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Viewing 151 to 180 of 22757
2015-04-14
Journal Article
2015-01-1043
Xian Shi, Reinhard Seiser, Jyh-Yuan Chen, Robert Dibble, Robert Cattolica
Abstract Steady-state, transient and dithering characteristics of emission conversion efficiencies of three-way catalysts on natural gas IC engine were investigated experimentally on a single-cylinder CFR engine test bench. Steady-state runs were conducted as references for specific engine emission levels and corresponding catalyst capacities. The steady-state data showed that conversion of HC will be the major problem since conversion of HC was effective only for a very narrow range of exhaust mixture. Unsteady exploration runs with both lean-to-rich and rich-to-lean transitions were conducted. These results were interpreted with a time scale analysis, according to which a qualitative oxygen storage model was proposed featuring the difference between oxygen absorption and desorption rates on the palladium catalysts.
2015-04-14
Journal Article
2015-01-1042
Ralf Moos
Abstract The state of catalysts and filters plays a key role in automotive exhaust gas aftertreatment. The soot or ash loading of particulate filters, the oxygen loading degree of three-way catalysts, the amount of stored ammonia in SCR catalysts, or the NOx loading degree in NOx storage catalysts are important parameters. Today, they are determined indirectly and/or model-based, calibrated by gas sensors installed up- or downstream of the catalysts or by a differential pressure sensor. This contribution overviews a novel approach to determine directly the catalyst state by a microwave-based technique. For that purpose, the catalyst housing serves as a cavity resonator. As “sensing” element, one or two simple antennas are mounted in the catalyst canning. The electrical properties of the catalyst device, i.e., of the ceramic honeycomb incl. coating and storage material, can be measured.
2015-04-14
Journal Article
2015-01-1035
Yanxiang Yang, Bingqian Tan, Changwen Liu, Ping Zhang, Daguang Xi
Abstract A versatile liquid dosing device along with its metering theory, which can be applied to both SCR dosing system and DPF regeneration system of IC engine after-treatment system, is presented in this paper. The device is composed of a solenoid driven plunger pump, a nozzle and a pressure tube, and is pump-end controlled by PWM signals. Both electrically resistive and conductive liquids including DEF for SCR system, fuel for DPF regeneration, and gasoline for spark ignition engine, can be dispensed quantitatively with this device. A metering theory determining the liquid discharged per injection is developed by studying the system using a physical-mathematical model. The study shows that the liquid discharge can be well correlated with a measurable variable T3, which is associated with the net output energy. Experimental investigations verified that the metering results were independent of the state changes.
2015-04-14
Journal Article
2015-01-1037
Colin L. Weeks, Dan R. Ibeling, Sonia Han, Lindsey Ludwig, Ponnaiyan Ayyappan
Abstract An aqueous urea solution is used as the source of ammonia for selective catalytic reduction (SCR) of NOx to reduce the emissions of NOx in the exhaust of diesel vehicles. However, the decomposition of urea into ammonia is not always complete, resulting in solid urea deposit formation in the decomposition tube or on the SCR catalyst. These solid deposits can impede the flow of the exhaust gases (and uniformity of NH3 supply) and reduce SCR catalyst performance over time. To minimize the formation of urea deposit and to meet EPA NOx emission regulations, it is important to understand the chemistry of formation or removal of the deposit in the decomposition tube and SCR catalyst. In this report, IR spectroscopy, UV-visible spectroscopy, thermogravimetric analysis and elemental analysis have been used to determine the chemical composition of the solid urea deposits formed by the thermal decomposition of urea.
2015-04-14
Journal Article
2015-01-1081
Axel Maier, Ulrike Klaus, Andreas Dreizler, Hermann Rottengruber
Abstract The fuel-independent particulate emissions of a direct injection gasoline engine were investigated. This was done by running the engine with reference gasoline at four different loads and then switching to hydrogen or methane port fuel operation and comparing the resulting particulate emissions and their size distribution. Differences in the combustion characteristics of hydrogen and gasoline were accounted for by diluting the inlet air with nitrogen and matching the pressure or heat release traces to those of gasoline operation. Methane operation is expected to generate particulate emissions lower by several orders of magnitude compared to gasoline and hydrogen does not contribute to carbon soot formation because of the lack of carbon atoms in the molecule. Thus, any remaining particulate emissions at hydrogen gas operation must arise from non fuel related sources, e.g. from lubrication oil, metal abrasion or inlet air.
