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Viewing 91 to 120 of 44126
2017-10-08
Technical Paper
2017-01-2248
Haichun Ding, Wenbin Zhang, Xiao Ma, Shi-Jin Shuai, Bin Zheng, Alex Cantlay, Vinod Natarajan, Zhang Song Zhan, Bin Liu
Abstract Gasoline direct injection (GDI) engine technology is now widely used due to its high fuel efficiency and low CO2 emissions. However, particulate emissions pose one challenge to GDI technology, particularly in the presence of fuel injector deposits. In this paper, a 4-cylinder turbocharged GDI engine in the Chinese market was selected and operated at 2000rpm and 3bar BMEP condition for 55 hours to accumulate injector deposits. The engine spark timing, cylinder pressure, combustion duration, brake specific fuel consumption (BSFC), gaseous pollutants which include total hydro carbon (THC), NOx (NO and NO2) and carbon dioxide (CO), and particulate emissions were measured before and after the injector fouling test at eight different operating conditions. Test results indicated that mild injector fouling can result in an effect on engine combustion and emissions despite a small change in injector flow rate and pulse width.
2017-10-08
Technical Paper
2017-01-2251
Lei Feng, Beiling Chen, Haifeng Liu, Mingfa Yao, Chao Geng
Abstract The flame structure and combustion characteristics of wall-impinging diesel fuel spray were investigated in a high-temperature high-pressure constant volume combustion vessel. The ambient temperature (Ta) was set to 773 K. The wall temperatures (Tw) were set to 523 K, 673 K and 773 K respectively. Three different injection pressures (Pi) of 600 bar, 1000bar and 1600bar, two ambient pressures (Pa) of 2 MPa and 4 MPa were applied. The flame development process of wall-impinging spray was measured by high-speed photography, which was utilized to quantify the flame luminosity intensity, ignition delay and flame geometrical parameters. The results reveal that, as the wall temperature increases, the flame luminosity intensity increases and the ignition delay decreases.
2017-10-08
Technical Paper
2017-01-2255
Raul Payri, Jaime Gimeno, Santiago Cardona, Sridhar Ayyapureddi
Abstract A prototype multi-hole diesel injector operating with n-heptane fuel from a high-pressure common rail system is used in a high-pressure and high-temperature test rig capable of reaching 1100 Kelvin and 150 bar under different oxygen concentrations. A novel optical set-up capable of visualizing the soot cloud evolution in the fuel jet from 30 to 85 millimeters from the nozzle exit with the high-speed color diffused back illumination technique is used as a result of the insertion of a high-pressure window in the injector holder opposite to the frontal window of the vessel. The experiments performed in this work used one wavelength provide information about physical of the soot properties, experimental results variating the operational conditions show the reduction of soot formation with an increase in injection pressure, a reduction in ambient temperature, a reduction in oxygen concentration or a reduction in ambient density.
2017-10-08
Technical Paper
2017-01-2254
Sirui Huang, Changpu Zhao, Yayong Zhu
Abstract In order to improve the combustion and emissions for high-speed marine diesel engines, numerical investigations on effects of different combustion chamber structures combined with intake air humidification have to be conducted. The study uses AVL Fire code to establish three-dimensional combustion model and simulate the in-cylinder flow, air-fuel mixing and combustion process with the flow dynamics metrics such as swirl number and uniformity index, analyze the interactional effects of combustion chamber structures and intake air humidification against the experimental data for a part load operation at 1350 r/min, find the optimized way to improve engine performance as well as decrease the NOx and soot emissions. The novelty is that this study is to combine different air humidifying rates with different combustion chamber structures including the re-entrant chamber, the straight chamber and the open chamber.
2017-10-08
Technical Paper
2017-01-2275
Chen Yang, Weixin li, Jiandong Yin, Yuan Shen
Abstract In order to meet increasingly stringent emission regulations and reduce fuel consumption, development of modern powertrain is becoming more complicated, combining many advanced technologies. Gasoline engine downsizing is already established as a proven technology to reduce vehicle fleet CO2 emissions. Compressed natural gas (CNG) offers increased potential to further reduce both tailpipe CO2 and other regulated exhaust gas emissions without compromising driving performance. In this study, a turbocharged CNG port fuel injection (PFI) engine was developed based on gasoline version. Making most use of positive fuel properties of CNG, the paper quantifies the performance characteristics of downsized CNG engine considering reduced knock sensitivity, adaption of compression ratio and combustion efficiency. While peak cylinder pressure was controlled below 120 bar, peak torque 180Nm, same level as gasoline variant, was realized from 3000rpm.
