scholarly journals 1D numerical study on hydrogen injection enabling ultra-lean combustion in a small gasoline Spark Ignition engine

2020 ◽  
Vol 197 ◽  
pp. 06001
Author(s):  
Luigi Teodosio ◽  
Dino Pirrello ◽  
Luca Marchitto
Keyword(s):  
High Efficiency ◽  
Laminar Flame ◽  
Numerical Study ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Pollutant Emissions ◽  
Numerical Code ◽  
Hydrogen Addition ◽  
1D Model ◽  
The Impact

This paper deals with the effects of hydrogen port injection on combustion evolution, efficiency and exhaust emissions of a small turbocharged gasoline Spark-Ignition engine through a 1D numerical code. First, the experiments on the base engine architecture are performed at different speeds and at low/medium loads. The experimental findings are used to validate a 1D model of the whole engine, developed within a commercial code. 1D model is also refined with “user-defined” sub-models for an accurate description of the in-cylinder phenomena, namely turbulence, combustion, heat transfer, and emissions. In a second step, 1D model is virtually modified through the installation of an hydrogen injector in each intake runner, while the combustion sub-model also accounts for the impact of hydrogen addition on the laminar flame speed through a dedicated correlation. 1D simulations are performed at low/medium loads and fixed speed of 2250 rpm with 5% of hydrogen by volume in the intake air. Numerical investigations show that hydrogen addition to gasoline/air mixtures allows relevant efficiency benefits (up to a maximum percent gain of 19%), while the NO emissions are almost eliminated. Consequently, hydrogen-boosted combustion represents a potential solution to achieve very high efficiency and reduced pollutant emissions of gasoline spark ignition engines equipped with a conventional combustion system.

scholarly journals Effect of Cylinder-by-Cylinder Variation on Performance and Gaseous Emissions of a PFI Spark Ignition Engine: Experimental and 1D Numerical Study

2021 ◽  
Vol 11 (13) ◽  
pp. 6035
Author(s):  
Luigi Teodosio ◽  
Luca Marchitto ◽  
Cinzia Tornatore ◽  
Fabio Bozza ◽  
Gerardo Valentino
Keyword(s):  
Internal Combustion Engines ◽  
Numerical Study ◽  
Spark Ignition ◽  
Operating Conditions ◽  
Spark Ignition Engine ◽  
Combustion Stability ◽  
Pollutant Emissions ◽  
Gaseous Emissions ◽  
Performance And Emissions ◽  
The Impact

Combustion stability, engine efficiency and emissions in a multi-cylinder spark-ignition internal combustion engines can be improved through the advanced control and optimization of individual cylinder operation. In this work, experimental and numerical analyses were carried out on a twin-cylinder turbocharged port fuel injection (PFI) spark-ignition engine to evaluate the influence of cylinder-by-cylinder variation on performance and pollutant emissions. In a first stage, experimental tests are performed on the engine at different speed/load points and exhaust gas recirculation (EGR) rates, covering operating conditions typical of Worldwide harmonized Light-duty vehicles Test Cycle (WLTC). Measurements highlighted relevant differences in combustion evolution between cylinders, mainly due to non-uniform effective in-cylinder air/fuel ratio. Experimental data are utilized to validate a one-dimensional (1D) engine model, enhanced with user-defined sub-models of turbulence, combustion, heat transfer and noxious emissions. The model shows a satisfactory accuracy in reproducing the combustion evolution in each cylinder and the temperature of exhaust gases at turbine inlet. The pollutant species (HC, CO and NOx) predicted by the model show a good agreement with the ones measured at engine exhaust. Furthermore, the impact of cylinder-by-cylinder variation on gaseous emissions is also satisfactorily reproduced. The novel contribution of present work mainly consists in the extended numerical/experimental analysis on the effects of cylinder-by-cylinder variation on performance and emissions of spark-ignition engines. The proposed numerical methodology represents a valuable tool to support the engine design and calibration, with the aim to improve both performance and emissions.

scholarly journals LES study on mixing and combustion in a Direct Injection Spark Ignition engine

