fluids as well as observing the evolution of merging droplets. This is the first time that the study of different fuels in done using the Shan Chen model.
2015-04-14
Journal Article
2015-01-0763
Gina M. Chupka, Earl Christensen, Lisa Fouts, Teresa L. Alleman, Matthew A. Ratcliff, Robert L. McCormick
Abstract The objective of this work was to measure knock resistance metrics for ethanol-hydrocarbon blends with a primary focus on development of methods to measure the heat of vaporization (HOV). Blends of ethanol at 10 to 50 volume percent were prepared with three gasoline blendstocks and a natural gasoline. Performance properties and composition of the blendstocks and blends were measured, including research octane number (RON), motor octane number (MON), net heating value, density, distillation curve, and vapor pressure. RON increases upon blending ethanol but with diminishing returns above about 30 vol%. Above 30% to 40% ethanol the curves flatten and converge at a RON of about 103 to 105, even for the much lower RON NG blendstock. Octane sensitivity (S = RON - MON) also increases upon ethanol blending. Gasoline blendstocks with nearly identical S can show significantly different sensitivities when blended with ethanol.
2015-04-14
Journal Article
2015-01-0894
Michael D. Kass, Chris Janke, Timothy Theiss, James Baustian, Leslie Wolf, Wolf Koch
Abstract The compatibility of plastic materials used in fuel storage and dispensing applications was determined for a test fuel representing gasoline blended with 10% ethanol. Prior investigations were performed on gasoline fuels containing 25, 50 and 85% ethanol, but the knowledge gap existing from 0 to 25% ethanol precluded accurate compatibility assessment of low level blends, especially for the current E10 fuel (gasoline containing 10% ethanol) used in most filling stations, and the recently accepted E15 fuel blend (gasoline blended with up to15% ethanol). For the majority of the plastic materials evaluated in this study, the wet volume swell (which is the parameter most commonly used to assess compatibility) was higher for fuels containing 25% ethanol, while the volume swell accompanying E10 was much lower.
Viewing 1 to 30 of 2292

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