Showing papers on "Spark-ignition engine published in 2009"
TL;DR: A comprehensive overview of hydrogen-fueled internal combustion engines (H 2 ICEs) can be found in this paper, where the authors discuss the fundamentals of the combustion of hydrogen, details on the different mixture formation strategies and their emissions characteristics, measures to convert existing vehicles, dedicated hydrogen engine features, a state of the art on increasing power output and efficiency while controlling emissions and modeling.
743 citations
TL;DR: In this article, the effects of unleaded gasoline (E0) and ethanol-ethanol blends (E50 and E85) on engine performance and pollutant emissions were investigated experimentally in a single cylinder four-stroke spark-ignition engine at two compression ratios (10:1 and 11:1).
318 citations
TL;DR: In this paper, large-Eddy simulation (LES) has been used to analyze the occurrence and the causes of cycle-to-cycle combustion variations in a spark ignited four-valve single cylinder engine fueled with a homogeneous propane-air mixture.
256 citations
TL;DR: An experimental study on the effect of hydrogen fraction and EGR rate on the combustion characteristics of a spark-ignition engine fueled with natural gas-hydrogen blends was investigated in this article.
247 citations
TL;DR: In this article, an experimental investigation on the influence of different hydrogen fractions and EGR rates on the performance and emissions of a spark-ignition engine was conducted, and the results showed that large EGR introduction decreases the engine power output.
229 citations
TL;DR: In this paper, the potential of a simple variable valve timing (VVT) system has been investigated and a numerical approach, based on both 1-D and 3-D computational models, has been adopted in order to evaluate the engine performance when load is controlled by the VVT system and to deeply investigate the influence, on in-cylinder phenomena, of the valve timing variation.
168 citations
TL;DR: In this article, an experimental study on the performance and exhaust emissions of a spark-ignition engine fuelled with methane-hydrogen mixtures was performed at different engine speeds and different excessive air ratios.
147 citations
TL;DR: In this article, the authors carried out a comparative study with regard to energy consumption and greenhouse gas emissions, in respect of two types of engines with three different fuels: diesel, biodiesel 30% (B30) and compressed natural gas (CNG).
128 citations
TL;DR: In this article, a single-cylinder hydrogen engine equipped with a supercharger and an exhaust gas recirculation (EGR) system was shown to significantly increase the power output while limiting tailpipe emissions of oxides of nitrogen (NOx).
118 citations
TL;DR: In this paper, a hydrogen spark-ignition engine was visualized with a high-speed color camera with a speed of 250 kframes/s, showing that the thermal boundary layer of an end-gas region was compressed by the propagating flame front, and that combustion of the lubricant oil grease was visible inside burned gas region.
107 citations
TL;DR: In this article, an experimentally validated closed cycle simulation code is used, based on a multi-zone thermodynamic model of the cylinder content, applied in conjunction with a quasi-dimensional combustion model for burn rate predictions.
TL;DR: In this paper, the combustion stability of a small spark-ignition engine has been investigated by means of both experimental tests and numerical analyses, and the cyclic variation in combustion has been measured at part load considering several combustion chamber geometries.
TL;DR: In this article, an experimental investigation of heat transfer inside a CFR spark ignition engine operated at a constant engine speed of 600 rpm is described. The heat flux is directly measured under motored and fired conditions with a commercially available thermopile sensor.
TL;DR: In this paper, the authors investigated the generating efficiency and pollutant emissions of a four-stroke spark-ignition gas engine generator operating on biogas-hydrogen blends of varying excess air ratios and hydrogen concentrations.
TL;DR: In this article, an experimental investigation has been performed on the potential of the Atkinson cycle and reducing intake oxygen concentration for pollutant control in a heavy-duty diesel engine, which has been carried out at low engine load (25%).
TL;DR: In this article, a spark ignition engine operated with DME blended LPG fuel was experimentally investigated, and the results showed that stable engine operation was possible for a wide range of engine loads up to 20% by mass DME fuel.
20 Apr 2009
01 Jul 2009
TL;DR: In this article, an experimental investigation was performed on the combustion performance, reduction characteristics of exhaust emissions, and engine performance of a spark ignition engine fuelled with bio-diesel fuel.
Abstract: An experimental investigation was performed on the combustion performance, reduction characteristics of exhaust emissions, and engine performance of a spark ignition engine fuelled with bio...