2018 ◽  
Vol 73 ◽  
pp. 32
Author(s):  
Nicolas Iafrate ◽  
Anthony Robert ◽  
Jean-Baptiste Michel ◽  
Olivier Colin ◽  
Benedicte Cuenot ◽  
...  
Keyword(s):  
Ignition Time ◽  
Direct Injection ◽  
Combustion Process ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Pollutant Emissions ◽  
Spark Ignition Engines ◽  
Eddy Simulation ◽  
Mixture Preparation ◽  
The Impact

Downsized spark ignition engines coupled with a direct injection strategy are more and more attractive for car manufacturers in order to reduce pollutant emissions and increase efficiency. However, the combustion process may be affected by local heterogeneities caused by the interaction between the spray and turbulence. The aim for car manufacturers of such engine strategy is to create, for mid-to-high speeds and mid-up-high loads, a mixture which is as homogeneous as possible. However, although injection occurs during the intake phase, which favors homogeneous mixing, local heterogeneities of the equivalence ratio are still observed at the ignition time. The analysis of the mixture preparation is difficult to perform experimentally because of limited optical accesses. In this context, numerical simulation, and in particular Large Eddy Simulation (LES) are complementary tools for the understanding and analysis of unsteady phenomena. The paper presents the LES study of the impact of direct injection on the mixture preparation and combustion in a spark ignition engine. Numerical simulations are validated by comparing LES results with experimental data previously obtained at IFPEN. Two main analyses are performed. The first one focuses on the fuel mixing and the second one concerns the effect of the liquid phase on the combustion process. To highlight these phenomena, simulations with and without liquid injection are performed and compared.

scholarly journals Potential of hydrogen addition to natural gas or ammonia as a solution towards low- or zero-carbon fuel for the supply of a small turbocharged SI engine

2021 ◽  
Vol 312 ◽  
pp. 07022
Author(s):  
Alfredo Lanotte ◽  
Vincenzo De Bellis ◽  
Enrica Malfi
Keyword(s):  
Alternative Fuels ◽  
Laminar Flame ◽  
Combustion Engine ◽  
Numerical Study ◽  
Combustion Process ◽  
Pollutant Emissions ◽  
Si Engine ◽  
Hydrogen Addition ◽  
Emission Regulations ◽  
Zero Carbon

Nowadays there is an increasing interest in carbon-free fuels such as ammonia and hydrogen. Those fuels, on one hand, allow to drastically reduce CO2 emissions, helping to comply with the increasingly stringent emission regulations, and, on the other hand, could lead to possible advantages in performances if blended with conventional fuels. In this regard, this work focuses on the 1D numerical study of an internal combustion engine supplied with different fuels: pure gasoline, and blends of methane-hydrogen and ammonia-hydrogen. The analyses are carried out with reference to a downsized turbocharged two-cylinder engine working in an operating point representative of engine operations along WLTC, namely 1800 rpm and 9.4 bar of BMEP. To evaluate the potential of methane-hydrogen and ammonia-hydrogen blends, a parametric study is performed. The varied parameters are air/fuel proportions (from 1 up to 2) and the hydrogen fraction over the total fuel. Hydrogen volume percentages up to 60% are considered both in the case of methane-hydrogen and ammonia-hydrogen blends. Model predictive capabilities are enhanced through a refined treatment of the laminar flame speed and chemistry of the end gas to improve the description of the combustion process and knock phenomenon, respectively. After the model validation under pure gasoline supply, numerical analyses allowed to estimate the benefits and drawbacks of considered alternative fuels in terms of efficiency, carbon monoxide, and pollutant emissions.

scholarly journals A comprehensive numerical study of the ethanol blended fuel effect on the performance and pollutant emissions in spark-ignition engine

2014 ◽  
Vol 18 (1) ◽  
pp. 29-38 ◽  
Author(s):  
Motlagh Zangooee ◽  
Razavi Modarres
Keyword(s):  
Numerical Study ◽  
Load Condition ◽  
Engine Performance ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Pollutant Emissions ◽  
Injection System ◽  
Thermodynamic State ◽  
Point Injection ◽  
Blended Fuel

