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Viewing 31 to 60 of 23331
2016-10-17
Technical Paper
2016-01-2179
Marius Zubel, Om Parkash Bhardwaj, Benedikt Heuser, Bastian Holderbaum, Sebastian Doerr, Jukka Nuottimäki
The present work represents a continuation of the earlier results published by the authors on combustion and emission investigation of neat Hydrogenated Vegetable Oil (HVO) in a High Efficiency Diesel Combustion System (SAE Int. J. Fuels Lubr.: 2013-01-1677, 2014-01-2846). The results indicate a significant reduction in CO-, HC- and Noise emissions at constant NOx levels. With regards to soot emissions, at higher part loads the aromatic free, paraffinic composition of HVO shows a significant reduction than EN 590 petroleum Diesel but at lower loads the high cetane number leads to shorter ignition delays, and therefore, ignition under richer conditions caused slightly increased soot emissions. This drawback could be compensated with an optimized engine calibration but in this work, an advanced fuel formulation approach is investigated to further improve the emission behavior.
2016-10-17
Technical Paper
2016-01-2183
Yann Gallo, Zheming Li, Mattias Richter, Oivind Andersson
Soot formation and soot oxidation are the two competing processes governing soot emissions from Diesel engines. Previous studies have been showing a poor correlation between soot formation rate and soot emissions. This article presents a systematic study of a number of parameters affecting soot oxidation rate and the correlation with soot emissions. An optical heavy-duty engine has been used in conjunction with a laser extinction setup in order to collect time resolved data of the soot concentration in the cylinder during the expansion phase. Laser extinction is measured using a red (685nm) laser beam, which is sent vertically through the cylinder. This wavelength was chosen long enough to minimize absorption interference from polycyclic aromatic hydrocarbons, while still in the visible regime. It is modulated in order to produce 10 pulses per crank angle degree.
2016-10-17
Technical Paper
2016-01-2216
Brad Richard, Martha Christenson, Deborah Rosenblatt, Aaron Conde
Five Ford Transit Connect vans, operating on alternative fuels and propulsion systems, were tested on a chassis dynamometer. The vehicles were powered with petrol, low blend ethanol (E10), compressed natural gas (CNG), liquefied petroleum gas (LPG), and an electric battery. Four test cycles were used representing city driving and cold-start (FTP-75), aggressive high speed driving (US06), free flow highway driving (HWFCT), and a combination of urban, rural, and motorway driving (WHVC). Tests were performed at temperatures of 22°C, with select tests at -7oC and -18°C. Exhaust emissions were measured and characterized including, on all cycles, CO, NOX, THC, TPM (except on WHVC), and CO2. On the FTP-75, WHVC, and US06 cycles additional exhaust emission characterization included N2O, and CH4. On the FTP-75 and WHVC, carbonyl compounds and volatile organic compounds (VOCs) were also characterized.
2016-10-17
Technical Paper
2016-01-2256
Kristin Götz, Barbara Fey, Anja Singer, Juergen Krahl, Jürgen Bünger, Markus Knorr, Olaf Schröder
The climate target of the European Union (EU) is the reduction of 40 % greenhouse gas reduction from the 1990s level by 2030 [1]. Currently the transport sector is one of the biggest greenhouse gas emission producer in the EU [2]. Drop-in biofuels can contribute to the reduction of GHG emissions in the transport sector and so as well the total GHG emissions. Diesel R33, a new developed biofuel enables sustainable mobility fulfilling the European diesel fuel specification and can reduce the GHG emissions of about 17 % versus fossil diesel fuel. Diesel R33 is made from seven percent used cooking oil methyl ester, 26 percent hydrotreated vegetable oil (HVO) and 67 percent high quality diesel fuel. HVO was produced from rapeseed and palm oil. This new biofuel was tested in a fleet of 280 vehicles (passenger cars, light duty vehicles, off-road vehicles and urban buses) covering all emission classes.