2015-04-14
Journal Article
2015-01-1077
Huzeifa Badshah, Imad A. Khalek
As a part of an undergraduate honor thesis project, we measured real time solid particle number and size distributions emitted from various vehicle technologies during engine start-up. Also, for a limited number of vehicles, we measured real time metallic ash particle number. A total of 85 vehicles were tested ranging from modern diesel with diesel particulate filters (DPF) to modern gasoline port fuel injected (PFI) and gasoline direct injected (GDI) engines. The testing was done at the University of Texas in San Antonio (UTSA) and at Southwest Research Institute (SwRI) parking lots. The participants were UTSA students and faculty volunteers and SwRI volunteers. For post 2007 vehicles, the work showed that diesel engines equipped with filters have significantly less particles in engine exhaust compared to gasoline PFI and especially GDI during engine start-up.
2015-04-14
Journal Article
2015-01-1071
Qi Jiao, Rolf D. Reitz
Abstract Due to the upcoming regulations for particulate matter (PM) emissions from GDI engines, a computational fluid dynamic (CFD) modeling study to predict soot emissions (both mass and solid particle number) from gasoline direct injection (GDI) engines was undertaken to provide insights on how and why soot emissions are formed from GDI engines. In this way, better methods may be developed to control or reduce PM emissions from GDI engines. In this paper, the influence of engine operating parameters was examined for a side-mounted fuel injector configuration in a direct-injection spark-ignition (DISI) engine. The present models are able to reasonably predict the influences of the variables of interest compared to available experimental data or literature. For a late injection strategy, effects of the fuel composition, and spray cone angle were investigated with a single-hole injector.
2015-04-14
Journal Article
2015-01-1063
Yi Liu, Changsheng Su, James Clerc, Arvind Harinath, Leigh Rogoski
One field-returned DPF loaded with high amount of ash is examined using experimental and modeling approaches. The ash-related design factors are collected by coupling the inspection results from terahertz spectroscopy with a calibrated DPF model. The obtained ash packaging density, ash layer permeability and ash distribution profile are then used in the simulation to assess the ash impact on DPF backpressure and regeneration behaviors. The following features have been observed during the simulation: 1. The ash packaging density, ash layer permeability and ash distribution profile should be collected at the same time to ensure the accurate prediction of ash impact on DPF backpressure. Missing one ash property could mislead the measurement of other two parameters and thus affects the DPF backpressure estimation. 2. The ash buidup would gradually increase the frequency for the backpressure-based active soot regeneration.
2015-04-14
Journal Article
2015-01-1253
Konstantinos Siokos, Rohit Koli, Robert Prucka, Jason Schwanke, Julia Miersch
Increasingly stringent fuel economy and emission regulations require extension of engine displacement downsizing limits in order to maximize the efficiency benefits. Exhaust Gas Recirculation (EGR) proves to be one of the most promising solutions that will enable higher penetration of heavily downsized turbocharged gasoline engines into the market. More specifically, Low Pressure EGR is gaining support in the automotive industry over the High Pressure configuration since it interferes less with turbocharger efficiency. In this paper, Low Pressure (LP) cooled EGR is evaluated on a turbocharged direct-injection gasoline engine with variable valve timing using both simulation and experimental results. First, a model-based calibration study is conducted using simulation tools to identify fuel efficiency gains and provide the optimized actuator maps for part-load operation of the engine.
2015-04-14
Journal Article
2015-01-1257
David B. Roth, Iago Gonzalez Tabares, Anxo Sotelo Álvarez
Cooled LPL EGR is a proven means of improving the efficiency of a Gasoline Turbocharged Direct-Injection engine. One of the most significant hurdles to overcome in implementing a LPL EGR system is dealing with condensation of water near the entrance of the turbocharger’s compressor wheel. This is because the junction upstream of the compressor wheel where the fresh air and exhaust gas mix is the most favorable point in the system for condensation. A gasoline engine, and to a greater extent a spark ignition engine running on Natural Gas, will encounter enough water condensation at some steady-state conditions to quickly damage the compressor wheel due to the high-speed collision between the compressor blades and the water droplets. These conditions are a function of ambient temperature and humidity as well as the engine speed and load and EGR rate.
