Display:

Results

Viewing 61 to 90 of 22750
2015-04-14
Technical Paper
2015-01-1162
Frank Atzler, Michael Wegerer, Fabian Mehne, Stefan Rohrer, Christoph Rathgeber, Sebastian Fischer
Downsized engines and 48V electrification are important enablers for achieving future emission and CO2 targets. A perfect fit with an attractive benefit-cost level can be achieved by a holistic approach that goes beyond a simple implementation of individual solutions. Some aspects and results will be given in this publication. The overall propulsion efficiency advancement includes the optimization of the internal combustion engine, the manual transmission as well as the Continental’s 48V Eco Drive system. In combination with the electric motor, the internal combustion engine can be calibrated to work very efficiently and with improved transient response. A comfortable drivability even at low engine speeds can be realized by the improved low-end-torque performance thanks to the electrical engine assist and other propulsion measures.
2015-04-14
Technical Paper
2015-01-1264
Junseok Chang, Yoann Viollet, Abdullah Alzubail, Amir Faizal Naidu Abdul-Manan, Abdullah Al Arfaj
This paper explores the potential for reducing transport-related greenhouse gas (GHG) emissions by introducing high-efficiency spark-ignition engines with a dual-fuel injection system to customize octane of the fuels based on real-time engine requirements. Recent study [1] shows that 4-6% GHG emissions can be reduced by replacing 2/3 light duty vehicle fleet with high efficiency engines that are designed with higher compression ratio and boost levels. However, this can be only possible if premium gasoline fuel (Research Octane Number, RON=98 or 100) is readily available on a large scale to supply a fleet demand. From a refinery perspective, increasing the octane of the fuels to such high levels could potentially require significant and costly upgrades to the reforming and isomerization units as well as lower gasoline yield, and thus, this is not an economically attractive option for many of the refiners. In our study, we considered different strategy.
2015-04-14
Technical Paper
2015-01-1259
Tapio Pohjalainen, Martti Larmi
This study presents a novel crank mechanism which enables easy and fast compression ratio adjustment. The novel crank mechanism and piston travel is explained and highlighted. The basic idea is to have an eccentric crank pin. Compression ratio can be adjusted to best fit current load demand either optimizing fuel efficiency or engine power and torque. Adjustment is individual to each cylinder within 10 ms from max to min. Emphasis in this design is the reduction of CO2 emissions and thus the fuel consumption. Governing mechanical equations are presented and discussed in detail. This novel crank mechanism introduces two new governing design parameters, namely the eccentricity of the crank pin and the angle of eccentricity when cam angle is 0°. In this demonstration unit the gear ratio between the eccentric gear and control gear is set to 1.5. This will make the induction-compression cycle different to expansion-exhaust cycle.
2015-04-14
Technical Paper
2015-01-1025
Gordon J. Bartley
The drive to more fuel efficient vehicles is underway, with passenger car targets of 54.5 mpg fleet average by 2025. Improving engine efficiency means reducing losses such as the heat lost in the exhaust gases. But, reducing exhaust temperature makes it harder for emissions control catalysts to function because they require elevated temperatures to be active. Addressing this conundrum was the focus of the work performed. The primary objective of this work was to identify low temperature limiters for a variety of catalyst aftertreatment types. The ultimate goal is to reduce catalyst light-off temperatures, and the knowledge needed is an understanding of what prevents a catalyst from lighting off, why, and how it may be mitigated. Collectively these are referred to here as low temperature limiters to catalyst activity.