2016-10-17
Technical Paper
2016-01-2187
Haifeng Liu, Huixiang Zhang, Hu Wang, Xian Zou, Mingfa Yao
The combustion in low-speed two-stroke marine diesel engines can be characterized as large spatial and temporal scales combustion. One of the most effective measures to reduce NOx emissions is to reduce the local maximum combustion temperature. In the current study, multi-dimensional numerical simulations have been conducted to explore the potential of Miller cycle, high compression ratio coupled with EGR (Exhaust Gas Recirculation) and WEF (water emulsified fuel) to improve the trade-off relationship of NOx-ISFC (indicated specific fuel consumption) in a low-speed two-stroke marine engine. The results show that the EGR ratio could be reduced combined with WEF to meet the Tier III emission regulation. The penalty on fuel consumption with EGR and WEF could be offset by Miller cycle and high geometric compression ratio.
2016-10-17
Technical Paper
2016-01-2354
Aaron J. Conde, Louis-Philippe Gagne, Martha Christenson, Brad Richard, Ian Whittal
Six vehicles were tested on a chassis dynamometer in order to characterize the differences in vehicle performance between vehicles equipped with various AWD powertrains and their 2WD counterparts. Three pairs of vehicle models from three separate vehicle manufacturers were chosen. The first two vehicle models are AWD vehicles that are equipped with a differential split that can deliver power the rear axle, when needed. The third vehicle employs an axle disconnect system which completely disconnects the rear axle, allowing the vehicles to operate in 2WD. 2WD vehicles were tested on a single-axle dynamometer and the AWD vehicles were tested on a double-axle dynamometer. Each vehicle was tested on four different drive cycles (FTP-75, HWFCT, US06, Cold FTP) as well as the SC03 drive cycle, when available. Vehicle emissions were measured for all cycles including CO, CO2, NOX, THC, and TPM.
2016-10-17
Technical Paper
2016-01-2181
Yong Qian, Yahui Zhang, Liang Yu, Zhen Huang, Xing-cai Lu
In this paper, an experimental study based on a modified single cylinder diesel oil engine has been conducted to study the effects of diesel oil blending different iso-alkanes on the combustion and emissions. Iso-octane, iso-dodecane and 2,2,4,4,6,8,8-Heptamethylnonane (HMN) were chosen as iso-alkanes. During the experiment, the direct injection timing was kept at 7 oCA BTDC, and the injection pressure was maintained at 120MPa. The study found that after blending iso-alkanes, the changes of fuel physical properties have significant effects on the heat release phase under low load. However, the effects are weakened gradually with the improvement of loads. The peak value of heat release curves and the maximum pressure rising rate gradually increase with the improvement of loads after mixing with iso-alkanes.
2016-10-17
Technical Paper
2016-01-2300
Mengqin Shen, Martin Tuner, Bengt Johansson, Per Tunestal, Joakim Pagels
In order to reduce NOx and soot emissions while maintaining high thermal efficiency, more advanced combustion concepts have been developed over the years, such as Homogeneous Charge Compression Ignition (HCCI) and Partially Premixed Combustion (PPC), as possible combustion processes in commercial engines. Compared to HCCI, PPC has advantages of lower UHC and CO emissions; however, on the other hand, soot emissions can be a challenge when adding Exhaust-Gas Recirculation (EGR) gas due to increased fuel stratifications. The current work presents particle size distribution measurements performed from HCCI-like combustion with very early (120 CAD BTDC) to PPC combustion with late injection timing (11 CAD BTDC). Combustion phasing was fixed by adjusting inlet temperature at two intake oxygen rates, 21% and 15% respectively. Particle size distributions were measured using a differential mobility spectrometer DMS500.