2017-10-08
Technical Paper
2017-01-2277
Xiao Peng, Han Wu, Chia-Fon Lee, Qianbo Sun, Fushui Liu
Abstract Methanol has been regarded as a potential transportation fuel due to its advanced combustion characteristics and flexible source. However, it is suffering from misfire and high HC emissions problems under cold start and low load conditions either on methanol SI engine or on methanol/diesel dual fuel engine. Hydrogen is a potential addition that can enhance the combustion of methanol due to its high flammability and combustion stability. In the current work, the effect of hydrogen fraction on the laminar flame characteristics of methanol- hydrogen-air mixture under varied equivalence ratio was investigated on a constant volume combustion chamber system coupled with a schlieren setup. Experiments were performed over a wide range of equivalence ratio of the premixed charge, varied from 0.8 to 1.4, as well as different hydrogen fraction, 0%, 5%, 10%, 15% and 20% (n/n). All tests were carried out at fixed temperature and pressure of 400K and 0.1MPa.
2017-10-08
Technical Paper
2017-01-2280
Yuzuru Nada, So Morimoto, Yoshiyuki Kidoguchi, Ryu Kaya, Hideaki Nakano, Shinichi Kobayashi
Abstract The aim of this study is to clarify the mixture formation in the combustion chamber of our developed natural gas engine incorporating the sub-chamber injection system, in which natural gas is directly injected into a combustion sub-chamber in order to completely separate rich mixture in the sub-chamber, suitable for ignition, from ultra-lean mixture in the main chamber. Mixture distributions in chambers with and without sub-chamber were numerically simulated at a variety of operating conditions. The commercial software of Fluent 16.0 was used to conduct simulations based on Reynolds averaged Navier-Stokes equations in an axial 2 dimensional numerical domain considering movements of piston. Non-reactive flow in the combustion chamber was simulated before the ignition timing at an engine speed of 2000 rpm. The turbulence model employed here is standard k-ε model. Air-fuel ratio is set with a lean condition of 30.
2017-10-08
Technical Paper
2017-01-2281
Lang Jiang, Zhe Kang, Zhehao Zhang, Zhijun Wu, Jun Deng, Zongjie Hu, Liguang Li
Abstract The present work aims at optimizing diesel engine combustion efficiency with optimized water injection strategy. The engine had been modified based on a two-cylinder mechanical pump diesel engine into common rail diesel engine with capability of direct water injection. The direct water injection system was designed and manufactured independently. An air-fluid booster was utilized to establish the water injection pressure up to 40MPa. Customized diesel injector was selected to be used as water injector in this study. Water injection strategy was optimized in detail with injection timing around TDC which ranges from 12°CA BTDC to -5°CA BTDC under 10 bar IMEP. The engine efficiency can be improved under selected water injection strategy due to the increment of work fluid in the combustion chamber. Moreover, the nitric oxides emissions show decrement around 10%.
2017-10-08
Technical Paper
2017-01-2282
Gen Chen, Wenxin Cai, Jianguang Zhou, Christian Spanner, Heribert Fuchs, Werner Schrei, Karl Weihrauch
Abstract A TGDI (turbocharged gasoline direct injection) engine is developed to realize both excellent fuel economy and high dynamic performance to guarantee fun-to-drive. In order to achieve this target, it is of great importance to develop a superior combustion system for the target engine. In this study, CFD simulation analysis, steady flow test and transparent engine test investigation are extensively conducted to ensure efficient and effective design. One dimensional thermodynamic simulation is firstly conducted to optimize controlling parameters for each representative engine operating condition, and the results serve as the input and boundary condition for the subsequent Three-dimensional CFD simulation. 3D CFD simulation is carried out to guide intake port design, which is then measured and verified on steady flow test bench.
2017-10-08
Technical Paper
2017-01-2284
Haifei Zheng
Abstract The potential benefits of reheat burner placed between turbine stages for propulsion system have been recognized for nearly a century. Compared to the conventional non-reheat engines, the turbine inter-guide-vane burner (TIB) engines by using jet-swirl flow scheme (high-G loading) are shown to have a higher specific thrust with no or only small increase in thrust specific fuel consumption. But, it is a known fact that the G loading in the circumferential cavity is inversely proportional to the radius of the circumferential cavity. If one needs to scale this configuration for a larger spool of turbine components, the effeciency of the high G operation and obtained benefits on flame speed will reduce and hence the performance will de-grade.
