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Viewing 1 to 30 of 101935
Technical Paper
2015-01-01
Susan Sawyer-Beaulieu, Edwin K.L. Tam
Life-cycle assessments (LCAs) conducted, to date, of the end-of-life phase of vehicles rely significantly on assumed values and extrapolations within models. The end phase of vehicles, however, has become all the more important as a consequence of increasing regulatory requirements on materials recovery, tightening disposal restrictions, and the rapid introduction of new materials and electronics, all potentially impacting a vehicle’s efficacy for achieving greater levels of sustainability. This article presents and discusses selected research results of a comprehensive gate-to-gate life-cycle-inventory (LCI) of end-of-life vehicle (ELV) dismantling and shredding processes, constructed through a comprehensive and detailed case study, and argues that managing and implementing creative dismantling practices can improve significantly the recovery of both reusable and recyclable materials from end-of-life vehicles. Although the amount of parts and materials recovered and directed for reuse, remanufacturing or recycling may be as much as 11.6% by weight of the ELVs entering a dismantling process [1], greater rates of reuse and/or recycling may be achieved by the strategic management of the ELVs entering the dismantling process according to age.
Technical Paper
2014-10-13
Shuonan Xu, David Anderson, Amrit Singh, Mark Hoffman, Robert Prucka, Zoran Filipi
The looming shortage of crude oil provides impetus for engineers to use alternative gaseous fuels in existing engines. Dual-fuel natural gas engines preserve diesel thermal efficiencies and reduce fuel cost without imposing consumer range anxiety. Increased complexity poses several challenges, including the transient response of an engine with direct injection of diesel fuel and injection of Compressed Natural Gas (CNG) upstream of the intake manifold. A 1-D simulation model of a Cummins ISX heavy duty, dual-fuel, natural gas-diesel engine modeled in the GT-Power environment is developed to study and improve transient response. The simulated VGT behavior, intake and exhaust geometry, valve timings and injector models are validated through experimental results. A triple Wiebe combustion model is applied to characterize experimental combustion results for both diesel and dual-fuel operation. The ignition delay and injection timing are determined through an iterative calculation based on Start of Combustion (SOC) and a predictive ignition delay correlation.
Technical Paper
2014-10-13
Prasanth Balasubramanian, Bharathan Sivashanmugham
This paper presents the air intake system model for turbocharged diesel engine with EGR. The individual models of intake system components and EGR were assembled to develop a global air intake system. The model monitors the pressure, temperature and air flow rate at various levels in the intake system and predicts the volumetric efficiency of engine and pumping losses in the valves. The validation of the developed model is done by correlating the simulated results with the experimental results. The model showed a good agreement with measurements for both steady state and transient conditions. The validated model is used run a DOE following robust engineering approach (Taguchi method) and the results were analyzed. This approach enabled reduction of the variation of the air intake temperature that is inducted by the cylinders upon wide range of ambient conditions and EGR flow rates. The model is then used to optimize the intake system to reduce the pressure fluctuations and improve the volumetric efficiency of the cylinders.
Technical Paper
2014-10-13
Tao Yin, Tie Li, Longhua Chen, Bin Zheng, Fei Zhao
Worldwide demands for better fuel economy and less pollutant emissions of automobiles are driving vehicle manufactures to seek further technical improvements in reciprocating engines. Spark ignited (SI) engines have a significant optimization potential by techniques such as supercharging, variable valve timing, downsizing, exhaust gas recirculation or direct injection. Each method distinctively influences the engine performance in variable operating conditions, which makes it complex to apply these techniques in a synergy pattern. Therefore, optimization of engine parameters is expected to make full use of the positive coupling techniques.This paper studies the effect of cooled EGR on fuel consumption and anti-knock performance of a boosted port fuel injection (PFI) SI engine. Experimental results show that the cooled EGR increases the thermal efficiency by 2%~18% depending on the operation conditions. Compared to low load operations, more improvements of the thermal efficiency are obtained at higher loads, primarily owing to the enhanced anti-knock performance, advanced combustion phasing, elimination of fuel-rich operations as well as reduced heat transfer loss with cooled EGR.