2016-10-17
Technical Paper
2016-01-2327
Scott Eakle, Svitlana Kroll, Cary Henry
Ideally, complete decomposition of urea should produce only two products in active Selective Catalytic Reduction (SCR) systems: ammonia and carbon dioxide. In reality, urea decomposition reaction is a two-step process that includes the formation of ammonia and isocyanic acid as intermediate products via thermolysis. Being highly reactive, isocyanic acid can initiate the formation of larger molecular weight compounds such as cyanuric acid, biuret, melamine, ammeline, ammelide, and dicyandimide. These compounds can be responsible for the formation of deposits on the walls of the decomposition reactor in urea SCR systems. Composition of these deposits varies with temperature exposure, and under certain conditions can create oligomers that are difficult to remove from exhaust pipes. Deposits can affect efficiency of the urea decomposition, and if large enough, can inhibit the exhaust flow and negatively impact ammonia distribution on the SCR catalyst.
2016-10-17
Technical Paper
2016-01-2172
Matthieu Cordier, Olivier Laget, Florence Duffour, Xavier Gautrot, Loic De Francqueville
Increasing global efficiency of direct injection spark ignition (DISI) engine is nowadays one of the main concerns in automotive research. Emissions regulations such as EURO6+ are more and more stringent and automotive industry needs to comply with objective of greenhouse gas production to limit global warming phenomenon. Currently, the conventional way to reduce DISI engine fuel consumption is the Downsizing. This approach is well suited to the current homologation cycle as NEDC, but has the drawback to induce strong over-consumptions in the frame of customer real driving usage. Moreover, the driving cycles dedicated to EURO 7 and future regulations will evolve towards usage ranges including higher load operations with higher particulate emissions. Consequently, limitations in terms of emitted particles will be especially as constraining.
2016-10-17
Technical Paper
2016-01-2320
Tsuyoshi Asako, Ryuji Kai, Tetsuo Toyoshima, Claus Vogt, Shogo Hirose, Shiori Nakao
Ammonia Selective Catalytic Reduction (SCR) is adapted for a variety of applications to control NOx in diesel engine emission. Most commonly used catalyst for SCR in established markets is Cu-Zeolite due to excellent NOx conversion and thermal durability. However, most applications in emerging markets and certain applications in established markets utilize Vanadia SCR. The operating temperature is typically maintained below 550C to avoid vanadium sublimation due to passive regeneration of diesel particulate filter (DPF) or eliminating DPF from aftertreatment system. For DPF-less system, particulate matter (PM) standard is achievable without DPF depending on engine tuning. Further improvement of Vanadia SCR durability and NOx conversion at low exhaust gas temperatures will be required in consideration of future emission standards.
2016-10-17
Technical Paper
2016-01-2351
Kotaro Tanaka, Kazuki Hiroki, Tomoki Kikuchi, Mitsuru Konno, Mitsuharu Oguma
Exhaust gas recirculation (EGR) is widely used in diesel engines to reduce nitrogen oxide (NOx) emissions. However, a kind of lacquer is formed on the EGR valve or EGR cooler because of the particulate matters and other components present in diesel exhaust, which are serious problems. In this study, the mechanism of the lacquer deposition has been investigated using attenuated total reflection Fourier transform infrared (ATR-FTIR) spectrometer, which allows for in situ measurements of the surface of the depositing lacquer. Scanning electron microscope (SEM) was also used to perform detail observation of the lacquer. Deposition of temperature-dependent lacquers was evaluated by varying the temperature of a diamond prism between 353 K and 393 K in ATR-FTIR that was set to a custom-built sample line, which branched off from the exhaust pipe of the diesel engine.
2016-10-17
Technical Paper
2016-01-2174
Reza Golzari, Yuanping Li, Hua Zhao
As the emission regulations for internal combustion engines are becoming increasingly stringent, different solutions have been researched and developed, such as downsizing combined with single and multistage boosting (turbocharging and/or supercharging), dual injection and fuelling systems, variable valve timing and lift devices, variable compression and expansion ratio using Miller and Atkinson cycles. The aim of these systems is to improve the in-cylinder mixture quality and therefore enhance the combustion which ultimately increases thermal efficiency and fuel economy while lowering the emissions. This paper describes the effects of dual injection systems on combustion, efficiency and emissions of a downsized single cylinder gasoline direct injection spark ignited (DISI) engine equipped with variable cam phasing on both the intake and exhaust cams.