2015-04-14
Technical Paper
2015-01-1026
Padmanabha Reddy Ettireddy, Adam Kotrba, Thirupathi Boningari, Panagiotis Smirniotis
The main objective of this work is to develop a low-temperature SCR catalyst as an active, durable and selective for the reduction of nitrogen oxides at cold start conditions. A series of various metal oxide- incorporated zeolite catalysts were prepared by adopting incipient wetness technique, cation-exchange, deposition-precipitation and other synthesis techniques, the resulting catalysts were characterized and tested in a fixed bed continuous flow quartz reactor using ammonia as the reductant. Once the catalysts with the best performance were identified, experiments were performed with the aim of optimizing these formulations with respect to the metal atomic ratio, preparation method, active components and supported metal type. Initial catalyst formulations have been achieved optimum NOx reduction activity at low-temperatures. These catalyst formulations showed a maximum NOx conversion in the temperature range of 100 ºC – 350 ºC (at a GHSV of 80,000 h-1).
2015-04-14
Technical Paper
2015-01-1021
Brad Adelman, Navtej Singh, Paul Charintranond, Greg Griffin, Shyam Santhanam, Ed Derybowski, Adam Lack
Current legislative trends regarding diesel emissions are striving to achieve two seemingly competing goals: simultaneously lowering NOx and Green House Gas (GHG) emissions. These two goals are considered at odds since lower GHG emissions (e.g. CO2) is achieved via high combustion efficiency resulting in higher engine out NOx emissions and lower exhaust gas temperatures. Conversely, NOx reduction technologies such as SCR require temperatures above 200°C for dosing the reductant (DEF). Dosing DEF requires injection pressures around 5 bar. This is required to ensure proper penetration into the exhaust stream as well as generate the appropriate spray pattern and droplet sizes. Dosing DEF generally requires long mixing and/or high turbulence (high restriction) areas so that the aqueous urea solution can be converted into NH3 without deposit formation. One alternative to dosing DEF, an aqueous solution of 32.5% wt urea, is to inject gaseous NH3.
2015-04-14
Technical Paper
2015-01-1036
Lei Liu, Zhijun Li, Boxi Shen
Ensuring lower emissions and better economy (fuel economy and after-treatment economy) simultaneously is the pursuit of future engines. An EGR-LNT synergetic control system was applied to a modified lean-burn gasoline engine of CA3GA2. Results showed that the synergetic control system can achieve a better NOx reduction than sole EGR and sole LNT within a proper range of upstream EGR rate without the penalty in fuel consumption, and it also has the potential to saving noble metal cost in LNT. But more or less upstream EGR rate would make the synergetic control system inefficiency. In order to guarantee the objectivity of the effect of EGR-LNT synergetic control system on NOx Reduction, another modified lean-burn gasoline engine of CA4GA5 was additionally tested. Results verified that proper range of upstream EGR rate in EGR-LNT synergetic control system.
2015-04-14
Technical Paper
2015-01-1031
Nic van Vuuren, Gabriele Brizi, Giacomo Buitoni, Lucio Postrioti, Carmine Ungaro
The recent implementation of new rounds of stringent nitrogen oxides (NOx) emissions reduction legislation in Europe and North America is driving the expanded use of exhaust aftertreatment systems, including those that treat NOx under the high-oxygen conditions typical of lean-burn engines. One of the favored aftertreatment solutions is referred to as Selective Catalytic Reduction (SCR), which comprises a catalyst that facilitates the reactions of ammonia (NH3) with the exhaust nitrogen oxides (NOx). It is customary with these systems to generate the NH3 by injecting a liquid aqueous urea solution, typically at a 32% concentration of urea (CO(NH2)2). The solution is referred to as AUS-32, and is also known under its commercial name of AdBlue® in Europe, and DEF – Diesel Exhaust Fluid – in the USA. The urea solution is injected into the exhaust and transformed to NH3 by various mechanisms for the SCR reactions.