Technical Paper
2014-10-13
A.F. Khan, A.A. Burluka, Dave OudeNijeweme, Jens Neumeister, John Mitcalf, Paul Freeland
A holistic modelling approach has been employed to predict combustion, cyclic variability and knock propensity of a high power density SI engine fuelled with gasoline. A quasi-dimensional, thermodynamic combustion modelling approach has been coupled with realistic chemical kinetics modelling of autoignition using reduced mechanisms for gasoline surrogates. The quasi-dimensional approach has been found to allow a fast and appreciably accurate prediction of the effects of operating conditions on the engine performance. It has also provided an insight in to the stability of the turbulent flame as the engine load and speed is varied. The cyclic variability was modelled by perturbing the in-cylinder turbulence and charge composition according to a Gaussian distribution. Its coupling with autoignition modelling allowed to elucidate the effects of operating conditions such as spark-timing and charge temperature on the autoignition onset. In this approach, the autoignition propensity has been predicted for the entire spectrum of cyclic variations in cylinder pressure.
Technical Paper
2014-10-13
Hiroshi Tashima, Daisuke Tsuru
The discrete multi-component model for residual heavy fuel oil (HFO), developed by Goldsworthy et al. in the mid-2000s, proved to be a simple but practical approximation to reproduce the combustion process of HFO spray on a couple of CFD simulation codes. It succeeded in providing qualitative explanation about the spray and flame progression of HFO inside a visual constant-volume combustion chamber. Struckmeier et al. developed their two-component HFO model, which virtually separates every spray droplet into two smaller droplets of each component to predict their evaporation process. They showed good agreement with the visualization results on the various HFO spray behaviour in the same combustion chamber. However, all the above examinations were done only qualitatively not quantitatively since the heat release in the chamber of large internal volume was difficult to detect accurately. In this study, the FIA vessel of much smaller volume was newly introduced in order to evaluate the heat release process of HFOs with good or poor fuel properties.
Technical Paper
2014-10-13
Yongqiang Han, Jianjian Kang, Xianfeng Wang, Yang Chen, Zhichao Hu
Energy saving and environment protection has been two major subjects in the development of automobile industry. In the internal combustion engine, about 40% of fuel energy is released into the atmosphere through waste gas. The recovery and utilization of the heat from waste gas can realize the goals of energy saving and cost reducing. In fieldof waste heat recovery, the organic Rankine cycle (ORC) has good prospects and has been widely used.Turbo has been selected firstly as the expander in traditional ORC. However, turbo has disadvantages of high manufacturing cost and narrow applicable range. In this paper, a new organic Rankinecycle coupling free piston (ORC-FP) system used in theinternal combustion engine (ICE) exhaust heatrecovery is proposed and its working principle is introduced in detail.In this system, the free piston with constant force outputfunctions as expander in ORC and operates reciprocally to output workunder the driven of working fluid R245ca,which absorbs heat from waste gas and provides vapor power.
Technical Paper
2014-10-13
Abdelouahad AIT MSAAD, Mustapha MAHDAOUI, Elhoussin AFFAD, mhamed mouqallid
The simulation of combustion in internal combustion engines (ICE) is very important for an accurate prediction of engine performance and pollutant formation. These engines simulation help to gain a better understanding of the coupling between the various physical and chemical processes. The objective of the present paper is to study turbulent combustion in IC engine. A lagrangian eulerian model coupled with presumed pdf is used to study the problems of chemical kinetics and the k-ε model is used for the modeling of the turbulence. We got the reduced mechanism through the reduction of detailed mechanism of the methane (GRI 3.0) combustion by using the Principal Component Analyses (PCAF). It is considered the first point for the application of the Computational Singular Perturbation method (CSP). We used this method (CSP) to reduce the detailed mechanism of the methane already reduced by PCAF to a mechanism containing 9-STEP. The validation of this reduced mechanism has been made by the comparison between the results of reduced and detailed mechanism of methane GRI 3.0; for major species, pollutants species and temperature at high pressure and lean mixture.