2016-10-17
Technical Paper
2016-01-2324
Xiaoguo Tang, Dan McBryde
When IC engine (gasoline & diesel) and hybrid powertrain operating off the desired conditions, the combustion process, therefore the exhaust components (chemical / physical info) will be different. A modern motor vehicle has to have well controlled engine feed_gas and very high catalyst efficiency to meet EPA standards, only few percent (x%) engine output emissions allowed to emit. When ECM_Cat emission control failed, vehicle tailpipe will have ((100%)/(x%)) times change (10~50 times), or more (ECM off stoich). If engine emission control system fails or a defeat device existed, the ICE exhaust will show different signatures (on TWC failure, unexpected enrich, less SOC swing in real driving, failed De-NOx…). A simple short piece of exhaust pipe equipped with: a thermocouple, NOx_lambda sensor can pick up the information for pattern recognition analysis.
2016-10-17
Technical Paper
2016-01-2282
Toru Uenishi, Eijiro Tanaka, TAKAO FUKUMA, Jin Kusaka, Yasuhiro Daisho
Experimental and numerical studies were conducted on diesel particulate filter (DPF) under different Particulate Matter (PM) loading and DPF regeneration conditions.Pressure losses across DPF loaded with PM having different mean particle diameters and regenerated with introducing hot gas created in Diesel Oxidation Catalyst(DOC)with oxidized hydrocarbon injected by fuel injector place on exhaust gas pipe were measured by introducing exhaust gases from a 2.2 liter inline four- cylinder, TCI diesel engine designed for use in passenger cars.Pressure drops across DPF loaded with PM having larger mean particle diameters expressed smaller than smaller mean particle diameters in PM loading phase.Meanwhile, the combustion amount and the decrease of pressure losses across DPF loaded with PM having larger mean particle diameters expressed smaller than smaller mean particle diameters in DPF regeneration phase.A mechanistic hypothesis was then proposed to explain the observed trends,accounting for the effects of the soot loading regime in the wall and the soot cake layer on the pressure drop.This hypothesis was used to guide the development and validation of a numerical model for predicting the pressure drop in the DPF.The relationship between the permeability and the porosity of the wall and soot cake layer was modeled under various soot loading conditions.The percolation coefficient at which the soot filtering regime changed from wall trapping to cake layer trapping was also determined by considering the filtering efficiency.The activation energy and exponential factor in the reaction rate constant was calibrated by each the mean diameter of secondary soot particles.The model was validated by comparing its output to the results of experimental test cell studies and used to analyze transport phenomena in particular filters.
2016-10-17
Technical Paper
2016-01-2208
Zifeng Lu, Jeongwoo Han, Michael Wang, Hao Cai, Pingping Sun, David Dieffenthaler, Victor Gordillo, Jean-Christophe Monfort, Xin He, Steven przesmitzki
Gasoline Compression Ignition (GCI) engines using a low octane gasoline-like fuel (LOF) have good potential to achieve lower NOx and lower particulate matter emissions with higher fuel efficiency compared to the modern diesel compression ignition (CI) engines. In this work, we conduct a well-to-wheels (WTW) analysis of the greenhouse gas (GHG) emissions and energy use of the potential LOF GCI vehicle technology. A detailed linear programming (LP) model of the US Petroleum Administration for Defense District Region (PADD) III refinery system - which produces more than 50% of the US refined products - is modified to simulate the production of the LOF in petroleum refineries and provide product-specific energy efficiencies. Results show that the introduction of the LOF production in refineries reduces the throughput of the catalytic reforming unit and thus increases the refinery profit margins.
2016-10-17
Technical Paper
2016-01-2326
Ahmad Khalfan, Gordon Andrews, Hu Li
The tailpipe exhaust emissions were measured under real world urban driving conditions by using a EURO4 emissions compliant SI car equipped with an on-board heated FTIR, a differential GPS for velocity, altitude and position, thermal couples for temperatures, and a MAX fuel meter for transient fuel consumption. Emissions species were measured at 0.5 Hz. The tests were designed to enable the engine fully warmed up journeys to occur into congested traffic, typical of the people situation living alongside congested roads in a large city. Journeys at various times of the day were conducted to investigate traffic conditions impacts such as traffic and pedestrian lights, grade and turning on emissions, engine thermal efficiency and fuel consumption. Four most congested journeys conducted at rush hours and four least congested journeys conducted at free flow periods were selected for comparison.