2015-04-14
Journal Article
2015-01-1244
Luigi Teodosio, Vincenzo De Bellis, Fabio Bozza
It is well known that the downsizing allows to improve the brake specific fuel consumption (BSFC) at part load operations for the spark ignition engines. On the other hand, the BSFC is penalized at high/full load operations because of the knock occurrence and of some limitations for the turbine inlet temperature. In fact, these drawbacks obligate to adopt a late phasing of the combustion process and an enrichment of air/fuel mixture, with a substantial detriment of the fuel economy. In this work, a downsized twin-cylinders turbocharged engine is analyzed by means of a 1D numerical approach. In a first stage, the 1D engine model is tuned against the experimental data at full load operations. A refined knock model is proposed, that is based on a detailed description of the chemical kinetics in the “end gas”. The model is validated through the identification of the knock-limited spark advance, denoting a very satisfactory agreement with the experimentally-identified spark timing.
2015-04-14
Journal Article
2015-01-1654
Billy G. Holland, Thomas L. McKinley, Bill R. Storkman
Cooled EGR continues to be a key technology to meet emission regulations, with EGR coolers performing a critical role in the EGR system. Designing EGR coolers that reliably manage thermal loads is a challenge with thermal fatigue being a top concern. The ability to estimate EGR cooler thermal fatigue life early in the product design and validation cycle allows for robust designs that meet engine component reliability requirements and customer expectations. This paper describes a process to create an EGR cooler thermal fatigue life model. Components which make up the EGR cooler have differing thermal responses, consequently conjugate transient CFD must be used to accurately model metal temperatures during heating and cooling cycles. Those metal temperatures are then imported into FEA software for structural analysis. Results from both the CFD and FEA are then used in a simplified numerical model to estimate the virtual strain of the EGR cooler.
2015-04-14
Journal Article
2015-01-1620
Feilong Liu, Jeffrey Pfeiffer
Low Pressure Cooled EGR (LPC EGR) brings a significant fuel economy and knock suppression benefit to modern boosted downsized spark ignition engine. As prerequisite to design an engine control system for LPC EGR, this paper presents a development of a set of estimation algorithms to accurately estimate the flow rate, pressure states and thermal states of the LPC EGR related conponents. Also, as LPC EGR becomes tightly integrated with other part of engine management system, this paper also presents experimental result focusing on the characterization of the impact of LPC EGR on engine torque control and exhaust component temperature estimation.
2015-04-14
Journal Article
2015-01-1635
Zhen Zhang, Stephan Stadlbauer, Harald Waschl, Richard Fuerhapter, Luigi del Re
At the moment, no equipment is available for fast measurements of particulate matter (PM) from production CI engines, especially during transients. Against this background, virtual sensors may be an option, provided their precision can be validated. This paper presents a new approach to estimate PM emission based only on in-cylinder pressure data. To this end, an in-cylinder pressure trace is measured with a high resolution (0.5 CAD) and every trace is divided into 8 segments according to critical cylinder events (e.g. opening of the valves or the beginning of injection). A piecewise principle component analysis (PCA) is used to compress the information. This information is then used for PM estimation via a second order polynomial model structure. The key element is the separate use of pressure trace information before and during the early stages of combustion. The model is parameterized by steady points and transient experiments which include parts of the FTP and the NEDC.
2015-04-14
Journal Article
2015-01-1690
Cristina Arnal, Yolanda Bravo, Carmen Larrosa, Valentina Gargiulo, Michela Alfè, Anna Ciajolo, María Ujué Alzueta, Ángela Millera, Rafael Bilbao
Soot fouling on Exhaust Gas Recirculation coolers (EGRc) decreases thermal efficiency, implying the unfulfillment of NOx standards, and increases the pressure drop producing the malfunctioning of this device. The characterization of soot is of great interest since soot chemical-physical properties may have a direct influence on the degree of malfunctioning of EGRc. Thus, the combined analysis and interpretation of all the soot chemical-physical features are essential to correctly interpret its behavior when soot is deposited on the EGRc walls. In this context, the aim of this study is the characterization of five different types of diesel soot (DS) which were collected from several high pressure EGRc, working at different conditions (engine bench and vehicle). Each soot sample was characterized by means of FTIR, specific surface area (BET method), elemental analysis, TGA, GC-MS. Besides, some of the carbon samples were also characterized by FESEM, TEM, XRD and Raman spectroscopy.