Technical Paper
2014-10-13
Mohammed Reza Kianifar, Ioan Campean, Tim Beattie, David Richardson
In addition to the pressure to reduce CO2 emissions, the expected introduction of new emission legislation focused on particulate number emissions (Pn) adds considerable challenge to the Gasoline Direct Injection (GDI) engine calibration task, in order to avoid an increase in complexity and cost of the aftertreatment system. The research presented in this paper focuses on the development of a calibration optimisation methodology aiming to deliver an enhanced trade-off between high level attributes such as the CO2 and Pn emissions and drive-ability, for a GDI engine with multiple injection ECU capability. The work is based on steady state engine test experiments conducted in the Powertrain Research Centre at the University of Bradford. The paper describes the engine mapping experiments which were based on an innovative sequential space-filling DoE test plan. This is underpinned by a space filling screening experiment aimed to explore efficiently the variable space and study the effect of the calibration variables on Pn and CO2, followed by mapping experiments consisting of iterative model building – model validation DoEs based on optimal space filling criteria.
Technical Paper
2014-10-13
Mohammed Reza Kianifar, Ioan Campean, David Richardson
The development of engines to achieve improved performance, fuel consumption, emissions and drivability, in response to the demands of the market and the requirements of legislation, and within reduced development times, is an increasing challenge. To meet this challenge an increasing number of control devices, such as variable valve timing, are being introduced all of which require additional calibration requirements for the engine electronic control unit (ECU). These technologies ease the task of achieving targets for emissions and fuel economy. However, they increase the complexity in the powertrain development process due to increasing development time and the cost of testing the engine at different settings of input variables. This paper presents the development of a multidisciplinary design optimisation framework to study the camshaft control strategies for a Gasoline Direct Injection (GDI) engine equipped with Variable Camshaft Timing (VCT). The aim of this research is to investigate the advantages of camshaft control strategies for the GDI engine considering the trade-off between technology improvement and cost effectiveness.
Technical Paper
2014-10-13
Krisada Wannatong, Sompach Kongviwattanakul, Thanadech Priroon, Thananchai Tepimonrat, Orawan Wattanapanichaporn
End of line test (EOL) of engine control units (ECU) is the process of ECU functions validation before releasing ECUs to the car assembly process. Examples of ECU function that need to be validated are idle control, air path control and faults manager function. To perform EOL, a vehicle and a chassis dynamometer are used to enable control functions validation inside the ECU. However, this poses high operating cost and long setup time. This paper presents the development of Hardware-in-the-Loop (HiL) system, which imitates real vehicle behavior on a chassis dynamometer. The engine model was developed using AVL Boost RT software, an engine cycle simulation modeling approach. The vehicle model is developed using AVL CRUISE software. In order to interface the engine and vehicle models with the ECU, HiL system is implemented. In the new EOL process, the vehicle is operated following the extra urban driving cycle (EUDC) including short engine idling time. During the test, the control and safety functions check are performed.
Technical Paper
2014-10-13
Florian Kleiner, Christina Artmann, Hans-Peter Rabl
In coming years a special focus in the field of gasoline engines will be on downsized concepts and highly-charged gasoline direct injection engines. These represent the result of stricter emission laws, higher customer requirements, greater environmental awareness as well as high demands on materials and resources. Especially at cold start and the warm-up operation GDI engines have an issue with oil dilution. Fuel gets into the oil pan and is mixed with the engine oil so that the physical and chemical properties of the engine oil are changed. With the adjustment of the engine operating points to higher mean effective pressures resulting in downsizing concepts also an additional increase of the fuel entry into the engine oil occurs. At the University of Applied Sciences Regensburg measurements were carried out at a direct injected gasoline engine with side located injector position. This engine with 1.8 l displacement disposes e.g. a Common-Rail Injection system up to 20 MPa, a variable camshaft regulation and a variable tumble system.