2015-04-14
Technical Paper
2015-01-1033
Raymond Conway, Sougato Chatterjee, Mojghan Naseri, Ceren Aydin
Selective Catalytic Reduction (SCR) catalysts have been demonstrated as an effective solution for controlling NOx emissions from diesel engines. Typical 2013 Heavy Duty Diesel emission control systems include a DOC upstream of a catalyzed diesel particulate filter (CDPF) which is followed by urea injection and the SCR sub-assembly. There is a strong desire to further increase the NOx conversion capability of such systems, which would enable additional fuel economy savings by allowing engines to be calibrated to higher engine-out NOx levels. One potential approach is to replace the CDPF with a diesel particulate filter coated with SCR catalysts (SCRF® technology) while keeping the flow-through SCR elements downstream, which essentially increases the SCR volume in the after-treatment assembly without affecting the overall packaging.
2015-04-14
Technical Paper
2015-01-1221
Jamie Knapp, Adam Chapman, Sagar Mody, Thomas Steffen
Hybrid electric vehicles offer significant fuel economy benefits, because battery and fuel can be used as complementing energy sources. This paper presents the use of dynamic programming to find the optimal blend of power sources, leading to the lowest fuel consumption and the lowest level of harmful emissions. It is found that the optimal engine behavior differs substantially to an on-line adaptive control system previously designed for the Lotus Evora 414E. When analyzing the trade-off between emission and fuel consumption, CO and HC emissions show a traditional Pareto curve, whereas NOx emissions show a near linear relationship with a high penalty. These global optimization results are not directly applicable for online control, because they require knowledge of the whole drive cycle in advance, but they can guide the design of a more efficient hybrid control system.
2015-04-14
Technical Paper
2015-01-0379
Yongli Qi, Xinyu Ge, Lichun Dong
The Hybrid vehicle engines modified for high exhaust gas recirculation (EGR) is a good choice for high efficiency and low NOx emissions. However, high EGR will dilute the engine charge and may cause serious performance problems such as incomplete combustion, torque fluctuation, and engine misfire. An efficient way to overcome these drawbacks is to intensify tumble leading to increased turbulent intensity at the time of ignition. The enhancement of turbulent intensity will increase flame velocity and improve combustion quality, therefore increasing engine tolerance to higher EGR. To achieve the goal of increasing tolerance to EGR, this work reports a CFD investigation of high tumble intake port design using STAR-CD. The validations had been performed through the comparison with PIV experimental tests.
2015-04-14
Technical Paper
2015-01-0383
Changpu Zhao, Gang Yu, Junwei Yang, Man Bai, Fang Shang
Diesel engines generally tend to produce very low level of NOx and soot through the application of Miller Cycle, which is mainly due to the low temperature combustion (LTC) atmosphere resulted from the Miller Cycle utilization. A designed set of Miller-LTC combustion model was analyzed. The CFD model was calibrated against experimental data for part load operation at 3000 r/min. It is found that higher boost coupled with EGR can further tap the potential of Miller-LTC cycle, improving and expanding the Miller-LTC operation condition. The results indicated that the variation of Miller timing can decrease the regions of high temperature and then improve the levels and trade-off relationship of NOx and soot. Peak pressure and NOx emissions were increased dramatically though the problem of insufficient intake charge was resolved by the enhanced intake pressure that is equivalent to dual-stage turbo-charging.
2015-04-14
Technical Paper
2015-01-0389
Zhichao Zhao, Zhengxin Xu, Jingping Liu, Mianzhi Wang, Chia-Fon Lee, Wayne Chang, Jie Hou
A multi-step acetone-butanol-ethanol(ABE) phenomenological soot model was proposed and implemented into KIVA-3V Release 2 code. Experiments were conducted in an optical constant volume combustion chamber to investigate the combustion and soot emission characteristics under 1000K initial temperature with various oxygen concentrations (21%, 16%, 11%). Parallelly, multi-dimensional computational fluid dynamics (CFD) simulations were also conducted at the same operation conditions. The predicted soot mass traces showed good agreement with experimental data. As ambient oxygen decreased from 21% to 11%, ignition delay retarded and the distribution of temperature became more and more homogenous. Compared to 21% ambient oxygen, peak value of total soot mass initially increased at 16% oxygen concentration due to the suppressed soot oxidation mechanism. While at 11% ambient oxygen, both soot formation and oxidation mechanism were further suppressed.