2015-04-14
Journal Article
2015-01-1040
Harsha K. Nanjundaswamy, Joel Deussen, Roger Van Sickle, Dean Tomazic, Tamas Szailer, Michael Franke, Matthias Kotter, Thomas Koerfer
Abstract Upcoming motor vehicle emission regulations, such as California's LEVIII, continue to tighten emission limitations in diesel vehicles. These increasingly challenging emission requirements will be met by improving the combustion process (reducing engine-out emissions), as well as improving the exhaust gas aftertreatment efficiency. Furthermore, intricate On-Board Diagnostics (OBD) systems are required to properly diagnose and meet OBD regulation requirements for complex aftertreatment systems. Under these conditions, current monitoring strategies are unable to guarantee reliable detection of partially failed systems. Additionally, new OBD regulations require aftertreatment systems to be diagnosed as a whole. This paper covers potential OBD strategies for LEVIII aftertreatment concepts with regard to regulation compliance and robustness, while striving to use existing sensor concepts.
2015-04-14
Journal Article
2015-01-1034
Homayoun Ahari, Michael Smith, Michael Zammit, Kenneth Price, Jason Jacques, Thomas Pauly, Lin Wang
Significant reduction in Nitrogen Oxide (NOx) emissions will be required to meet LEV III/Tier III Emissions Standards for Light Duty Diesel (LDD) passenger vehicles. As such, Original Equipment Manufacturers (OEMs) are exploring all possible aftertreatment options to find the best balance between performance, durability and cost. The primary technology adopted by OEMs in North America to achieve low NOx levels is Selective Catalytic Reduction (SCR). The critical parameters needed for SCR to work properly are: an appropriate reductant such as ammonia (NH3) provided as Diesel Exhaust Fluid (DEF), which is an aqueous urea solution 32.5% concentration in weight with water (CO(NH2)2 + H2O), optimum operating temperatures, and optimum nitrogen dioxide (NO2) to NOx ratios (NO2/NOx). The NO2/NOx ratio is most influenced by Precious Group Metals (PGM) containing catalysts upstream of the SCR catalyst.
2015-04-14
Journal Article
2015-01-1746
Hassan Karaky, Gilles Mauviot, Xavier Tauzia, Alain Maiboom
Reducing NOx tailpipe emissions is one of the major challenges when developing automotive Diesel engines, which must simultaneously face stricter emission norms and reduce their fuel consumption/CO2 emission. In fact, the engine control system has to manage at the same time the multiple advanced combustion technologies such as high EGR rates, new injection strategies, complex after-treatment devices and sophisticated turbocharging systems implemented in recent diesel engines. In order to limit both cost and duration of engine control system development, a virtual engine simulator has been developed in the last few years. The platform of this simulator is based on a 0D/1D approach, chosen for its low computational time. The existing simulation tools lead to satisfactory results concerning the combustion phase as well as the air supply system. In this context, the current paper describes the development of a new NOx emission model which is coupled with the combustion model.
2015-04-14
Technical Paper
2015-01-0776
Gerben Doornbos, Stina Hemdal, Daniel Dahl
This paper investigates how the rate of dilution applied can be extended while maintaining normal engine operation. Adding combustion residuals or additional air to a stoichiometric air fuel mixture creates advantages for an otto engine. The lower combustion temperature and higher theoretical efficiency results in reduced fuel consumption and decreased NOx formation. However dilution negatively affects the ignite-ability of the mixture and decreases the flame speed, possibly resulting in misfires and partial burns. Therefore a Volvo four-cylinder was equipped with a dual coil ignition system. This system made it possible to extend the ignition duration and vary the ignition current. Furthermore a sweep was performed in valve timing and type of dilution, air or combustion residuals. While maintaining a CoV < 5% the dual coil ignition system was able to extend the maximum lambda value by 10 to 15% depending on the load point.