01 Jan 2009
TL;DR: In this paper, an experimental study on the combustion and emissions of a natural-gas direct-injection spark ignition engine under different compression ratios was carried out, and the results showed that the compression ratio has a large influence on the engine performance, combustion, and emissions.
Abstract: An experimental study on the combustion and emissions of a natural-gas direct- injection spark ignition engine under different compression ratios was carried out. The results show that the compression ratio has a large influence on the engine performance, combustion, and emissions. The penetration distance of the natural-gas jet is decreased and relatively strong mixture stratification is formed as the compression ratio is increased, giving a fast burning rate and a high thermal efficiency, especially at low and medium engine loads. However, the brake thermal efficiency is increased with a compression ratio up to a limit of 12 at high engine loads. The maximum cylinder gas pressure is increased with increase in the compression ratio. The flame development duration is decreased with increase in the compression ratio and this behaviour becomes more obvious with increase in the compression ratio at low loads or for lean mixture combustion. This indicates that the compression ratio has a significant influence on the combustion duration at lean combustion. The exhaust hydrocarbon (HC) and carbon monoxide emissions decreased with increase in the compression ratio, while the exhaust nitrogen oxide emission is increased with increase in the compression ratio. The exhaust HC emission tends to increase at high compression ratios. Experiments showed that a compression ratio of 12 is a reasonable value for a compressed-natural-gas direct-injection engine to obtain a better thermal efficiency without a large penalty of emissions.
TL;DR: In this paper, the authors provided an insight into the pre-ignition phenomenon and its relevant triggering mechanisms and presented results from a research project by Volkswagen AG Group Research, in cooperation with the Institute for Internal Combustion Engines and Automotive Engineering at Vienna University of Technology.
Abstract: The combination of gasoline direct injection and supercharging technologies allows the substitution of naturally aspirated engines through downsized supercharged engines with comparable performance. However, increasing the mean effective pressure is limited by the occurrence of unwanted pre-ignition phenomena. The following article provides an insight into the pre-ignition phenomenon and its relevant triggering mechanisms. The presented results stem from a research project by Volkswagen AG Group Research, in cooperation with the Institute for Internal Combustion Engines and Automotive Engineering at Vienna University of Technology.
TL;DR: In this paper, the formation of soot was studied in an n-heptane fuelled homogeneous charge compression Ignition (HCCI) engine, operated at a rich equivalence ratio of 1.93.
Abstract: At the University of Cambridge, the formation of soot was studied in an n-heptane fuelled Homogeneous Charge Compression Ignition (HCCI) engine, operated at a rich equivalence ratio of 1.93, by means of in-cylinder snatch sampling as well as by applying a new engine model which features a highly detailed description of soot. This new computationally efficient model is capable of providing not only averaged quantities as functions of crank angle like soot mass, number density, volume fraction, aggregate diameter, and the number of primary particles per aggregate for example, but also aggregate and primary particle size distribution functions and additionally can give detailed information on aggregate morphology and chemical composition.
TL;DR: In this paper, the effect of spark advance, fuel ratio, and cylinder internal wall temperature on the power output and efficiency of the engine at any rotational speed, ω, was analyzed.
Abstract: By performing quasidimensional computer simulations and finite-time thermodynamic analysis we study the effect of spark advance, fuel ratio, and cylinder internal wall temperature in spark ignition engines. We analyze the effect of these parameters on the power output and efficiency of the engine at any rotational speed, ω. Moreover, we propose the optimal dependence on ω of the spark advance angle and the fuel ratio with the objective to get maximum efficiency for any fixed power requirement. The importance of engine power-efficiency curves in order to perform this optimization procedure and also of the evaluation of macroscopic work losses in order to understand the physical basis of the optimization process is stressed. Taking as reference results from simulations with constant standard values of spark advance, fuel ratio, and cylinder internal wall temperature, the optimized parameters yield to substantial increases in engine performance parameters.
TL;DR: This paper examines the cycle-to-cycle variations of peak pressure pmax and peak pressure angle αpmax in a four-cylinder spark ignition engine for three different spark advance angles to show that depending on the spark advance angle, there are significant differences in the fluctuations ofpmax and αPMax.