2015-04-14
Technical Paper
2015-01-0394
Nicola Giovannoni, Alessandro d'Adamo, Giuseppe Cicalese, Giuseppe Cantore
Fuel/wall interaction in DISI engines plays a fundamental role on mixture preparation, combustion and pollutant emissions through a wide set of different mechanisms: it contributes to charge stratification and spark targeting, combustion propagation, lube oil dilution, end gas reactivity and fuel deposit formation. Particularly, this last promotes unburnt hydrocarbon and soot particle formation: due to the increasingly stringent emission regulations (EU6 and forthcoming), it is necessary to deeply analyze and well-understand the complex physical mechanisms promoting fuel deposit formation. The task is far from being trivial, due to the coexistence of mutually interacting factors, such as complex moving geometries influencing both impact angle and velocity, time-dependent wall temperatures.
2015-04-14
Technical Paper
2015-01-0854
Jeongwoo Lee, Sanghyun Chu, Jaehyuk Cha, Hoimyung Choi, Kyoungdoug Min
Diesel engine has a superb reputation for its high thermal efficiency, reliability, and durability. However, under conventional diesel combustion of heterogeneous air-fuel mixture, particulate matters (PM) and nitrogen oxides (NOx) emissions have been a challenge to overcome. In an effort to reduce NOx and PM emissions, dual fuel combustion has been introduced recently. Dual fuel combustion is constructed by supplying high volatility fuels on the intake port, while the amount of diesel decreases. Hence, near zero PM emission could be achieved as the substitution ratio of high volatility fuels for diesel increases. In addition, under the dual fuel premixed charge compression ignition (PCCI) combustion, NOx emission could be also reduced comparing to that of conventional diesel combustion. However, there is a limitation for the substitution ratio of high volatility fuels, because many of high volatility fuels such as gasoline or gaseous fuels have poor reactivity for the auto-ignition.
2015-04-14
Technical Paper
2015-01-0843
Anand Nageswaran Bharath, Yangdongfang Yang, Rolf D. Reitz, Christopher Rutland
While Low Temperature Combustion (LTC) strategies such as Reactivity Controlled Compression Ignition (RCCI) exhibit high thermal efficiency and produce low NOx and soot emissions, low load operation is still a significant challenge due to high unburnt hydrocarbon (UHC) and carbon monoxide (CO) emissions, which occur as a result of poor combustion efficiencies at these operating points. Furthermore, the exhaust gas temperatures are insufficient to light-off the Diesel Oxidation Catalyst (DOC), thereby resulting in poor UHC and CO conversion efficiencies by the aftertreatment system. To achieve exhaust gas temperature values sufficient for DOC light-off, combustion can be appropriately phased by changing the ratio of gasoline to diesel in the cylinder, or by burning additional fuel injected during the expansion stroke through post-injection.
2015-04-14
Technical Paper
2015-01-0895
Senthilkumar Masimalai, Venkatesan Kuppusamy, Jaikumar Mayakrishnan
Waste cooking oils (WCOs) find very attractive among other vegetable oils to use as fuel in diesel engines as they are easily available, renewable and most of the properties are very close to diesel. Past studies reported that the effective way of using WCO is by modifying it as biodiesel by transesterification and using as fuel in CI engines. However, producing biodiesel is a complex process and expensive one. In addition biodiesel production results in certain byproducts such as glycerol and fatty acids which cannot be used as fuel in diesel engines. Oxygen enriched combustion finds an attractive and one of the effective methods for reducing smoke and improving performance of slow burning fuels such as vegetable oils and animal fats in compression ignition engines. It is a simple method which needs no modification in the fuel or in the engine to operate a diesel engine.