2015-04-14
Technical Paper
2015-01-0836
Behzad Rohani, Stephen Sungsan Park, Choongsik Bae
Low Temperature Combustion (LTC) is feasible only in lower load ranges so for the real world application of LTC, engine operation mode should frequently change back and forth from LTC mode in lower loads to conventional mode in higher loads. In this research, effect of injection strategy on smoothness and emissions of mode transition in a single cylinder heavy duty diesel engine is studied. The Exhaust Gas Recirculation (EGR) line was controlled by a servo-valve capable of opening or closing the EGR loop during only one engine cycle. Ten cycles after the EGR valve closure were taken as the transition period during which injection timing and quantity were shifted in various ways (i.e. injection strategies) and the effect on Indicated Mean Effective Pressure (IMEP) stability and emissions was studied.
2015-04-14
Journal Article
2015-01-0255
Claudia Meis, Stefan Mueller, Stephan Rohr, Matthias Kerler, Markus Lienkamp
Abstract Battery aging in electric and hybrid vehicles is a major issue, and one which has to be taken into consideration during all stages of the vehicle lifecycle. It depends on many factors, such as the cell chemistry, the cell design and stress factors as well as the current rate, ΔDOD and temperature. The stress factors have been identified as being crucial due to their influence on two important battery parameters: capacity and inner resistance. Battery aging models are essential to describing the interacting influences that stress factors have on battery parameters. They provide insights about battery aging without the need for extensive measurements. Various battery aging models with widely varying capabilities are described in the literature. The aim of this paper is to provide a decision guide for utilizing the most appropriate aging model for the major stages of the vehicle lifecycle: vehicle development, operation (onboard and offboard) and post-operation.
2015-04-14
Journal Article
2015-01-1145
Darrell Robinette, Daniel Wehrwein
This investigation utilizes energy analysis and statistical methods to optimize the design parameters of an automatic transmission and assess fuel consumption performance with a prescribed amount of variation in parasitic loss. A generalized factorial experiment is undertaken to determine the optimal combination of transmission design parameters for fuel consumption and acceleration performance across widely varying vehicle platforms and engine types. The design parameters considered are the number of fixed gear ratios, launch gear ratio, top gear ratio and ratio step size progression. For a single vehicle platform with multiple engines and the optimized transmission as determined from the generalized factorial experiment, a Monte Carlo simulation was used to explore the range of fuel consumption to be expected for multiple distributions of parasitic losses that could be typical of various production tolerances.
2015-04-14
Journal Article
2015-01-0984
Yang Zheng, Mengmeng Li, Michael Harold, Dan Luss
Abstract Current NOx emission reduction systems, selective catalytic reduction (SCR) and NOx storage and reduction (NSR), function well after achieving their operation temperature (typically ca. 250 °C) but have unsatisfactory NOx conversion at lower exhaust temperatures encountered during cold start and low load operation. The reduced exhaust temperature of advanced diesel engines with higher fuel efficiency challenges the low-T NOx reduction. We report here a new concept of high low-T deNOx efficiency of up to 80% at a feed temperature of ca. 200 °C at relevant space velocities (70k h−1). It utilizes high-frequency hydrocarbon pulsing on a dual-layer LNT-SCR monolithic catalyst under lean conditions. This system has the potential to expand the operating temperature window of the conventional deNOx devices.
2015-04-14
Journal Article
2015-01-0986
Dieter Rauch, David Kubinski, Giovanni Cavataio, Devesh Upadhyay, Ralf Moos
Abstract Ammonia adsorption on the catalyst surface is a crucial step in the selective catalytic reduction of nitrogen oxides over zeolites with NH3 as the reducing agent. In this study, two small pore zeolites with chabazite frameworks, H-SSZ-13 and Cu exchanged SSZ-13, are examined. Adsorption of NH3 on the zeolite causes changing electrical properties of the material. They can be detected by a radio frequency based technique. We have found that with this method it is possible to determine the amount of adsorbed NH3 on these catalysts, examining both the influences of temperature and NH3/NO feed gas ratio. At constant temperature, a fairly linear correlation between the resonance frequency and the amount of adsorbed ammonia was observed. Furthermore, this method also allows differentiation between some of the NH3 adsorption sites.