Abstract: In this paper we analyze the cycle-to-cycle variations of peak pressure pmax and peak pressure angle αpmax in a four-cylinder spark ignition engine. We examine the experimental time series of pmax and αpmax for three different spark advance angles. Us- ing standard statistical techniques such as return maps and histograms we show that depending on the spark advance angle, there are significant differences in the fluctuations of pmax and αpmax. We also calculate the multiscale entropy of the various time series to esti- mate the effect of randomness in these fluctuations. Finally, we explain how the information on both pmax and αpmax can be used to develop optimal strategies for controlling the combustion process and improving engine performance.
TL;DR: In this article, the use of LPG liquid phase fuel in a 1.5 liter SI four cylinder gasoline engine with double over head camshafts, four valves per cylinder, and centrally located DI injector is explored.
Abstract: Direct Injection (DI) is believed to be one of the key strategies for maximizing the thermal efficiency of Spark Ignition (SI) engines and meet the ever-tightening emissions regulations. This paper explores the use of Liquefied Petroleum Gas (LPG) liquid phase fuel in a 1.5 liter SI four cylinder gasoline engine with double over head camshafts, four valves per cylinder, and centrally located DI injector. The DI injector is a high pressure, fast actuating injector enabling precise multiple injections of the finely atomized fuel sprays. With DI technology, the injection timing can be set to avoid fuel bypassing the engine during valve overlap into the exhaust system prior to combustion. The fuel vaporization associated with DI reduces combustion chamber and charge temperatures, thereby reducing the tendency for knocking. Fuel atomization quality supports an efficient combustion process. Furthermore, the spray-guided combustion process has significant thermodynamic benefits over wall or air guided combustion resulting is near optimal combustion. Injection timings and compression ratio are optimized for best performances over Wide Open Throttle (WOT) conditions running homogeneous at stoichiometry or spray-guided stratified lean of stoichiometry. The paper also explores advantages of Jet Ignition (JI) versus standard SI in the lean spray-guided stratified mode of operation. Effects of fuel properties on gas exchange, mixture formation, in-cylinder charge cooling, wall-spray interactions, turbulent combustion evolution and knock occurrence are taken into account. Results are presented in terms of brake mean effective pressure, specific fuel consumption, efficiency and specific CO 2 production showing significant improvements of LPG over gasoline for the reduced green house gas formation potential. This paper is a contribution to the development of a high efficiency gaseous fuel SI engine for the Australian market.
Patent•
02 Nov 2009
TL;DR: A fuel management system for using water for on-board vehicular separation of ethanol from ethanol-gasoline blends is described in this paper, where water or a water-alcohol mixture from a secondary tank is mixed with the ethanol-gaseoline blend resulting in separation of the ethanol.
Abstract: A fuel management system for using water for on-board vehicular separation of ethanol from ethanol-gasoline blends is described. Water or a water-alcohol mixture from a secondary tank is mixed with the ethanol-gasoline blend resulting in separation of the ethanol. By using on-board vehicular separation, the consumption of the externally supplied liquid from a secondary tank can be decreased to less than 1% of the gasoline consumption. This allows for long refilling periods for the externally supplied fluid. In another embodiment, a water-based fluid is directly injected into the cylinders of a spark ignition engine to eliminate knocking without causing misfire. In a further embodiment, an alcohol-based fluid is also used in those circumstances where injection of the water-based fluid may cause misfire.
TL;DR: In this paper, a variable-valve-timing (VVT) actuator is used to produce internal exhaust gas recirculation, providing beneficial effects in terms of fuel consumption and pollutant emissions reduction.
01 Jan 2009
TL;DR: In this article, the authors examined results from a thermodynamic engine cycle simulation of a spark ignition engine with exhaust gas recirculation (EGR) for an automotive engine using isooctane.
Abstract: This work examines results from a thermodynamic engine cycle simulation of a spark ignition engine with exhaust gas recirculation (EGR). EGR is a common feature of today's engines and is an effective technique to reduce combustion temperatures and nitrogen oxide emissions. Results were obtained for an automotive engine using isooctane. These results are presented as functions of EGR for constant load and speed, and as functions of load and speed for constant EGR level. For both a cooled and an adiabatic EGR configuration, the thermal efficiency first increased, reached a maximum, and then decreased as the EGR levels increased. The thermodynamic gains were largely due to favourable thermodynamic properties, reduced cylinder wall heat losses, and, for part-throttle operation, reduced pumping losses as the EGR level increased. The destruction of availability during the combustion process was highest for the cooled EGR configuration. For the cases examined, the destruction of availability due to combu...