2015-04-14
Technical Paper
2015-01-0896
Antoine Lacarriere, Thierry Seguelong, Virginie Harle, Clara Fabre
With increasingly severe Particulate Matter (PM)/ Particle Number (PN) regulations across the world the use of Diesel Particulate Filters (DPFs) have become widespread. DPFs using a Fuel Borne Catalyst (FBC) to assist filter regeneration provide a uniquely advantaged DPF technology: The FBC, added to the fuel, is mixed within the soot during the combustion in the engine and the additivated soot is collected in the DPF. This intimate contact between the catalyst and the soot leads to a drastic reduction of the soot combustion temperature (starting at 300 °C) and very fast soot combustion kinetic (down to few minutes) allowing fast and complete DPF regeneration even in the very challenging city driving conditions. Due to DPF's ash accumulation being one of the most important factors limiting the DPF’s service life, FBC's have to be formulated with high efficiency catalyst to minimize ash build up in the DPF.
2015-04-14
Technical Paper
2015-01-0905
Seyed Hadavi, Buland Dizayi, Hu Li, Alison Tomlin
To maximize CO2 reduction, refined straight used cooking oils were used as a fuel in Heavy Good Vehicles (HGVs) in this research. The fuel is called C2G Ultra Biofuel (C2G: Convert to Green) and is a fully renewable fuel made as a diesel replacement from processed used cooking oil, used directly in diesel engines specifically modified for this purpose. This is part of a large demonstration project involving ten 44-ton trucks using C2G Ultra Biofuel as a fuel to partially replace standard diesel fuels. A dual fuel tank containing both diesel and C2G Ultra Biofuel and an on-board fuel blending system-Bioltec system was installed on each vehicle, which is able to heat up the C2G Ultra Biofuel and automatically determine the required blending ratio of diesel and C2G Ultra Biofuel according to fuel temperature and engine load. The engine was started with diesel and then switched C2G Ultra Biofuel.
2015-04-14
Technical Paper
2015-01-0903
Neeraj Mittal, Pradeep Patanwal, M Sithananthan, M Subramanian, Ajay Kumar Sehgal, R Suresh, B P Das
N-butanol is a promising alternative fuel which requires no engine modification when it is used as a blend with diesel. The miscibility of n-butanol with diesel is excellent at a wide range of blending ratio's. N-butanol has high oxygen content & comparable energy content, specific gravity and viscosity that of diesel, which makes it attractive for diesel engines as an alternative fuel. An experimental investigation was conducted to assess the performance of new generation passenger car with respect to power, fuel economy and emissions using 5%, 10% and 20% (by vol.) N-butanol blends with diesel (NBD). Computer controlled DC motor driven chassis dynamometer, Horiba OBD 2200 emission measuring system and AVL FSN smoke meter were used for measuring wide open power, road load simulation (RLS) fuel economy, emissions & smoke in WOT and steady speed driving conditions.
2015-04-14
Technical Paper
2015-01-0898
Leonardo Pellegrini, Carlo Beatrice, Gabriele Di Blasio
Concerns about the limited availability of fossil fuels and the global climate changes have led worldwide to mandates for an increased use of sustainable biofuels. Hydrotreated vegetable oils (HVO), consisting of high cetane number paraffinic hydrocarbons that are free of aromatics, oxygen and sulfur, are an industrial scale alternative to ester–type biodiesel (FAME). A number of studies and large field trials have demonstrated that HVO can be used as a drop-in fuel with beneficial effects for the engine and the environment. However, most studies so far have used state-of-the art engines or vehicles without consideration of the future technical trends, such as the reduction of the compression ratio, the implementation of the closed-loop combustion control (CLCC) and the increase of the EGR rate in order to meet the Euro 6 NOx emission standard.