2016-10-17
Technical Paper
2016-01-2330
Svitlana Kroll, E. Robert Fanick, Kristin Favela
Although the internal combustion engine has been used for more than a century, significant improvements in energy efficiency and emissions reduction are still possible. Advanced combustion strategies used to improve efficiency, emissions, and performance alter the chemical composition of engine-out emissions. Changes in exhaust chemistry affect the performance of typical exhaust aftertreatment devices used to meet tailpipe emissions standards and require new strategies and technologies for aftertreatment controls. The characterization of exhaust chemistry from advanced internal combustion engines requires a chemistry speciation and analytical system capable of measuring a wide range of compounds from raw exhaust samples. The widely accepted Auto/Oil procedure is used to quantify hydrocarbon compounds between C1 and C12 from dilute engine exhaust in Tedlar polyvinyl fluoride (PVF) bags.
2016-10-17
Technical Paper
2016-01-2329
Pooyan Kheirkhah, Patrick Kirchen, Steven Rogak
Soot emissions from direct-injection engines are highly sensitive to the fuel-air mixing process, and may vary between combustion cycles due to turbulence and injector instability. Conventional exhaust emissions measurements cannot resolve inter- or intra-cycle variations in particle emissions, which can be important during transient engine operations where a few cycles can disproportionately affect the total exhaust soot. The Fast Exhaust Nephelometer (FEN) is introduced here to use light scattering to measure particulate matter concentration and size near the exhaust port of an engine with a time resolution of 0.1 millisecond. The FEN operates at atmospheric pressure, sampling near the engine exhaust port and uses a laser diode to illuminate a small measurement volume. The scattered light is focused on two amplified photodiodes, sampled synchronous with engine crankshaft encoder.
2016-10-17
Technical Paper
2016-01-2322
Michael Lance, Andrew Wereszczak, Todd J. Toops, Richard Ancimer, Hongmei An, Junhui Li, Leigh Rogoski, Petr Sindler, Aaron Williams, Adam Ragatz, Robert L. McCormick
This study examined the effect of Na contamination in biodiesel on the durability of a diesel emission control system consisting of DOC, DPF, and SCR components when operated with a B20 blend. Biodiesel (B100) is limited to 5 ppm alkaline (Na and K) and 5 ppm alkaline earth (Ca and Mg) metals in ASTM D6751, leading to a maximum of 1 ppm of each type of metal in a B20 blend. These limits exist to protect fuel injection equipment. The objective of this study was to determine if they adequately for protect emission control system components. An OEM production exhaust system was subjected to a simulated 435,000-mile aging on an engine test stand using B20 doped with 14 ppm Na. Hot start FTP NOx emissions rose above the certification value of 0.33 g/bhp-h half way through the test. Sequentially replacing aged DOC, DPF, and SCR devices with degreened parts and conducting hot start FTP tests showed that 65% of the NOx increase was due to DOC/DPF aging and 35% was from SCR degradation.
2016-10-17
Technical Paper
2016-01-2169
Carrie M. Hall, James Sevik, Michael Pamminger, Thomas Wallner
The high octane rating and more plentiful domestic supply of natural gas make it an excellent alternative to gasoline. Using natural gas in dual fuel engines provides one possible strategy for leveraging the advantages of both natural gas and gasoline and such engines have shown the potential to improve overall engine efficiencies. While the benefits of these engine structures are still being explored, one concern with natural gas combustion is its tendency for more incomplete combustion particularly when direct injected. Because of such combustion differences, pollutant formation may vary dramatically for different blends of gasoline and natural gas. This study explores the variations in speciated hydrocarbon emissions which occur for different fuel blends of E10 and compressed natural gas and for different fuel injection strategies.