2015-04-14
Journal Article
2015-01-1085
Marc C. Besch, Joshua Israel, Arvind Thiruvengadam, Hemanth Kappanna, Daniel Carder
Abstract This study was aimed at experimentally investigating the impact of diesel/natural gas (NG) dual-fuel retrofitting onto gaseous emissions emitted by i) legacy, model year (MY) 2005 heavy-duty engines with cooled EGR and no after-treatment system, and ii) a latest technology engine equipped with DPF and urea-SCR after-treatment systems that is compliant with 2010 US-EPA emissions standards. In particular, two different dual-fuel conversion kits were evaluated in this study with pure methane (CH4) being used as surrogate for natural gas. Experiments were conducted on an engine dynamometer over a 13-mode steady-state test cycle as well as the transient FTP required for engine certification while gaseous emissions were sampled through a CVS system. Tailpipe NOx emissions were observed at a comparable level for diesel and diesel/CH4 dual-fuel operation for the 2010 compliant engine downstream the SCR.
2015-04-14
Technical Paper
2015-01-1688
Eric Wood, Jeremy S. Neubauer, Evan Burton
With support from the Vehicle Technologies Office in the U.S. Department of Energy, the National Renewable Energy Laboratory (NREL) has developed BLAST-V—the Battery Lifetime Analysis and Simulation Tool for Vehicles. The addition of high resolution spatial-temporal travel histories has enabled BLAST-V to investigate user-defined infrastructure rollouts of publically accessible charging infrastructure, as well as quantify impacts on vehicle and station owners in terms of improved vehicle utility and station throughput. This paper will present simulation outputs from BLAST-V quantifying the utility improvements of multiple distinct rollouts of publically available level 2 electric vehicle service equipment (EVSE) in the Seattle metropolitan area. Publically available data on existing level 2 EVSE will also be used as an input to BLAST-V with resulting vehicle utility compared to a number of mock rollout scenarios.
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
Journal Article
2015-01-0809
Joonsik Hwang, Yongjin Jung, Choongsik Bae
The effect of biodiesel produced from waste cooking oil (WCO) on the soot particles of a compression ignition diesel engine was experimentally investigated and compared with conventional diesel fuel. The indicated mean effective pressure of approximately 0.75 MPa was tested under an engine speed of 1200 revolutions per minute. The fuels were injected at an injection timing of -5 crank angle degree after top dead center with injection pressures of 80 MPa. Detailed characteristics of particulate matters were analyzed in terms of transmission electron microscopy (TEM), thermogravimetric analysis and elemental analysis. For the work, soot aggregates were collected with a thermophoretic sampling device installed in the exhaust pipe of the engine. High-resolution TEM images revealed that the WCO biodiesel soot was composed of smaller primary particle than diesel soot. The mean primary particle diameter was measured as 19.9 nm for WCO biodiesel and 23.7 nm for diesel, respectively.
2015-04-14
Journal Article
2015-01-0810
Hao-ye Liu, Zhi Wang, Jian-Xin Wang
Wide Distillation Fuel (WDF) refers to the fuels with a distillation range from initial boiling point (IBP) of gasoline to final boiling point (FBP) of diesel. Polyoxymethylene dimethyl ethers (PODEn) have high oxygen content and cetane number, are promising green additive to diesel fuel. In this paper, WDF was prepared by blending diesel and gasoline at ratio of 50/50, by volume; the mass distribution of oligomers in the PODEn product was 0.27% of n=1, 2.553% of n=2, 88.9% of n=3 and 8.46% of n=4, by volume. Neat diesel fuel (D), WDF, WDF (90%)-PODEn (10%) (P10), WDF (80%)-PODEn (20%) (P20) and WDF (70%)-PODEn (30%) (P30) were tested in a light-duty single-cylinder diesel engine, combustion characteristic, fuel consumption and exhaust emissions were measured. The results showed that: adding PODEn into WDF reduces the ignition delay of blend fuels, so fuel-air mixing is not sufficient compared neat WDF.
2015-04-14
Journal Article
2015-01-0892
Alastair Smith, Rod Williams
The formation of deposits within injector nozzle holes of common-rail injection fuel systems fitted to modern diesel cars can reduce and disrupt the flow of fuel into the combustion chamber. This can lead to a reduction in power output because of reduced or less efficient combustion; hence there is a great deal of interest in studying these deposits with the ultimate aim of controlling them. Through previous experimentation [1], a chassis dynamometer test method was developed which combined high fouling operating conditions with zinc doped fuels to give measureable and repeatable fouling rates within a 36 hour test, whilst remaining representative of real world driving by incorporating >50% of the test drive cycle at typical motorway road loads.
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