Multidimensional Modeling of Premixed Turbulent Combustion: Modeling and Testing of a Small Spark-Ignition Engine

2001 ◽  
Author(s):  
Gustavo Fontana ◽  
Enzo Galloni ◽  
Elio Jannelli
Keyword(s):  
Turbulent Combustion ◽  
Combustion Process ◽  
Spark Ignition ◽  
Measured Data ◽  
Spark Ignition Engine ◽  
Combustion Model ◽  
Engine Operation ◽  
Premixed Turbulent Combustion ◽  
Combustion Models ◽  
Good Reproduction

Abstract Combustion models, used in spark-ignition engine modeling, are reviewed. Different approaches for representing the main combustion features are reported. Limitations in simulating such a complex phenomenon as turbulent combustion in engines are highlighted as well. In order to compare different combustion models, the multidimensional program KIVA-3V has been used. The behavior of an actual spark-ignition engine has been investigated. In particular, simulation results, using simple chemical kinetics and mixing-controlled models, are compared. The results obtained, compared to measured data, confirm that different combustion models can lead to a satisfactory prediction of engine performances. But, in many cases, these models require experimental data for determining the model characteristic constants. A hybrid combustion model is proposed. It is able to provide a good reproduction of engine combustion process and, in particular, the model seems to be less sensitive to the engine operation. The computation results are compared to the measured data.

Studying the effects of hydrogen addition on the second-law balance of a biogas-fuelled spark ignition engine by use of a quasi-dimensional multi-zone combustion model

2008 ◽  
Vol 222 (11) ◽  
pp. 2249-2268 ◽  
Author(s):  
C D Rakopoulos ◽  
C N Michos ◽  
E G Giakoumis
Keyword(s):  
Combustion Process ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Combustion Model ◽  
Second Law ◽  
Si Engine ◽  
Engine Operation ◽  
Hydrogen Addition ◽  
Cycle Simulation ◽  
Hydrogen Enrichment

Although a first-law analysis can show the improvement that hydrogen addition impacts on the performance of a biogas-fuelled spark-ignition (SI) engine, additional benefits can be revealed when the second law of thermodynamics is brought into perspective. It is theoretically expected that hydrogen enrichment in biogas can increase the second-law efficiency of engine operation by reducing the combustion-generated irreversibilities, because of the fundamental differences in the mechanism of entropy generation between hydrogen and traditional hydrocarbon combustion. In this study, an experimentally validated closed-cycle simulation code, incorporating a quasi-dimensional multi-zone combustion model that is based on the combination of turbulent entrainment theory and flame stretch concepts for the prediction of burning rates, is further extended to include second-law analysis for the purpose of quantifying the respective improvements. The analysis is applied for a single-cylinder homogeneous charge SI engine, fuelled with biogas—hydrogen blends, with up to 15 vol% hydrogen in the fuel mixture, when operated at 1500r/min, wide-open throttle, fuel-to-air equivalence ratio of 0.9, and ignition timing of 20° crank angle before top dead centre. Among the major findings derived from the second-law balance during the closed part of the engine cycle is the increase in the second-law efficiency from 40.85 per cent to 42.41 per cent with hydrogen addition, accompanied by a simultaneous decrease in the combustion irreversibilities from 18.25 per cent to 17.18 per cent of the total availability of the charge at inlet valve closing. It is also illustrated how both the increase in the combustion temperatures and the decrease in the combustion duration with increasing hydrogen content result in a reduction in the combustion irreversibilities. The degree of thermodynamic perfection of the combustion process from the second-law point of view is quantified by using two (differently defined) combustion exergetic efficiencies, whose maximum values during the combustion process increase with hydrogen enrichment from 49.70 per cent to 53.45 per cent and from 86.01 per cent to 87.33 per cent, respectively.

scholarly journals Numerical Study of Engine Performance and Emissions for Port Injection of Ammonia into a Gasoline\Ethanol Dual-Fuel Spark Ignition Engine

2021 ◽  
Vol 11 (4) ◽  
pp. 1441
Author(s):  
Farhad Salek ◽  
Meisam Babaie ◽  
Amin Shakeri ◽  
Seyed Vahid Hosseini ◽  
Timothy Bodisco ◽  
...  
Keyword(s):  
Numerical Study ◽  
Combustion Process ◽  
Engine Performance ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Combustion Model ◽  
Dual Fuel ◽  
Spark Ignition Engines ◽  
Performance And Emissions ◽  
Hc Emissions