In the present work, the performance and pollutant emissions in a spark ignition engine has been numerically investigated. For this purpose, the coupled KIVA code with CHEMKIN is used to predict the thermodynamic state of the cylinder charge during each cycle. Computations were carried out for a four cylinder, four strokes, multi point injection system (XU7 engine). Numerical cases have been performed up to 30% vol. of ethanol. Engine simulations are carried out at 2000, 2500 and 3000 rpm and full load condition. The numerical results showed that pollutant emissions reduce with increase in ethanol content. Based on engine performance, the most suitable fraction of ethanol in the blend was found to be nearly 15% for the XU7 engine.

scholarly journals Numerical Investigation of Fuel Property Effects on Mixed-Mode Combustion in a Spark-Ignition Engine

2020 ◽  
Vol 143 (4) ◽  
Author(s):  
Chao Xu ◽  
Pinaki Pal ◽  
Xiao Ren ◽  
Magnus Sjöberg ◽  
Noah Van Dam ◽  
...  
Keyword(s):  
Flame Propagation ◽  
Mixed Mode ◽  
Laminar Flame ◽  
Hybrid Approach ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Chemical Effect ◽  
Cfd Model ◽  
Auto Ignition ◽  
The Impact

Abstract In this study, lean mixed-mode combustion is numerically investigated using computational fluid dynamics (CFD) in a spark-ignition engine. A new E30 fuel surrogate is developed using a neural network model with matched octane numbers. A skeletal mechanism is also developed by automated mechanism reduction and by incorporating a NOx submechanism. A hybrid approach that couples the G-equation model and the well-stirred reactor model is employed for turbulent combustion modeling. The developed CFD model is shown to well predict pressure and apparent heat release rate (AHRR) traces compared with experiment. Two types of combustion cycles (deflagration-only and mixed-mode cycles) are observed. The mixed-mode cycles feature early flame propagation and subsequent end-gas auto-ignition, leading to two distinctive AHRR peaks. The validated CFD model is then employed to investigate the effects of NOx chemistry. The NOx chemistry is found to promote auto-ignition through the residual gas, while the deflagration phase remains largely unaffected. Sensitivity analysis is finally performed to understand effects of fuel properties, including heat of vaporization (HoV) and laminar flame speed (SL). An increased HoV tends to suppress auto-ignition through charge cooling, while the impact of HoV on flame propagation is insignificant. In contrast, an increased SL is found to significantly promote both flame propagation and end-gas auto-ignition. The promoting effect of SL on auto-ignition is not a direct chemical effect; it is rather caused by an advancement of the combustion phasing, which increases compression heating of the end-gas.

scholarly journals Ammonia Emissions in SI Engines Fueled with LPG

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 691
Author(s):  
Andrzej Żółtowski ◽  
Wojciech Gis
Keyword(s):  
Internal Combustion Engines ◽  
Fuel Mixture ◽  
Spark Ignition ◽  
Operating Conditions ◽  
Spark Ignition Engine ◽  
Pollutant Emissions ◽  
Catalytic Reactor ◽  
Si Engines ◽  
Engine Testing ◽  
The Impact

Ammonia is a toxic exhaust component emitted from internal combustion engines. Both pure ammonia and the products of its reaction with nitrogen and sulfur compounds, being the source of particulate matter (PM) emissions, are dangerous for human health and life. The aim of the article was to demonstrate that NH3 can be produced in exhaust gas after-treatment systems of spark-ignition (SI) engines used in light-duty vehicles. In some cases, NH3 occurs in high enough concentrations that can be harmful and dangerous. It would be reasonable to collect research data regarding this problem and consider the advisability of limiting these pollutant emissions in future regulations. The article presents the results of the spark-ignition engine testing on an engine test bench and discusses the impact of the air–fuel ratio regulation and some engine operating parameters on the concentration of NH3. It has been proven that in certain engine operating conditions and a combination of circumstances like the three-way catalytic reactor (TWC) temperature and periodic enrichment of the air–fuel mixture may lead to excessive NH3 emissions resulting from the NO conversion in the catalytic reactor. This is a clear disadvantage due to the lack of limitation of these pollutant emissions by the relevant type-approval regulations. This article should be a contribution to discussion among emissions researchers whether future emission regulations (e.g., Euro 7 or Euro VII) should include a provision to reduce NH3 emissions from all vehicles.

