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Training / Education
2015-03-02
Public awareness regarding pollutants and their adverse health effects has created an urgent need for engineers to better understand the combustion process as well as the pollutants formed as by-products of that process. To effectively contribute to emission control strategies and design and develop emission control systems and components, a good understanding of the physical and mathematical principles of the combustion process is necessary. This seminar will bring issues related to combustion and emissions "down to earth," relying less on mathematical terms and more on physical explanations and analogies.
Event
2014-10-21
Separate sub-sessions cover zero-dimensional, one-dimensional, and quasi-dimensional models for simulation of SI and CI engines with respect to: engine breathing, boosting, and acoustics; SI combustion and emissions; CI combustion and emissions; fundamentals of engine thermodynamics; numerical modeling of gas dynamics; thermal management; mechanical and lubrication systems; system level models for controls; system level models for vehicle fuel economy and emissions predictions.
Event
2014-10-21
This session focuses on technologies such as advanced and partially mixed combustion, cooled EGR boosting, ignition and direct injection technologies, pressure boosting, intelligent combustion, thermal efficiency, fully variable valvetrains, and other new and developing technologies. Papers focused on waste heat recovery technologies should be submitted to HX102/103.
Event
2014-10-21
This session covers the Power Cylinder: piston, piston rings, piston pins, and connecting rods. The papers include information on reducing friction and increasing fuel economy, improving durability by understanding wear, and decreasing oil consumption and blow-by.
Event
2014-10-21
This session covers topics regarding new CI and SI engines and components. This includes analytical, experimental, and computational studies covering hardware development as well as design and analysis techniques.
Event
2014-10-21
This session focuses on technologies such as advanced and partially mixed combustion, cooled EGR boosting, ignition and direct injection technologies, pressure boosting, intelligent combustion, thermal efficiency, fully variable valvetrains, and other new and developing technologies. Papers focused on waste heat recovery technologies should be submitted to HX102/103.
Event
2014-10-20
Mixed modes with both flame propagation and slow auto ignition. Distinct from SI knock: autoignition is desired and will not ruin the engine. Papers describing experiments and test data, simulation results focused on applications, fuel/additive effects, and SACI mode change are invited and will be placed in appropriate sub-sessions. Papers with an emphasis on the modeling aspects of combustion are encouraged to be submitted into PFL 110 or PFL120 modeling sessions.
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
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 Bunce, Hugh Blaxill
With an increasing global awareness of the need to conserve fuel resources and reduce carbon dioxide emissions, the automotive sector has been seeking gains in engine efficiency. One such method for achieving these gains on a spark ignition (SI) engine platform is through lean burn operation. Lean burn operation has demonstrated the ability to increase thermal efficiency, but this increase is often accompanied by increases in criteria pollutants, namely nitrogen oxides (NOx). By contrast, ultra-lean operation (λ>2) has demonstrated the ability to increase thermal efficiency and significantly reduce NOx due primarily to lower mean gas temperatures. Turbulent Jet Ignition (TJI), a pre-chamber-based combustion system, is a technology that enables ultra-lean operation through an effective de-coupling of the λ values in the pre-chamber and the main combustion chamber. TJI is also an effective knock mitigation system due to the distributed nature of main chamber ignition, resulting in rapid burn rates.
Technical Paper
2014-10-13
Wei Guo, Henry Guo, Xiaowei Du, Daniel Wang
ABSTRACT In recent years, the temperature of automobile exhaust gas is on a rising trend due to lowering pollutant emissions and improving fuel economy, and exhaust gas temperature reaches as high as 1000 deg in the case of gasoline engine cars. Turbocharger is widely used to boost engine due to low emissions, fuel economy and low cost reasons. As one of the hot components, it is subjected extreme hostile environment. Against this background, stainless steel has been chosen extensively as a turbine housing material for the gasoline engine cars. However, stainless steel has become a material of great cost volatility due to high Nickel content to resist oxidation which price is expensive. Meanwhile, austenitic ductile iron possesses favorable thermal fatigue properties, good material cost stability and good castability. It is considered to be promising substitutions for the stainless steel in most of gasoline engine cars in which the exhaust gas temperature reaches up to 950 deg. Low levels of engine noise, vibration and harshness and high acceptance of vehicle sound quality are critical for achieving passenger preference and satisfaction in the modern passenger car.