Technical Paper
2014-10-13
Dhaminda Hewavitarane, Sadami Yoshiyama, Hisashi Wadahama, Xin Li
Authors: Mr Dhaminda Hewavitarane (The University of Kitakyushu, Japan), Dr Sadami Yoshiyama (The University of Kitakyushu, Japan) , Mr Hisashi Wadahama (The University of Kitakyushu, Japan). Postal Address: The University of Kitakyushu, 1-1 Hibikino, Wakamatsu-ku, Kitakyushu City, Fukuoka Prefecture, 808-0135. Japan. Phone/Fax: (TEL)+81906953215, (MOBILE): +819036658310, (FAX)+81936953315 e-mail: hewavitarane_d@hotmail.com, yoshiyama@kitakyu-u.ac.jp Abstract: Background: In our modern industrial civilization, the vast majority of mechanical work is produced by heat engines. While the efficiency of heat engines has improved over the years, they remain relatively inefficient, loosing a significant portion of the input heat as waste heat. Waste heat recovery as a means of improving the overall efficiency of these engines in automotive applications has gained momentum in recent years. While many waste heat recovery (W.H.R) systems have been proposed and tested, the balance between, their efficiency, package size, integrability to the drive train and most importantly cost, have made most nonviable.
Technical Paper
2014-10-13
Karthikeyan N, Anish Gokhale, Narendra Bansode
In scooters, the Continuously Variable Transmission(CVT) is used to transmit the power from the engine to the wheels. The CVT transmission consists of a two pulleys connected to each other through a belt . The change in the transmission ratio is achieved due to the change in the pulley diameters. A centrifugal clutch is attached to the rear pulley to transmit the power to wheels once the engaging engine speed is reached. The heat is generated due to the belt slippage and the engagement of the centrifugal clutch. Excessive heating may damage the belt ,clutch and deteriorate its performance. The cooling of the belt , pulleys and the clutch is thus important for its safe operation. The cooling is achieved by the centrifugal cooling fan which forces the air over the belt, pulley and clutch. A clear understanding of the cooling system is important in designing the air flow path for clutch cooling of CVT housing. The efficiency of the cooling system depends on the quantity and direction of flow .
Technical Paper
2014-10-13
Le-zhong Fu, Zhijun Wu, Liguang Li, Xiao Yu
Internal combustion rankine cycle engine could have high fuel efficiency and ultra-low emission performance. In an ideal ICRC engine, high temperature liquid water is injected into the cylinder near top dead center to control the combustion temperature and cylinder pressure rise rate, and then enhances the thermo efficiency and work. The reason is the extra work fluid into the cylinder in the form of water vapor which can make use of the combustion heat more effectively. Moreover, the high temperature water can be heated up through heat exchanger by exhaust gas and engine cooling system, and the waste heat carried away by engine cooling system and exhaust gas can be recovered and utilized. In this paper, a retrofitted, single-cylinder, air-cooled SI engine with propane fuel is adopted in the test. To simplify the experiments preparation, water is heated up in an electric heater in a high-pressure rail and injected into the cylinder with a solenoid diesel injector. The water injection pressure is obtained from a N2 tank and amplified through the pressure amplifier up to 15~25MPa.
Technical Paper
2014-10-13
Guillaume Pilla, Loic Francqueville
Reduction of CO2 emissions is becoming one of the great challenges for future gasoline engines. Downsizing is one of the most promising strategy to achieve this reduction, though it facilitates knock phenomena. Therefore downsizing has to be associated with knock limiting technologies such as increased aerodynamics, dilution and thermal measures. High dilution levels allow to push back the knocking limit thus enhancing engine efficiency. The maximum gain of efficiency is therefore closely dependent on the dilution limit. State of the art shows that combustion initiation can be critical for highly diluted mixture combustion. If spark ignition systems are commonly used in GDI engines, they have known few evolutions since their invention. By optimizing key parameters such as spark duration, energy or size, it can be expected significant gain in dilution acceptance on GDI engines. This paper presents the results of innovative ignition systems tests on the dilution acceptance of a 400cc optical GDI engine.
Technical Paper
2014-10-13
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. The eccentricity is easily adjustable. The first full scale engine demonstration test runs were made in Oulu University engine laboratory. The first test are explained. The first demonstration version is modified from an existing commercial SI engine. A GT-Power simulation model of the engine is made. The benefits of the new crank mechanism are demonstrated by the help of the simulation model. The new mechanism offers great possibilities for ex. to increase the part load performance in SI engines or make the engine adjustable for different fuels with best possible efficiency.