2015-04-14
Technical Paper
2015-01-0910
Lei Zhou, Benedikt Heuser, Michael Boot, Florian Kremer, Stefan Pischinger
Lignocellulosic biomass consists of (hemi-) cellulose and lignin. Accordingly, an integrated biorefinery will seek to valorize both streams into higher value fuels and chemicals. To this end, this study evaluated the overall combustion performance of both cellulose- and lignin derivatives, namely the high cetane number (CN) di-n-butyl ether (DnBE) and low CN anisole, respectively. Said compounds were blended both separately and together with EN590 diesel. Experiments were conducted in a single cylinder compression ignition engine, which has been optimized for improved combustion characteristics with respect to low emission levels and at the same time high fuel efficiency. The selected operating conditions have been adopted from previous “Tailor-Made Fuels from Biomass (TMFB)” work.
2015-04-14
Technical Paper
2015-01-0908
Yuqiang Li, Karthik Nithyanandan, Jiaxiang Zhang, Chia-Fon Lee, Shengming Liao
Butanol has proved to be a very promising alternative fuel in recent years. The production of bio-butanol, typically done using the acetone-butanol-ethanol (ABE) fermentation process is expensive and consumes a lot of energy. Hence it is of interest to study the intermediate fermentation product, i.e. water-containing ABE as a potential fuel. The combustion and emissions performance of ABE29.5W0.5 (29.5 vol.% ABE, 0.5 vol.% water and gasoline blend), ABE30 (30 vol.% ABE and gasoline blend) and ABE0 (pure gasoline) were investigated in this study. The results showed that ABE29.5W0.5 enhanced engine torque by 9.6%-12.7% and brake thermal efficiency (BTE) by 5.2%-11.6% compared to pure gasoline, respectively. ABE29.5W0.5 also showed similar brake specific fuel consumption (BSFC) relative to pure gasoline.
2015-04-14
Technical Paper
2015-01-1626
Qingning Zhang, Andrew Pennycott, Richard Burke, Sam Akehurst, Chris Brace
Nitrogen oxides emissions are an important aspect of engine design and calibration due to increasingly strict legislation. As a consequence, accurate modeling of nitrogen oxides emissions from diesel engines could play a crucial role during the design and development phases of vehicle powertrain systems. In this paper, artificial neural networks using a number of engine variables as inputs including torque, speed, oil temperature and variables related to fuel injection are developed as a method of modeling and predicting the production of nitrogen oxides. Nonlinear autoregressive networks with exogenous inputs are identified and validated using data from dynamometry tests. The models predict exhaust nitrogen oxide concentrations under different engine conditions with satisfactory accuracy.
2015-04-14
Technical Paper
2015-01-1631
Michinori Tani, Atsuhiro Miyauchi, Yoshiaki Matsuzono
Stringent emission regulations for passenger vehicles are demanded. Reducing costs of high-grade exhaust gas after-treatment systems is necessary. The demand for high-precision engine air-fuel ratio control remains high. Higher efficiency in development and shortening of the development period are required, and control system construction that is accomplished in a short period regardless of the developer's technical skills and can harness the hardware potential has become essential. To achieve high-precision control, there is a trial-and-error element in configuration such as feedback-gain settings, and the tradeoff between high-precision air-fuel ratio control and shortening of the development period. We investigated a system based on a control method that constantly performs optimum air-fuel ratio feedback control to suit air-fuel ratio sensor responsiveness that changes with vehicle driving conditions, and eliminates the trial-and-error element.
2015-04-14
Technical Paper
2015-01-1637
SeungBum Kim, SeongMin Park, DongUk Han
This paper focuses on the vehicle test result of the US fuel economy test cycles such as FTP75, HWY and US06 with model based Cooled EGR system. Cooled EGR SW function was realized by Model Based Development (internal rapid prototyping) using iRPT tool. With EGR, mixing exhaust gas with clean air reduces the oxygen concentration in the cylinder charge, as a result, the combustion process is slowed, and the combustion temperature drops. This experiment confirmed that the spark timing was more advanced without knocking and manifold pressure was increased in all cases with EGR. A positive potential of fuel economy improvement on FTP mode, US06 mode have seen in this experiment but not for HWY where the engine load is quite low and the spark advance is already optimized. As a result, fuel economy was increased by maximum 3.3% on FTP, 2.7% on US06, decreased by 0.3% on HWY mode respectively with EGR.