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
Jacek Andrzej Czarnigowski
The search for environmentally friendly fuels and ways of reducing carbon dioxide emissions is the main cause of a growing interest in gaseous fuels and corresponding fuel systems for internal combustion engines. To assure the expected environmental advantages with no detriment to the engine performance, these fuel systems need to be equipped with precise actuators – the gas injectors. The key input required in the process of designing and calibrating such fuel systems are precise characteristics of the injectors and understanding what affects these characteristics. The paper presents the results of experiments on the effects of supply pressure and supply voltage on the pulse gas injector opening time. Two characteristics have been investigated into: the opening lag time and the opening time. The opening lag was defined as the time between the occurence of a control signal and the moment of the valve’s starting to move. The lag determines the minimal duration of the control signal that can be executed by the injector, and thus the injector’s applicability.
Technical Paper
2014-10-13
Bo Hu, Chris Brace, Sam Akehurst, Colin Copeland, J.W.G. Turner
One of the major limits for two-stage-regulated turbocharged SI engines is its large backpressure and the corresponding degraded combustion efficiency. Divided exhaust period (DEP) concept is an approach which has been proved to significantly reduce the backpressure while still maintaining the same engine performance. The standard layout of the DEP system only comprises of a single turbocharger. Two exhaust valves are separately functioned with one valve feeding the blow-down pulse to the turbine whilst the other valve targeting the scavenging by bypassing the turbine. This method can provide large BSFC improvement due to improved breathing characteristics and better combustion phasing. The DEP concept has only been applied to single turbocharged engines so far. However, it in its basic form is in no way restricted to one-stage system. This paper, for the first time, applied DEP concept to a two-stage-regulated downsized SI engine. By controlling the timing of the exhaust valves separately to feed the exhaust to the high-pressure-turbine or low-pressure turbine or the exhaust pipe, it is anticipated that such system could achieve even better breathing characteristics than the standard one-stage turbocharged engine.
Technical Paper
2014-10-13
Mohd Farid Muhamad Said, Azhar Bin Abdul Aziz, Zulkanain Abdul Latiff, Amin Mahmoudzadeh Andwari, Shahril Nizam Mohamed Soid
Many efforts have been invested to improve the fuel efficiency of vehicles mainly for the local consumers. The production of a downsized turbocharged engine in the last quarter of 2011 proves that Malaysian is racing towards producing high efficiency engines along with other manufacturers. The effort does not only end there, several research activities on other alternative technology including cylinder deactivation (CDA) has begun. In this paper, the main research area is focus on the investigation of cylinder deactivation (CDA) technology on common engine part load conditions within Malaysian city driving operation. CDA mostly being applied on multi cylinders engines. It has the advantage in improving fuel consumption by reducing pumping losses at part load engine conditions. Here, the application of CDA on 1.6 liter four cylinders gasoline engine is studied. One-dimensional (1-D) engine modeling is performed to investigate the effect of intake and exhaust valve strategy on engine performance with CDA.
Technical Paper
2014-10-13
Florian Kleiner, Marcel Kaspar, 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
Lyes Tarabet, Mohand Said Lounici, Khaled Loubar, Mohand Tazerout
The use of computer engine cycle simulations, based on zero-dimensional (single zone or multi-zone) or multi-dimensional models, to aid engine systems design process has been largely applied and has become a popular tool because of combination of accurate results and reduced costs. In these models, the combustion sub-model plays a critical role in the overall engine simulation as it provides the heat release rate (HRR), which represents the combustion process for a given engine geometry and set of operating conditions. The determination of the experimental HRR is obtained solving the first law of Thermodynamics in the cylinder closed cycle with the aid of measured in-cylinder pressure. The widely used model in modern reciprocating Diesel engine applications to predict the HRR is the approximation by means of a correlation based on the combination of at least two Wiebe functions. This correlation has a characteristic S-shaped curve, which grows from zero indicating the start of combustion and tends exponentially to one indicating the end of combustion.