2016-10-17
Technical Paper
2016-01-2209
Uisung Lee, Jeongwoo Han, Michael Wang, Jacob Ward, Elliot Hicks, Dan Goodwin, Rebecca Boudreaux, Per Hanarp, Henrik Salsing, Parthav Desai, Emmanuel Varenne, Patrik Klintbom, Werner Willems, Sandra L. Winkler, Heiko Maas, Robert De Kleine, John Hansen, Tine Shim, Erik Furusjö
Dimethyl Ether (DME) is an alternative to diesel for use in specially designed compression ignition diesel engines. A key advantage of using DME is the potential for reaching ultralow levels of regulated emissions using simple exhaust aftertreatment technologies and the absence of soot. DME can be produced from natural gas or from renewable feedstocks such as landfill gas or renewable natural gas from waste streams. This study investigates the well-to-wheels (WTW) energy use and emissions of several DME pathways as compared with those of petroleum gasoline and diesel using the Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET) model that is developed at Argonne National Laboratory. The DME pathways include small scale DME production from landfill gas, manure-based biogas and methanol from fossil natural gas (NG), and large scale DME production directly from fossil NG.
2016-10-17
Technical Paper
2016-01-2213
Tomoaki Ito, Makoto Nagata
Diesel exhaust emission control systems often contain DOC (Diesel Oxidation Catalyst) + CSF (Catalyzed Soot Filter) components. In this system PM (particulate matter) is filtered and accumulated in the CSF and such filtered PM is periodically combusted by supplying heat to the CSF. The heat to CSF is generated within the DOC by an exothermic reaction with extra fuel supplied to the DOC. Here the exothermic performance of DOC depends on not only the active catalytic site (such as Pt and/or Pd) but also on the characteristics of the porous material supporting the precious metals. Various properties of Al2O3, i.e. pore diameter, pore volume, BET, acidity, basicity and the Ea (activation energy) of fuel combustion, used in DOCs and PGM particle size of each DOC were measured. The fuel combustion performance of each DOC was evaluated by diesel engine bench.
2016-10-17
Technical Paper
2016-01-2212
Peter Larsson, Will Lennard, Jessica Dahlstrom, Oivind Andersson, Per Tunestal
Yearly 3.3 million premature deaths occur worldwide due to air pollution and NOx pollution counts for nearly one seventh of those. This makes exhaust after-treatment a very important research and hase caused the permitted emission levels for NOx to decrease to very low levels, for EURO 6 only 0.4 g/kWh. Recently new legislation on ammonia slip with a limit of 10 ppm NH3 has been added which makes the SCR-technology more challenging. This technology injects small droplets of an aqueous UREA solution into the stream of exhaust gases and through a catalytic reaction within the SCR-catalyst, NOx is converted into Nitrogen and Water. To enable the catalytic reaction the water content in the UREA solution needs to be evaporated and the ammonia molecules need to have sufficient time to mix with the gases prior to the catalyst.
2016-10-17
Technical Paper
2016-01-2211
Peter Larsson, Will Lennard, Oivind Andersson, Per Tunestal
Increased research is being driven by the automotive industry facing challenges, requiring to comply with both current and future emissions legislation, and to lower fuel consumption. The reason for this legislation is to restrict the harmful pollution which every year causes 3.3 million premature deaths worldwide. One factor that causes this pollution is NOx emissions. NOx emission legislation has been reduced from 8 g/kWh (Euro 1) down to 0.4 g/kWh (Euro 6) and recently new legislation for ammonia slip results in even more challenge for the SCR technology. In order to achieve a good NOx conversion together with a low slip of ammonia, small droplets of UREA solution need to be injected which can be rapidly evaporated and mixed into the flow of exhaust gases.