2017-10-08
Technical Paper
2017-01-2265
Hao-ye Liu, Zhi Wang, Bowen Li, Shi-Jin Shuai, Jian-Xin Wang
Abstract Wide Distillation Fuel (WDF) refers to the fuels with a distillation range from initial boiling point of gasoline to final boiling point of diesel. Recent experimental results have shown WDF by blending 50% gasoline and 50% diesel (G50) exhibits much lower soot emissions than diesel at medium load with similar thermal efficiency. However, the engine performances fueled by G50 at both low load end and high load end are still unknown. In this study, the combustion and emission characteristics of G50 and diesel are compared over a wide load range from 0.2 MPa IMEP to 1.4 MPa IMEP at a light-duty diesel engine. The results shown that at 0.2 MPa IMEP, G50 exhibits low combustion stability and thermal efficiency. With the increase of load, the poor combustion quality of G50 is improved. G50 can achieve soot-free combustion up to 1.0 MPa IMEP, while diesel cannot.
2017-10-08
Technical Paper
2017-01-2266
Bin Yang, Hu Wang, Mingfa Yao, Zunqing Zheng, Jialin Liu, Naifeng Ma, Qiping Wang, Haien Zha, Peng Chen
Abstract Gasoline partially premixed combustion shows the potential to achieve clean and high-efficiency combustion. Injection strategies show great influence on in-cylinder air flow and in-cylinder fuel distribution before auto-ignition, which can significantly affect the combustion characteristics and emissions. This study explored the effects of various injection strategies, including port fuel injection (PFI), single direct injection (DIm), double direct injection (DIp+DIm) and port fuel injection coupled with a direct injection (PFI+DIm) on the combustion characteristics and emissions in a modified single cylinder heavy-duty diesel engine fueled with 92# gasoline at low load. The investigation consists of two parts. Firstly, the comparison among PFI, PFI+DIm, and DIp+DIm strategies was conducted at a fixed CA50 to explore the effects of PFI+DIm and DIp+DIm strategies on the thermal efficiency and combustion stability.
2017-10-08
Technical Paper
2017-01-2267
Erik Svensson, Lianhao Yin, Per Tunestal, Martin Tuner
Abstract The concept of Partially Premixed Combustion (PPC) in internal combustion engines has shown to yield high gross indicated efficiencies, but at the expense of gas exchange efficiencies. Most of the experimental research on partially premixed combustion has been conducted on compression ignition engines designed to operate on diesel fuel and relatively high exhaust temperatures. The partially premixed combustion concept on the other hand relies on dilution with high exhaust gas recirculation (EGR) rates to slow down the combustion which results in low exhaust temperatures, but also high mass flows over cylinder, valves, ports and manifolds. A careful design of the gas exchange system, EGR arrangement and heat exchangers is therefore of utter importance. Experiments were performed on a heavy-duty, compression ignition engine using a fuel consisting of 80 volume % 95 RON service station gasoline and 20 volume % n-heptane.
2017-10-08
Technical Paper
2017-01-2268
Zhanming Chen, Long Wang, Tiancong Zhang, Qimeng Duan, Bo Yang
Abstract Engines fuelled with Liquefied natural gas (LNG) have been widely used in the heavy-duty vehicles. However, they suffer from poor combustion performance and flame instability under fuel-lean condition. In this work, experiments were performed on a turbo-charged, spark-ignition engine fuelled with natural gas (NG) and methanol. The combustion characteristics such as in-cylinder pressure, heat release rate (HRR), burned mass fraction (BMF), ringing/knock intensity (RI), ignition delay, centroid of HRR, and coefficient of variation (COV) of indicated mean effective pressure (IMEP) were analyzed under light load (brake mean effective pressure=0.3876 MPa) with different methanol substitution rates (MSR=0%, 16%, 34%, 46%). The experimental results showed that combustion phase advanced with the increase in MSR due to faster burning velocity of methanol. Knock only occurred at MSR=46%, 2000 rpm.