Technical Paper
2014-10-13
Yasuhiro Hikita, Masahiro Kawahara, Naoto Noguchi
Oil supplying device for each cam of a camshaft is called 'Cam-Shower'. Newdesign of cam-shower has been developed. The developed design can reduce oil flow of a cam-shower, so that discharge rate of oil pump can be reduced and its driving torque gets lower. Its effect on low fuel consumption is estimated at 0.1% in JC08 mode testing of Japan. At the beginning of developing new cam-shower, optimal oil flow to each camwas verified by visualizing with transparent cylinder head cover of valve train. Conventional cam-shower is simple straight pipe shape with several same size outlets to each cam. Oil from cylinder head is supplied in the middle of cam-shower pipe. The oil flow of outlet near supplied point is large amount, and outlet far from supplied point is small. But this conventional design of cam-shower satisfies lubricating performance for each cam because lubrication condition is adjusted to the far outlet. Therefore the excess amount of oil flow can afford to reduce. It is found thatsum of excess oil flow reaches 90% of total volume.
Technical Paper
2014-10-13
Pawel Magryta, Miroslaw Wendeker, Adam Majczak, Michal Bialy, Ksenia Siadkowska
Nowadays more sophisticated ways are search for alternative supply of combustion engines. One of the commonly used alternative fuels is hydrogen. On the market there are quite a number of passenger cars, which are powered by hydrogen fuel. The development of this technology is primarily connected with the introduction of hydrogen refueling stations, and hydrogen storage and distribution systems. We can predict that much faster popularization trend of hydrogen fuel would bring the possibility of modifying the existing fuel supply systems of internal combustion engines for use this environmentally friendly fuel. Adaptation of existing vehicles equipped with spark-ignition engines in the ability to support combustion by dosing additional dose of hydrogen would enable the introduction of this alternative fuel on a larger scale than at present. In order to verify the assumptions of the additive supplying hydrogen, simulation test model of a spark ignition engine, developed in the AVL BOOST software was presented in the article.
Technical Paper
2014-10-13
Timothy J. Jacobs, Louis Camilli, Matthias Neubauer
A key element to achieving vehicle emission certification for most light-duty vehicles using spark-ignition engine technology is prompt catalyst warming. Emission mitigation largely does not occur while the catalyst is below its “light-off temperature”, which may take several minutes to achieve when the engine starts from a cold condition. Such long periods of time are enough to fail a vehicle during its emission certification; it is necessary to minimize the catalyst warm up period to mitigate emissions as quickly as possible. One technique used to minimize catalyst warm up is to calibrate the engine in such a way that it delivers high temperature exhaust. At idle or low speed/low-low conditions, this can be done by advancing spark timing with a corresponding increase in fuel flow rate and / or leaning the mixture. Both approaches, however, encounter limits as combustion stability degrades, unburned hydrocarbon and carbon monoxide emissions rise excessively, and / or nitrogen oxide emissions rise excessively.
Technical Paper
2014-10-13
Yuanzhe Zhong, Sahil Sane
Electronic controls in internal combustion engines require an in-cylinder combustion sensor to produce a feedback signal to the ECU (Engine Control Unit). Recent research indicated that the ion current sensor has many advantages over the pressure transducer, related mainly to lower cost. Modified glow plugs in diesel engines, and fuel injectors in both gasoline and diesel engines can be utilized as ion current sensors without the addition any part or drilling holes in the cylinder head needed for the pressure transducer. Multi sensing fuel injector (MSFI) system is a new technique which instruments the fuel injector with an electric circuit to perform multiple sensing tasks including functioning as an ion sensor in addition to its primary task of delivering the fuel into the cylinder. It is necessary to fundamentally understand MSFI system. In this study the author will firstly explore the influence of piston motion (as one side of variable capacitance) on the ion sensor signal through modeling and simulation, and then look into the origin of the MSFI signal of fuel injection; and finally the author will look at how to analyze MSFI signal to duplicate the injection command profile for on-board diagnostics (OBD).