TL;DR: In this article, the cycle-by-cycle variations of a natural gas direct-injection spark ignition engine at different compression ratios were investigated and the results showed that the lean burn limit of the natural-gas direct injection engine can be extended to a larger overall excess air ratio compared with that of the homogeneous charge natural gas engine.
Abstract: Cycle-by-cycle variations of a natural gas direct-injection spark ignition engine at different compression ratios were investigated. The results show that the lean burn limit of the natural-gas direct injection engine can be extended to a larger overall excess air ratio compared with that of the homogeneous charge natural gas engine. The coefficient of variations (CoV) of indicated mean effective pressure decreases with the increase of compression ratio. However, CoV of indicated mean effective pressure is increased at high engine load when compression ratio is larger than 12. The cycle-by-cycle variations are more clearly demonstrated in CoV of indicated mean effective pressure rather than in CoV of cylinder peak pressure. Average values of flame development duration, main combustion duration, and total combustion duration are decreased and combustion is improved with increasing compression ratio. This is the reason for decreasing cycle-by-cycle variations in the natural gas direct-injection engine. Bett...
20 Aug 2009
TL;DR: In this article, the emissions of an ammonia and gasoline dual-fueled spark ignition engine were measured and the clean-up region occurs between stoichiometric and 0.2% rich.
Abstract: Engine-out and post-catalyst emissions of ammonia, hydrocarbons, nitric oxide, carbon monoxide, and nitrous oxide are measured for an ammonia and gasoline dual fueled spark ignition engine. An ordinary three-way catalytic converter can be used to clean up these emissions. The clean-up region occurs between stoichiometric and 0.2% rich. Ordinary exhaust gas oxygen sensors are usable with ammonia and gasoline in much the same way as they are with gasoline alone.Copyright © 2009 by ASME
TL;DR: In this paper, an approach to SA mapping is presented, with the objective of improving the performance analysis robustness, while reducing the test time, based on the observation that, for a given running condition, IMEP can be considered a function of the combustion phasing, represented by the 50% Mass Fraction Burned (MFB50) parameter.
Abstract: Engines performance and efficiency are largely influenced by the combustion phasing. Operating conditions and control settings influence the combustion development over the crankshaft angle: the most effective control parameter used by Electronic Control Units (ECU) to optimize the combustion process for Spark Ignition (SI) engines is Spark Advance (SA). SA mapping is a time-consuming process, usually carried out with the engine running in steady state on the test bench, changing SA values while monitoring Brake and Indicated Mean Effective Pressure (BMEP, IMEP) and Brake Specific Fuel Consumption (BSFC). Mean values of IMEP and BSFC for a test carried out with a given SA setting are considered as the parameters to optimize. However, the effect of SA on IMEP and BSFC is not deterministic, due to the cycle-to-cycle variation: the analysis of mean values requires many engine cycles to be significant of the performance obtained with the given control setting. Finally other elements, such as engine or components ageing, and disturbances like Air-to-Fuel Ratio (AFR) or air, water and oil temperature variations, could affect the tests results: this facet can be very significant for racing engines testing. This paper presents a novel approach to SA mapping, with the objective of improving the performance analysis robustness, while reducing the test time. The methodology is based on the observation that, for a given running condition, IMEP can be considered a function of the combustion phasing, represented by the 50% Mass Fraction Burned (MFB50) parameter. Due to cycle-to-cycle variation, many different MFB50 and IMEP values are obtained during a steady state test carried out with constant SA. While MFB50 and IMEP absolute values are influenced by disturbance factors, the relationship between them holds, and it can be synthesized by means of the angular coefficient of the tangent line to the MFB50-IMEP distribution. The angular coefficient variations as a function of SA can be used to feed a SA controller, able to maintain the optimal combustion phasing. Similarly, knock detection is approached by evaluating two indexes: the distribution of a typical knock-sensitive parameter (MAPO, Maximum Amplitude of Pressure Oscillations) is related to that of CHRNET (net Cumulative Heat Release), determining a robust knock index. A knock limiter controller can then be added, in order to restrict the SA range to safe values. The methodology can be implemented in real-time combustion controllers: the algorithms have been applied offline to sampled data, showing the feasibility of fast and robust automatic mapping procedures.Copyright © 2009 by ASME