2017-10-08
Technical Paper
2017-01-2269
Shijun Dong, Xiaobei Cheng, Biao Ou, Can Yang, Zhaowen Wang, Fumin Pan
Abstract Based on a composed PRF/ethanol/PAH mechanism, simulations were conducted to investigate the combustion characteristics of n-heptane spray under premixed ethanol/air and iso-octane/air atmosphere in a combustion vessel. The effects of premixed ethanol and iso-octane on ignition delay, important soot precursors and soot volume fraction of n-heptane spray were studied. Also, simulated results with and without considering the cooling effects of premixed fuel vaporization were compared. When the cooling effect of premixed fuel vaporization was not considered, simulations showed that premixed ethanol could increase the ignition delay of n-heptane spray at ambient temperatures below 850K. However, premixed iso-octane showed little inhibition effect on ignition of n-heptane spray. Also, it was found that both premixed ethanol and iso-octane contributed to faster ignition under high ambient temperatures.
2017-10-08
Technical Paper
2017-01-2270
Fushui Liu, Yue Kang, Han Wu, Chia-Fon Lee, Yikai Li
Abstract CNG-diesel dual fuel combustion mode has been regarded as a practical operation strategy because it not only can remain high thermal efficiency but also make full use of an alternative fuel, natural gas. However, it is suffering from misfire and high HC emissions under cold start and low load conditions. As known, hydrogen has high flammability. Thus, a certain proportion of hydrogen can be added in the natural gas (named HCNG) to improve combustion performance. In this work, the effect of hydrogen volume ratio on combustion characteristics was investigated on an optically accessible single-cylinder CNG-diesel engine using a Phantom v7.3 color camera. HCNG was compressed into the tank under different hydrogen volume ratios varied from 0% to 30%, while the energy substitution rate of` HCNG remained at 70%.
2017-10-08
Technical Paper
2017-01-2271
Zhongshu Wang, Mingyang Shao, Ming Li, Dan Wang, Zhongchang Liu
Abstract For diesel/natural gas dual fuel engines, the combustion of pilot diesel injection plays an important role to subsequent mixture combustion process. To better understand the effects of multiple injections, a detailed study was conducted on a 6-cylinder turbocharged intercooler diesel/natural gas dual fuel heavy-duty engine at low loads. Multiple variables were tested, including the single injection timings, the multiple injections timings and the mass ratios. The investigated results showed that the multiple pilot diesel injections have an obvious effect on not only pilot diesel combustion process but also natural gas mixture combustion process. Early injection leads to a pilot-diesel-ignition-mode and it is a two-stage auto ignition mode. This mode differs from the compression ignition mode of traditional diesel engine in regard to its random occurrence location within the spray.
2017-10-08
Technical Paper
2017-01-2273
Xiaokun Nie, Wanhua Su
Abstract A numerical simulation was performed to investigate the pilot ignited natural gas combustion process in a direct injection natural gas engine. Various mixture distribution characteristics were compared in terms of the evolution of mixture equivalent ratio distributions and mixture concentration stratifications around top dead center (TDC). Based on above, the pilot injections were specially designed to investigate ignition core formation and its effects on natural gas combustion process. The result shows that pilot ignition sites have great impacts on pilot fuel ignition process and natural gas combustion process. The pilot ignition site on the region with rich NG/Air mixture is disadvantageous to the pilot fuel ignition due to a lack of oxygen, which is not beneficial to ignition core formation.
2017-10-08
Technical Paper
2017-01-2294
Julien Gueit, Jerome Obiols
Abstract In order to be ever more fuel efficient the use of Direct Injection (DI) is becoming standard in spark ignition engines. When associated with efficient turbochargers it has generated a significant increase in the overall performance of these engines. These hardware developments lead to increased stresses placed upon the fuel and the fuel injection system: for example injection pressures increased up to 400 bar, increased fuel and nozzle temperatures and contact with the flame in the combustion chamber. DISI injectors are thus subjected to undesirable deposit formation which can have detrimental consequences on engine operation such as reduced power, EOBD (Engine On Board Diagnostics) issues, impaired driveability and increased particulate emissions. In order to evaluate the sensitivity of DI spark ignition engines to fuel-related injector deposit formation, a new engine test procedure has been developed.
2017-10-08
Technical Paper
2017-01-2300
Wei Du, Juejue Lou, Fushui Liu
Abstract As known, the constant injection mass is a criterion for measuring the thermal efficiency of diesel engines. In this study, the effects of nozzle hole diameter on diesel free-spray characteristics were investigated in constant injection mass condition. The experiment was performed in a constant volume combustion chamber equipped with a high pressure common-rail injector that can change nozzles. Three single-hole axis nozzles with different hole diameters were used. High speed camera and Schlieren visualization set-up were used to capture the spray behaviors of liquid phase and vapor phase respectively. For liquid phase spray, the higher nozzle hole diameter, the higher were the liquid phase spray penetration rate and the saturated liquid phase spray penetration length. The saturated liquid phase spray penetration length wound not grow but oscillate around different mean values at the steady stage.