Technical Paper
2014-10-13
Zhengyang Ling, Alexey Burluka, Ulugbek Azimov
Replacing the conventional fossil fuel totally or partially with alcohols or ethers in SI engine is a promising way to reduce pollutant emissions. Alcohols are more promising than other alternatives such as hydrogen because they are compatible with existing fueling distribution infrastructure and are easily stored in a vehicle. Besides, they can be blended with standard gasoline in arbitrary amounts, facilitating a gradual transition to renewable fuels. Alcohols also have a resistance to engine knock greater than gasoline owing to their high octane numbers. These advantages of alcohol-blends fuel have drawn a great attention to them, so that a large body of studies of alcohol-blends fuel in spark-ignition could be found in the literature. Nonetheless, investigations of knock properties of ether-containing blends are by far much less numerous, especially for modern boosted engines. Blending with either compounds may change the burning rate at high pressure, which consequently changes the anti-knock properties of these fuels and lead to a deterioration in the vehicle drivability.
Technical Paper
2014-10-13
Karel Steurs, Christopher Blomberg, Konstantinos Boulouchos
Knock is often the main limiting factor for brake efficiency in spark ignition engines and is mostly attributed to auto-ignition of the unburned mixture in front of the flame. The design of future engines would therefore benefit greatly of accurate models to predict the occurrence of knock. In order to study knock in a systematic way, experiments with ethanol and iso-octane have been carried out on a 250cc single cylinder spark ignition test engine with variable intake temperatures at wide open throttle and stoichiometric premixed fuel/air mixtures. At different speeds and intake temperatures spark angle sweeps have been performed ranging from late timing and non-knocking combustion up to early timing and strong knocking conditions. The in-cylinder pressure traces have been recorded for all operating points and are used to detect knocking conditions. A 1-D engine simulation model is used to calculate the heat release rates and burned-/unburned zone temperatures are computed. Special attention is given to the heat transfer in the cylinder and the intake port during the intake and compression strokes to accurately determine the temperature of the unburned mixture and the related sensitivities are explored.
Technical Paper
2014-10-13
Yuan Fang'en
Gasoline engine downsizing is firmly established as one of the main technologies for achieving fuel consumption and CO2 reduction targets, with increasing degrees of downsizing being applied in the market place. With advanced downsizing concepts a fuel consumption reduction of 30 % can be achieved. Gasoline Direct Injection (GDI), compared to port fuel injection, allows an increase of the compression ratio by approximately one unit. The main benefits of the spray-guided GDI combustion system are largely possible due to the injector location next to the spark plug. This allows more accurate air fuel mixture control within the combustion chamber and at the spark plug through the variation of injection timing. Further benefits are achievable when multiple injections are used. Spray-guided combustion systems can be used with both solenoid multi-hole and outward opening piezo injectors. Thus, the knock limit at full load can be improved, and it is also an enabler to run stratified lean. Based on that, this article investigated the effect of injection parameter on spray and combustion.
Technical Paper
2014-10-13
Cyrille Frottier, Marc Sens, Michael Rieß, Malte Wigger lng, Andreas Benz, Noriyuki Maekawa, Koji Onihsi, Kazuhiro Oryoji, Kenichi Machida
In the near future, emission standards legislation will become more and more restrictive for gasoline engines. Introduction of direct injection made the decrease of particulate number very challenging and many mechanical and physical features have been developed for reducing it on combustion and after-treatment side. IAV GmbH, Hitachi Automotive Systems Europe GmbH and Hitachi Automotive Systems, Ltd. cooperated for combustion enhancement by using Hitachi components dedicated to high pressure injection. This paper will focus on this new high pressure fuel system improving droplets atomization and consequently combustion efficiency. Hitachi system includes a fuel pump and injectors operating up to 30 MPa. New spray patterns have been designed in CFD (Computational Fluid Dynamics) simulation for a specific engine (boosted engine with 1.4L and direct injection). Those have been designed at IAV GmbH keeping a compact spray pattern and a reduced spray penetration. Then, the injectors have been manufactured by Hitachi Automotive Systems, Ltd. with an additional feature avoiding any needle bouncing at high pressure injection.