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
Lukasz Grabowski
In this study, the effect of the gas injector distance from an inlet valve on the combustion process under varied of injection timing in an LPG fuelled spark ignition engine was investigated. The test were performed at an engine test stand, where operating conditions for engine work such as crankshaft rotational speed, inlet manifold pressure and coolant temperature were maintained stable. The experiment was carried out on an indirect injection spark ignition engine under partial load and at the constant speed. To perform the experiments, holes in the inlet pipes were made, for four variants of injection nozzle distance from the combustion chamber into which 4 mm diameter nozzles were successively tested. Each distance was measured along the symmetry axis of the inlet port, which represents a real path of the fuel-air mixture. The OPTRAND fibre optic sensor with an ignition adapter was used to measure cylinder pressure. The results show that the engine performance is affected more by the injector distance from the inlet valve than by varied LPG injection timing.
Technical Paper
2014-10-13
Ben G. Moxey, Alasdair Cairns, Hua Zhao
The work was concerned with experimental study of the turbulent flame development process of ethanol fuels in an optically accessed spark ignition research engine. The fuels were evaluated in a single cylinder engine equipped with full-bore overhead optical access and operated at typical stoichiometric part-load conditions. High-speed natural light (or chemiluminescence) imaging and simultaneous in-cylinder pressure data measurement and analysis were used to understand the fundamental influence of both low and high ethanol content on turbulent flame propagation and subsequent mass burning. Causes for the difference in cyclic variations were evaluated in detail, with comparisons made to existing burning velocity correlations where available. Overall, it was concluded that the faster burning exhibited with pure ethanol fuel was the result of marginally higher initial laminar-like burning providing a “head start” to the turbulent flame development process, with the turbulent spectrum more quickly encroached leading to reduced bulk flame distortion and faster in-cylinder pressure development.
Technical Paper
2014-10-13
Antonio Mariani, Fabrice Foucher
Internal combustion engine downsizing allows the reduction of fuel consumption, in particular for those applications where the engine operates frequently at part load conditions. This design solution is usually combined with intake charge dilution by means of exhaust gas recirculation, for the purpose of limiting abnormal combustion events, reducing pumping losses and nitrogen oxide formation. While the exhaust gas recirculation is widely used in compression ignition engines, it still causes some technological issues, in particular for spark ignition engines. This paper presents the results of an experimental campaign performed on a spark ignition engine for the investigation of different dilution techniques for low temperature combustion. Nitrogen, carbon dioxide and exhaust gas recirculation have been adopted as diluents, comparing engine performance and pollutant emissions. The paper describes the obtained results with the aim at determining the optimal intake gas composition for low temperature combustion.
Technical Paper
2014-10-13
Bo Hu, Colin Copeland, Chris Brace, Sam Akehurst, Alessandro Romagnoli, Ricardo Martinez-Botas, J.W.G Turner
Turbocharged engines when operating at high engine speed and load cannot fully utilize the exhaust energy as the wastegate is opened to prevent overboost. Meanwhile, engines equipped with pressure charging systems are more prone to knock partly due the increased intake temperature. The expansion-cooling concept thus is conceived to reduce the intake temperature by recovering some otherwise unexploited exhaust energy. This concept can be applied to any twin charged (supercharger and turbocharger) engine system with an intercooler in between. The turbocharging system is designed to achieve maximum utilization of the exhaust energy, from which the intake charge is overboosted. After the intercooler, the supercharging system behaves like a turbine to expand the over-compressed intake charge and reduce its temperature whilst recovering some energy through the connection to the camshaft. It is anticipated that such a concept has benefits for knock resistance and energy recovery while suffering higher pumping losses.
Technical Paper
2014-10-13
Patrick Smith, Wai K. Cheng, John Heywood
The effects of piston top-land crevice size on the indicated fuel conversion efficiency are assessed in a single cylinder SI engine with 465 cc displacement. The operating conditions are at 3.6 and 5.6 bar net indicated mean effective pressure (NIMEP), and at 1500 and 2000 rpm speeds. The crevice volume is varied from 524 to 1157 mm^3 by changing the top land height from 3 to 7 mm, and by changing the top-land clearance from 0.247 to 0.586 mm. For a 1000 mm3 reduction in the top land crevice volume (measured cold), the indicated net fuel conversion efficiency increases by 1.8 percentage points at 3.6 bar NIMEP, and by 1.6 percentage points at 5.6 bar NIMEP. The results are not sensitive to the engine speeds under test. These values are consistent with a simple crevice filling and discharge/oxidation model.
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
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.
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