2015-04-14
Technical Paper
2015-01-1639
Indranil Brahma, Odinmma Ofili, Matthew Campbell, Henrique Chiang, Vincent Giralo, Peter Stryker, Daniel Johnson, Aaron Clark
EGR flow rate measurements on production engines are commonly made using orifices or flow nozzles. These devices increase the exhaust pressure resulting in an increase in fuel consumption. Further, the discharge coefficient of these devices have been experimentally determined and tabulated as a function of Reynolds number in published literature only for steady sate flow, and not pulsating flow that occurs in engines. In this work the pressure drop across the EGR cooler (∆P) has been investigated for its ability to predict mass flow rate in conjunction with the inlet temperature measurement. It has been shown that an equivalent discharge coefficient can be defined for the entire EGR cooler, and that this discharge coefficient is a function of the Reynolds number at the inlet of the cooler. Steady state measurements have been made over a variety of speeds and loads and all the data have been shown to collapse onto one single curve when plotted against Reynolds number.
2015-04-14
Technical Paper
2015-01-1638
Dejan Kihas, Michael R. Uchanski
Due to stringent emissions regulations, engine-out NOx has emerged as a critical signal for control and on-board diagnosis (OBD) of diesel engines and their aftertreatment systems. A physical NOx sensor mounted upstream of NOx aftertreatment devices often provides this essential signal. Recently, numerous researchers and OEMs have used on-ECU computations to estimate the engine-out NOx level. Such work is typically undertaken to either improve OBD monitors or to lower bill of material cost by removing the sensor. These on-ECU NOx estimators are sometimes called inferential sensors or virtual sensors. This paper reviews the literature on-ECU embedded NOx inferential sensors in order to paint a picture of the current state of the art and to identify directions for future work.
2015-04-14
Technical Paper
2015-01-0849
Mufaddel Dahodwala, Satyum Joshi, Erik Koehler, Michael Franke, Dean Tomazic
Substitution of diesel fuel with natural gas in heavy-duty diesel engines offers significant advantages in terms of operating cost, as well as NOx, PM emissions and greenhouse gas emissions. However, the challenges of high HC and CO emissions, combustion stability, exhaust temperatures and pressure rise rates limit the substitution levels across the engine operating map and necessitate an optimized combustion strategy. Reactivity controlled compression ignition (RCCI) combustion has shown promise in regard to improving combustion efficiency at low and medium loads and simultaneously reducing NOx emissions at higher loads. RCCI combustion exploits the difference in reactivity between two fuels by introducing a less reactive fuel, such as natural gas, along with air during the intake stroke and igniting the air-NG mixture by injecting a higher reactivity fuel, such as diesel, later in the compression stroke.
2015-04-14
Technical Paper
2015-01-1073
Yoshitaka Ito, Takehide Shimoda, Takashi Aoki, Kazuya Yuuki, Hirofumi Sakamoto, Kyohei Kato, Dominic Thier, Philipp Kattouah, Etsuji Ohara, Claus Vogt
Starting with Euro 6 there will be a Particle Number (PN) limit for GDI vehicles. In addition further certification of Real Driving Emissions (RDE) is considered. RDE tests require low and stable emissions in a wide range of engine operation, which must be durable for 160,000 km. To achieve such stringent targets a ceramic wall-flow Gasoline Particulate Filter (GPF) is one potential novel emission control device. This paper focusses on a catalyzed GPF combining particle trapping and catalytic conversion in one single device. The main parameters to consider when introducing this technology are filtration efficiency, backpressure and catalytic conversion. This paper portraits a detailed study starting from the choice of material recipe, design optimization, engine bench evaluation and final validation inside a standard vehicle from the market during an extensive field test up to 160,000 km on public roads.
Viewing 61 to 90 of 22750

Filter