Technical Paper
2014-10-13
Ben Leach, Richard Pearson, Rana Ali, John Williams
Engine downsizing is a key approach employed by many vehicle manufacturers to help meetfleet average CO2 emissions targets. With gasoline engines in particular reducing engine swept volume while increasing specific output via technologies such as turbocharging, direct injection (DI) and variable valve timing can significantly reduce frictional and pumping losses in engine operating areas commonly encounteredin legislative drive cycles. These engines have increased susceptibility to abnormal combustion phenomena such asknock due to the high brake mean effective pressures which they generate. This ultimately limits fuel efficiency benefits by demanding use of a lower geometric compression ratio and sub-optimal late combustion phasing at the higher specific loads experienced by the engines. The lower expansion ratio and retarded combustion in turn increase the exhaust gas temperature, which often leads to a need add extra fuel that cannot be fully combusted in order to cool and protect engine components from thermal damage.Optimising theengine design for use with a fuel with an increased research octane number (RON) allows the adoption of a higher compression ratio.
Technical Paper
2014-10-13
Yuhan Huang, Guang Hong, Ronghua Huang
Ethanol is a widely used alternative fuel to address the issue of sustainability. However, making the use of renewable fuel effective and efficient is still challenging. Ethanol direct injection plus gasoline port injection (EDI+GPI) has been in development due to its great potential in taking the advantages of ethanol fuel to increase the compression ratio and thermal efficiency. The work reported in this paper contributes to understanding the fuel and gas behaviours which are crucial in the development of EDI+GPI engine. A set of engine models have been developed using ANSYS FLUENT. The model was verified by comparing the numerical and experimental results of cylinder pressure in an engine and spray shapes in a constant volume chamber. The verified model was used to investigate the fuel vaporization and mixture formation of the EDI+GPI research engine. The effect of the ethanol/gasoline ratio on charge cooling has been studied. Compared with GPI only, EDI+GPI demonstrated stronger effect on charge cooling by decreased in-cylinder temperature and increased volumetric efficiency.
Technical Paper
2014-10-13
Ajabofu Augoye, Pavlos Aleiferis
International obligations to reduce CO2 emissions, as well as national requirements to strengthen security of fuel supply present the need for diversification towards use of sustainable reduced-carbon fuels such as alcohols. Of these alcohols, ethanol is currently the preferred option with superior octane rating and heat of evaporation compared to gasoline. Ethanol is also already used as a component in pump-grade gasoline of 5-10% per volume in many countries where specifications traditionally dictate the use of anhydrous ethanol (less than 1% water per volume) for such type of blending. This possesses certain challenges since ethanol production typically gives a final product of ethanol purity of about 95.5% per volume with the rest being largely water. Additionally, at higher than this ethanol purity level, ethanol and water exit as an azeotropic mixture. This requires a cost intensive method to further reduce the water content in the mixture to less than 4%. Considering this economics, interest in the use of hydrous ethanol as automobile fuel is rising.
Technical Paper
2014-10-13
Michael Storch, Lars Zigan, Michael Wensing, Stefan Will
For future CO2- reductions of spark ignition (SI) engines, the combination of modern engine operation concepts, e.g. direct injection (DI), and the use of biofuels such as ethanol is essential. However, DI concepts have the drawback of higher particulate matter emission as compared to port fuel injection. Especially when driven with biofuels, the operation of direct injection spark ignition engines (DISI) requires a deeper insight into particulate formation processes. Biofuel components show completely different fuel properties as compared to gasoline and lead to a very complex chain of effects in engine combustion. Therefore the effects of varying composition on mixture formation, combustion and soot formation can hardly be predicted. Previous studies report opposing results about using ethanol blended gasoline fuels for engine applications. Some describe increasing, while others state decreasing particulate emissions for higher ethanol contents in the fuel. The reason for these contradictory results is unclear and must be further addressed.