This study aims to investigate the effect of the port injection of ammonia on performance, knock and NOx emission across a range of engine speeds in a gasoline/ethanol dual-fuel engine. An experimentally validated numerical model of a naturally aspirated spark-ignition (SI) engine was developed in AVL BOOST for the purpose of this investigation. The vibe two zone combustion model, which is widely used for the mathematical modeling of spark-ignition engines is employed for the numerical analysis of the combustion process. A significant reduction of ~50% in NOx emissions was observed across the engine speed range. However, the port injection of ammonia imposed some negative impacts on engine equivalent BSFC, CO and HC emissions, increasing these parameters by 3%, 30% and 21%, respectively, at the 10% ammonia injection ratio. Additionally, the minimum octane number of primary fuel required to prevent knock was reduced by up to 3.6% by adding ammonia between 5 and 10%. All in all, the injection of ammonia inside a bio-fueled engine could make it robust and produce less NOx, while having some undesirable effects on BSFC, CO and HC emissions.

A Multiple-Zone Cycle Simulation for Spark-Ignition Engines: Thermodynamic Details

2001 ◽  
Author(s):  
Jerald A. Caton
Keyword(s):  
Combustion Process ◽  
Load Condition ◽  
Engine Performance ◽  
Thermodynamic Cycle ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Engine Operation ◽  
Part Load ◽  
Cycle Simulation ◽  
The Individual

Abstract A thermodynamic cycle simulation was developed for a spark-ignition engine which included the use of multiple zones for the combustion process. This simulation was used to complete analyses for a commercial, spark-ignition V-8 engine operating at a part load condition. Specifically, the engine possessed a compression ratio of 8.1:1, and had a bore and stroke of 101.6 and 88.4 mm, respectively. A part load operating condition at 1400 rpm with an equivalence ratio of 1.0 was examined. Results were obtained for overall engine performance, for detailed in-cylinder events, and for the thermodynamics of the individual processes. In particular, the characteristics of the engine operation with respect to the combustion process were examined. Implications of the multiple zones formulation for the combustion process are described.

Modelling the early stage of spark ignition engine combustion using the KIVA-3V code incorporating an ignition model

2003 ◽  
Vol 4 (3) ◽  
pp. 179-192 ◽  
Author(s):  
L Andreassi ◽  
S Cordiner ◽  
V Rocco
Keyword(s):  
Early Stage ◽  
Combustion Process ◽  
Spark Ignition ◽  
Operating Conditions ◽  
Spark Ignition Engine ◽  
Gasoline Direct Injection ◽  
Combustion Model ◽  
Cylinder Wall ◽  
Predictive Capability ◽  
Wide Range

The evolution of early stages of homogeneous mixture combustion in spark ignition (SI) engines represents a critical period that greatly affects the whole combustion process. A proper description of this critical phase represents a major issue, which could strongly influence the overall model predictive capability (i.e. model ability to reproduce the real engine behaviour for a large range of operating conditions without any major tuning). Such requirements become even more important for the simulation of last-generation gasoline direct injection or lean stratified engines, where ignition could determine the functionality of the engine itself. In this paper, after a detailed analysis of the ignition physical process and its modelling issues, the predictive capability of the KIVA-3V code has been improved by substituting the original ignition procedure with a more detailed kernel evolution model based on the one presented by Herweg and Maly in 1992. The ignition model introduced in a KIVA-3V version already modified by the authors (re-zoning algorithm, combustion and turbulence models, cylinder wall heat transfer, etc.) has then been tested in order to assess its level of accuracy in describing this complex phenomenon, by varying the most critical engine operating conditions and keeping combustion tuning parameters unchanged. After comparing ignition model results with the corresponding ones presented by Herweg and Maly, a specific application of the overall model (KIVA-3V + ignition model + turbulent combustion model) has been made to perform an analysis of a compressed natural gas (CNG) fuelled engine for heavy-duty applications. To this aim, the in-cylinder combustion history and the related processes as the temperature distribution and NOx formation have been calculated and verified with reference to the experimental data measured in a wide range of operating conditions of an IVECO turbocharged engine.

Numerical and Experimental Characterization of a Natural Gas Engine With Partially Stratified Charge Spark Ignition

2010 ◽  
Vol 133 (2) ◽  
Author(s):  
E. C. Chan ◽  
M. H. Davy ◽  
G. de Simone ◽  
V. Mulone
Keyword(s):  
Natural Gas ◽  
Combustion Process ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Combustion Model ◽  
Turbulence Energy ◽  
Turbulent Fluctuation ◽  
Stratified Charge ◽  
Gas Engine ◽  
Natural Gas Engine