2017-10-08
Technical Paper
2017-01-2297
Thomas Dubois, Lidwine Abiad, Pauline Caine
Abstract As it is the case for Diesel engines, the Gasoline Direct Injection engines are using higher and higher injection pressures. The state of the art gasoline Direct Injection (GDI) engines are currently using injection pressures as high as 500 bar. A lot of work is also currently ongoing on Gasoline Compression Ignition (GCI) engines which use even higher injection pressures (above 1 000 bar). A high injection pressure means that a high pressure pump has to be used and so, proper lubricity has to be brought by the fuel. In the mean time the use of biofuels is increasing and several studies have shown the positive impact of ethanol on the energy consumption of gasoline engines mainly thru an octane number effect.
2017-10-08
Technical Paper
2017-01-2287
Aniseh Abdalla, Guoyang Wang, Jun Zhang, Shi-Jin Shuai
Abstract Advanced exhaust after-treatment technology is required for heavy-duty diesel vehicles to achieve stringent Euro VI emission standards. Diesel particulate filter (DPF) is the most efficient system that is used to trap the particulate matter (PM), and particulate number (PN) emissions form diesel engines. The after-treatment system used in this study is catalyzed DPF (CDPF) downstream of diesel oxidation catalyst (DOC) with secondary fuel injection. Additional fuel is injected upstream of DOC to enhance exothermal heat which is needed to raise the CDPF temperature during the active regeneration process. The objective of this research is to numerically investigate soot loading and active regeneration of a CDPF on a heavy-duty diesel engine. In order to improve the active regeneration performance of CDPF, several factors are investigated in the study such as the effect of catalytic in filter wall, soot distribution form along filter wall, and soot loads.
2017-10-08
Technical Paper
2017-01-2290
Zhixin Sun, Shaoqing Yang, Xinyong Qiao, Zhiyuan Zhang
Abstract When operating at high elevation of 3700m (atmospheric pressure about 68 kPa), the combustion process of diesel engine deteriorates, and the engine performance declines significantly. In this paper, Isooctyl Nitrate(EHN) is blended into the diesel fuel as additive to improve the combustion process. The decomposition of Isooctyl Nitrate(EHN) is analyzed and its mechanism is studied through chemical kinetics. A series of tests were carried out on a single cylinder diesel engine to study the effects of EHN on diesel engine combustion with the low intake pressure of 68kPa. Results show that the generation of OH、 H、 HO2 and H2O2 in n-heptane cleavage reactions can be promoted by EHN. In both stages of low and high temperature, the decomposition of n-heptane is accelerated, which shortened the ignition delay period. Four kinds of fuel are studied by tests: diesel fuel, diesel fuel with 0.3%, 0.6% and 0.9% mass fraction EHN respectively.
2017-10-08
Technical Paper
2017-01-2313
Zenghui Yin, Xiaojun Jing, Tieqiang Fu, Hua Zhou, Chunde Yao, Jiangtao Hu, Peilin Geng
Abstract In-cylinder direct-injected technology provides a flexible and accurate optimization for internal combustion engines to reduce emission and improve fuel efficiency. With increasingly stringent requirements for the emissions of nitrogen oxides (NOx) and CO2, the content of injections in an engine combustion cycle has reached 7 to 9 times in gasoline direct injection (GDI) and the diesel engine with high-pressure common rail (HPCR). Accurate control of both time and quantity of injection is critical for engine performance and emissions, while the dynamic response of injector spray characteristics is a key factor. In this paper, a test bench was built for monitoring the dynamic response of solenoid injectors with high-speed micro-photography and synchronous current collection system. Experimental studies on the dynamic response of GDI and HPCR solenoid injectors were carried out.
2017-10-08
Technical Paper
2017-01-2289
Chunze Cen, Han Wu, Chia-Fon Lee, Shuxin Hao, Fushui Liu, Yikai Li
Abstract Droplets impacting onto the heated surface is a typical phenomenon either in CI engines or in GDI SI engines, which is regarded significant for their air-fuel mixing. Meanwhile, alcohols including ethanol and butanol, has been widely studied as internal combustion engine alternative fuels due to their excellent properties. In this paper, under different component ratio conditions, the ethanol-butanol droplet impacting onto the heated aluminum surface has been studied experimentally. The falling height of the droplets were set at 5cm. A high-speed camera, set at 512×512pixels, 5000 fps and 20 μs of exposure time, was used to visualize the droplet behavior impinging onto the hot aluminum surface. The impact regimes of the binary droplet were identified. The result showed that the Leidenfrost temperature of droplets was affected by the ratio of ethanol to butanol. The higher the content of butanol in the droplet, the higher the Leidenfrost temperature.