Technical Paper
2014-10-13
Martin Pechout, Ales Dittrich, Michal Vojtisek-Lom
One of the pathways to carbon-neutral, sustainable transportation and to decreasing dependency on petroleum is to find out drop-in alternative fuels for gasoline engines. In the general fleet, the usage of ethanol is limited to blend with relatively small concentrations due to large differences compared to gasoline. Compared to ethanol, butanol, which can be produced from non-food biomass, exhibits lower hygroscopicity and aggressivity, and has volumetric energy density closer to gasoline. This paper reports on the experimental combustion study, where an ordinary, unmodified port fuel injection gasoline engine was operated on blends of gasoline with various concentrations of two butanol isomers (n-butanol and iso-butanol) and on pure butanol. A naturally aspirated, three-cylinder, four-valves-per-cylinder, 1.2 dm3 Škoda 1.2 HTP engine has been tested at steady-state operating points on an engine dynamometer. The operating points were selected to cover both common and uncommon yet potentially problematic operating conditions.
Technical Paper
2014-10-13
Pierre Brequigny, Fabien Halter, Christine Rousselle, Bruno Moreau, Thomas Dubois
The current decrease in fossil energy resources requires a diversification of the liquid and gaseous fuels potentially consumable in internal combustion engines. The use of these fuels alters the combustion process and the heat released as well. In a Spark Ignition engine, the heat released is mainly piloted not only by the mixture reactivity but also by its sensitivity to stretch effects. Usually, the input parameter for CFD simulation is only the non stretched laminar combustion velocity. Former studies performed with different burner configurations have demonstrated a strong impact of stretch effects on the turbulent flame speed. Only few results can be found in the literature for SI engine configurations. The purposes of the present paper are first to evaluate stretch effects on the flame front propagation inside an optical SI-engine and to investigate the relative importance of these effects depending on the fuel considered. For this study, different fuels and mixture conditions presenting almost equivalent laminar flame speeds and thermo-dynamical properties have been selected.
Technical Paper
2014-10-13
Thomas Briggs, Terrence Alger, Barrett Mangold
A series of ignition systems were evaluated for their suitability for high-EGR SI engine applications. Testing was performed in a constant-volume combustion chamber and in a single-cylinder research engine, both with varying levels of EGR. The EGR tolerance of the systems was determined, and it was found that ignition systems which can deliver their energy over a wide spatial area and a long temporal duration provided the best combustion performance. This finding helps to define the ignition system requirements for high-EGR SI engine applications.
Technical Paper
2014-10-13
Vijay Prakash Chougule
Abstract: In present experimental work a computerized Multi cylinder 1.2L Diesel engine with data acquisition system was used to study the effects of oxygen enriched air intake on combustion parameters. A method to reduce emissions of smoke and other pollutants from diesel engines is to enhance the oxygen supply to their combustion chamber. This can be accomplished by enriching the intake air stream with oxygen. The test performed to evaluate the combustion characteristics and engine performances of C.I Engine. Engine testing is performed with the oxygen concentration of intake air ranging from 21% to 27% by volume. Increasing the oxygen content with the air leads to faster burn rates and the ability to burn more fuel at the same stoichiometry. Added oxygen in the combustion air leads to shorter ignition delays and offers more potential for burning diesel. Experimental studies concerning the oxygen-enrichment of intake air, have revealed large decrease of ignition delay, drastic decrease of soot emissions as well as reduction of CO and HC emissions while, brake specific fuel consumption (BSFC) remained unaffected and increasing of power output is feasible.
Technical Paper
2014-10-13
Siva Subramanian Ravishankar, Aayush Mehrotra, Ghodke Pundlik Rambhaji, Simhachalam Juttu
One of the major challenges for automotive industry today is to reduce tailpipe emission without compromising on fuel economy especially with the EURO 6, RDE, LEV III emissions & CO2 norms coming up from year 2016 & beyond. In case of diesel engines, with the emission norms becoming more & more stringent worldwide it's becoming more & more difficult to improve tradeoff between NOx & PM emissions at engine level itself. After treatment systems give some edge in terms of tail pipe emission reduction but not on the cost, FE & system simplicity front. For diesel engines the compression ratio and design of the bowl geometry plays a crucial role in controlling emission & CO2. While reducing the reduced compression ratio gives benefit NOx & PM emissions, HC & CO emissions and the cold start ability are a major issue. The objective was to make a study of different bowl geometries that would help achieve this target of improving NOx vs PM tradeoff with minimum or no impact of HC, CO, fuel economy and noise.
Viewing 1 to 30 of 101935