2016-10-17
Technical Paper
2016-01-2281
Simon Dosda, David Berthout, Gilles Mauviot, Adeline Nogre
With the upcoming Euro 6c emission regulations, the performance of Diesel exhaust lines needs to be improved to meet the NOX and soot emission targets. A promising exhaust line architecture to meet these requirements is the association of a Diesel Oxidation Catalyst (DOC), a Selective Catalytic Reduction coated on a particulate filter (SCR-F) and a Selective Catalytic Reduction (SCR) catalyst. To develop this system, the car manufacturers have to face several challenges. One of the first is the design of the exhaust line volumes, which has a strong impact on the light-off temperatures of the catalysts and so on system performance. Then, urea injection has to be optimized with an adapted control system to maximize NOx reduction while keeping low tailpipe ammonia emission. Moreover, performance degradation of catalysts due to harsh exhaust conditions during vehicle life time have to be detected by OBD system.
2016-10-17
Technical Paper
2016-01-2265
Ashraya Gupta, Dhruv Gupta, Naveen Kumar
The diesel engine has for many decades now assumed a leading role in both the medium and medium–large transport sector due to their high efficiency and ability to produce high torque at low RPM. Furthermore, energy diversification and petroleum independence are also required by each country. In response to this, biodiesel is being considered as a promising solution due to its high calorific value and lubricity than conventional petroleum diesel. However, commercial use of biodiesel has been limited because of some drawbacks including corrosivity, instability of fuel properties, higher viscosity, etc. Biodiesel are known for lower CO, HC and PM emissions. But, on the flip side they produce higher NOx emissions. The addition of alcohol to biodiesel diesel blend can help in reducing high NOx produced by the biodiesel while improving some physical fuel properties.
2016-10-17
Technical Paper
2016-01-2184
Manuel A. Gonzalez D, Davide Di Nunno
Future more stringent requirements for emissions reductions and higher fuel economy require more efficient higher energy extraction in the cylinder, trending to lower exhaust gas temperatures, challenging the energy availability for after treatment components. Methods are required to increase the efficiency of the exhaust thermal management, and Internal Exhaust Gas Recirculation (I-EGR) can increase the exhaust temperature in favor of earlier after treatment activation or for maintaining sustained higher after treatment efficiencies. I-EGR capability has been studied in a Diesel engine through the secondary opening of exhaust valves for more efficient recirculation of exhaust gases from a previous engine cycle to the cylinder mass charge during the intake stroke. I-EGR alone could increase exhaust gas temperature up to a limit soot emissions.
2016-10-17
Technical Paper
2016-01-2215
Hubertus Ulmer, Ansgar Heilig, Simon Bensch, Timo Schulteis, Jan-Kirsten Grathwol, Felix Gollmer, Christian Hofrath, Matthias Rühl
In today’s research and development efforts for combustion engines and the automotive sector in general, the reduction of fuel consumption and therefore CO2 emissions is a major objective. Besides optimizations regarding the burn process and the frictional losses of an engine, the smart and need-based use and control of present engine systems can be a key feature towards low fuel consumptions. In this context, the envisaged paper will focus on the low pressure fuel path of Diesel CR-Systems. A self-programmed 1D Matlab-Simulink model, implementing fluid flow physics, will be presented. The 1D approach is enhanced by a 3D CFD model for considering complex geometries of several fuel path components. Validations and further developments of the model were carried out by car driving tests (NEDC), and experimental data from a test bench, carrying the complete low pressure path.
2016-10-17
Technical Paper
2016-01-2231
Aras Mirfendreski, Andreas Schmid, Michael Grill, Michael Bargende
Longitudinal models are used to evaluate different vehicle-engine concepts with respect to driving behavior and emissions. The engine is generally map-based. An explicit calculation of both fluid dynamics inside the engine air path and cylinder combustion is not considered due to long computing times. Particularly for dynamic certification cycles (WLTC, US06 etc.), dynamic engine effects severely influence the quality of results. Hence, an evaluation of transient engine behavior with map-based engine models is restricted to a certain extent. The coupling of detailed 1D-engine models is an alternative, which rapidly increases the model computation time to approximately 300 times higher than that of real time In many technical areas, the Fourier Transformation (FT) method is applied, which makes it possible to represent superimposed oscillations by their sinusoidal harmonic oscillations of different orders.
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