scholarly journals Ethanol/Gasoline Blends as Alternative Fuel in Last Generation Spark-Ignition Engines: A Review on CO and HC Engine Out Emissions

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 4034
Author(s):  
Paolo Iodice ◽  
Massimo Cardone
Keyword(s):  
Physicochemical Properties ◽  
Alternative Fuels ◽  
Experimental Studies ◽  
Alternative Fuel ◽  
Exhaust Emissions ◽  
Spark Ignition ◽  
Operating Conditions ◽  
Spark Ignition Engine ◽  
Spark Ignition Engines ◽  
The Impact

Among the alternative fuels existing for spark-ignition engines, ethanol is considered worldwide as an important renewable fuel when mixed with pure gasoline because of its favorable physicochemical properties. An in-depth and updated investigation on the issue of CO and HC engine out emissions related to use of ethanol/gasoline fuels in spark-ignition engines is therefore necessary. Starting from our experimental studies on engine out emissions of a last generation spark-ignition engine fueled with ethanol/gasoline fuels, the aim of this new investigation is to offer a complete literature review on the present state of ethanol combustion in last generation spark-ignition engines under real working conditions to clarify the possible change in CO and HC emissions. In the first section of this paper, a comparison between physicochemical properties of ethanol and gasoline is examined to assess the practicability of using ethanol as an alternative fuel for spark-ignition engines and to investigate the effect on engine out emissions and combustion efficiency. In the next section, this article focuses on the impact of ethanol/gasoline fuels on CO and HC formation. Many studies related to combustion characteristics and exhaust emissions in spark-ignition engines fueled with ethanol/gasoline fuels are thus discussed in detail. Most of these experimental investigations conclude that the addition of ethanol with gasoline fuel mixtures can really decrease the CO and HC exhaust emissions of last generation spark-ignition engines in several operating conditions.

scholarly journals Numerical study on the effects of intake charge on oxy-fuel combustion in a dual-injection spark ignition engine at economical oxygen-fuel ratios

2021 ◽  
pp. 146808742110222
Author(s):  
Xiang Li ◽  
Yiqiang Pei ◽  
Zhijun Peng ◽  
Tahmina Ajmal ◽  
Khaqan-Jim Rana ◽  
...  
Keyword(s):  
Combustion Engine ◽  
Numerical Study ◽  
Carbon Capture And Storage ◽  
Spark Ignition ◽  
Fuel Combustion ◽  
Spark Ignition Engine ◽  
Gasoline Direct Injection ◽  
Brake Mean Effective Pressure ◽  
Dual Injection ◽  
Injection Strategies

In order to decrease Carbon Dioxide (CO2) emissions, Oxy-Fuel Combustion (OFC) technology with Carbon Capture and Storage (CCS) is being developed in Internal Combustion Engine (ICE). In this article, a numerical study about the effects of intake charge on OFC was conducted in a dual-injection. Spark Ignition (SI) engine, with Gasoline Direct Injection (GDI), Port Fuel Injection (PFI) and P-G (50% PFI and 50% GDI) three injection strategies. The results show that under OFC with fixed Oxygen Mass Fraction (OMF) and intake temperature, the maximum Brake Mean Effective Pressure (BMEP) is each 5.671, 5.649 and 5.646 bar for GDI, P-G and PFI strategy, which leads to a considerable decrease compared to Conventional Air Combustion (CAC). [Formula: see text], [Formula: see text] and [Formula: see text] of PFI are the lowest among three injection strategies. With intake temperature increases from 298 to 378 K, the reduction of BMEP can be up to 12.68%, 12.92% and 12.75% for GDI, P-G and PFI, respectively. Meantime, there is an increase of about 3% in Brake Specific Fuel Consumption (BSFC) and Brake Specific Oxygen Consumption (BSOC). Increasing OMF can improve the performance of BMEP and BSFC, and the trend is more apparent under GDI strategy. Besides, an increasing tendency can be observed for cylinder pressure and in-cylinder temperature under all injection strategies with the increase of OMF.

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