2017-10-08
Technical Paper
2017-01-2314
Genmiao Guo, Zhixia He, Qian Wang, Shenxin Sun, Zhou Chen
Abstract Study of the spray formation in vicinity of the nozzle is essential to better understand and predict the physical processes involved in the diesel atomization. The initial spray patterns were found to be different from one injection to another during our visualization experiments, which was carried out based on a long distance microscope with a high speed camera in this work. It was found that the initial spray might contain a clear single mushroom, tail region and intact liquid column, or have a tail in front of the mushroom without changing its direction. Occasionally, it presented as a double-mushroom shape, or did not include a clear mushroom. Our visualization results showed that the various spray structures were observed at different injection pressures and different injection cycles under the same injection pressure.
2017-10-08
Technical Paper
2017-01-2310
Xiaoyan Jia, Baigang Sun, Dongwei Wu, Dan Xu, Wei Zang, Wei Shang, Jie Wang
Abstract The control valve is the most important implementation part of a high pressure common rail system, and its flow characteristics have a great influence on the performance of an injector. In this paper, based on the structure and the working principle of an electromagnetic injector in a high pressure common rail system, a simulation model of the injector is established by AMESim software. Some key parameters of the control valve, including the volume of the control chamber, the diameter of the orifice Z (feeding orifice), the diameter of the orifice A (discharge orifice) and the hole diameter of the fuel diffusion hole are studied by using this model. The results show that these key structural parameters of the control valve have a great influence on the establishment of the control chamber pressure and the action of the needle valve.
2017-10-08
Technical Paper
2017-01-2312
Raouf Mobasheri, Rahman Akbari
Abstract The scope of this work is to investigate the simultaneous effects of injection pressure and Exhaust Gas Recirculation (EGR) on mixture formation and engine performance in a High Speed Direct Injection (HSDI) diesel engine. For this, the computational results have been firstly compared to the measured data and a good agreement has been achieved in order to predict the in-cylinder pressure, heat release rate and the amount of NOx and soot emissions. Then, various injection pressures have been studied to explore its benefits to achieve the low exhaust emission at different EGR rates. The results show, while no EGR has been applied, decreasing the nozzle diameter causes the reduction of Indicate Specific Fuel Consumption (ISFC) with an increase in Indicated Mean Effective Pressure (IMEP).
2017-10-08
Technical Paper
2017-01-2319
Alessandro Montanaro, Luigi Allocca, Maurizio Lazzaro
Abstract GDI injection systems have become dominant in passenger cars due to their flexibility in managing and advantages in the fuel economy. With the increasingly stringent emissions regulations and concurrent requirements for enhanced engine thermal efficiency, a comprehensive characterization of the fuel spray behavior has become essential. Different engine loads produce in a variety of fuel supplying conditions that affect the air/fuel mixture preparation and influence the efficiency and pollutant production. The flash boiling is a particular state that occurs for peculiar thermodynamic conditions of the engine. It could strongly influence the mixture in sub-atmospheric environments with detrimental effects on emissions. In order to obtain an in-depth understanding of the flash boiling phenomena, it is necessary to study the parameters influencing the mixture formation and their appearance in diverse engine conditions.
2017-10-08
Technical Paper
2017-01-2317
Om Prakash Saw, Yashas Karaya, J M Mallikarjuna
Abstract The mixture formation in gasoline direct injection (GDI) engines operating at stratified condition plays an important role in deciding the combustion, performance and emission characteristics of the engine. In a wall-guided GDI engine, piston profile is such that the injected fuel is directed towards the spark plug to form a combustible mixture at the time of ignition. In these engines, fuel injection pressure and timing play an important role in creating a combustible mixture near the spark plug. Therefore, in this study, an attempt has been made to understand the effect of fuel injection pressure with single and split injection strategy on the mixture formation in a four-stroke, wall-guided GDI engine operating under stratified conditions by using computational fluid dynamics (CFD) analysis. Four fuel injection pressures viz., 90, 120, 150 and 180 bar are considered for the analysis.
Viewing 91 to 120 of 44126