This paper outlines the development of a comprehensive numerical framework for the partially stratified charge (PSC) lean-burn natural gas engine. A 3D model of the engine was implemented to represent fluid motion and combustion. The spark ignition model was based on the works of Herweg and Maly (1992, “A Fundamental Model for Flame Kernel Formation in SI Engines,” SAE Technical Publication, Paper No. 922243) and Tan and Reitz (2006, “An Ignition and Combustion Model Based on the Level-Set Method for Spark Ignition Engine Multidimensional Modeling,” Combust. Flame, 145, pp. 1–15). The EDC model (Ertesvåg and Magnussen, 2000, “The Eddy Dissipation Turbulence Energy Cascade Model,” Combust. Sci. Technol., 159, pp. 213–235) with a two-step mechanism was used to model natural gas turbulent combustion process. An open geometry simulation strategy was adopted to account for intake-exhaust gas and valve movements. Each simulation was executed for multiple cycles to produce a representative residual gas fraction. The numerical results were compared with the experimental data obtained on the Ricardo Hydra single cylinder research engine for both homogeneous and PSC cases and they were found to be in excellent agreement in pressure trace and heat release rate. The detailed investigation of the numerical data showed the development of an ignitable mixture under PSC cases, allowing stable kernel growth well beyond the lean misfire limit of the bulk mixture. Furthermore, limits on successful ignition can be identified using the ignition model, which exhibited self-similar behavior in terms of flame speed and turbulent fluctuation. It can also be shown that, at ultralean air-fuel ratios, the PSC plume helps replicate the ignition conditions that can be found under stoichiometric operation.

An Experimental and Numerical Investigation of Spark Ignition Engine Operation on H2, CO, CH4, and Their Mixtures

2009 ◽  
Vol 132 (3) ◽  
Author(s):  
Hailin Li ◽  
Ghazi A. Karim ◽  
A. Sohrabi
Keyword(s):  
Combustion Process ◽  
Engine Performance ◽  
Spark Ignition ◽  
Combustion Characteristics ◽  
Spark Ignition Engine ◽  
Engine Operation ◽  
Dry Air ◽  
Fuel Mixtures ◽  
Co Addition ◽  
H2 Addition

The knock and combustion characteristics of CO, H2, CH4, and their mixtures were determined experimentally in a variable compression ratio spark ignition (SI) cooperative fuel research (CFR) engine. The significant effects of gaseous fuel mixtures containing H2 in enhancing the combustion and oxidation process of CH4 were examined. The unique combustion characteristics of CO in dry air and its distinct performance in mixtures with H-containing fuels were investigated. The addition of a simulated synthesis gas (2H2+CO) to CH4 was found to enhance the combustion process of the resulting mixture and lowers its knock resistance. The effectiveness of such an addition is slightly weaker than that of a comparable H2 addition but much stronger than that with CO addition only. A predictive model with detailed kinetic chemistry was used successfully to simulate SI engine operation fuelled with CH4, H2, CO, and their mixtures. The predicted engine performance and knock limits of CH4, H2, CO, and their mixtures agree well with experimental data with the exception around pure CO operation in dry air with the presence of small amounts of CH4 or H2. A remedial approach to improve the prediction of the knock limits of fuel mixtures containing mainly CO with a small amount of H-containing fuels such as H2 and CH4 was proposed and discussed.

scholarly journals The study of the spark ignition engine operation at fuelling with n-butanol-gasoline blends

2020 ◽  
Vol 180 ◽  
pp. 01010
Author(s):  
Cristian Sandu ◽  
Constantin Pană ◽  
Niculae Negurescu ◽  
Alexandru Cernat ◽  
Cristian Nuţu ◽  
...  
Keyword(s):  
Oxygen Content ◽  
Alternative Fuels ◽  
Internal Combustion Engines ◽  
Combustion Process ◽  
Good Alternative ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Engine Operation ◽  
High Oxygen Content ◽  
Combustion Properties

For conventional internal combustion engines alternative fuels such alcohols (ethanol, methanol and butanol) have attracted more attention. This aspect is due to the fact that alcohols have good combustion properties and high oxygen content. Butanol is a viable fuel for blending with conventional fuels such as gasoline or diesel because of its high miscibility with these conventional fuels. The high combustion speed of butanol compared to that of gasoline ensures a shorter burning process thus the engine thermal efficiency can potentially be improved. Moreover, the additional oxygen content of the alcohol n-butanol can potentially improve the combustion process and can lead to a reduction of carbon monoxide and unburnt hydrocarbons emissions level. Utilizing butanol-gasoline blends can provide a good solution for the reduction of greenhouse gases level (CO2) and pollutants level (CO, HC, and NOx). An experimental study was carried out in a spark ignition engine which was fueled with a blend of n-butanol-gasoline at different volume percentages. The objective of this paper is to determine the effects of butanol on the engine energetic performances and on the emissions (HC, CO and NOx). At first the engine fueled with pure gasoline to set up a reference at the engine load χ=55%, engine speed of n=2500 min-1 and different excess air coefficients (λ). After setting the reference the engine was fueled with butanol-gasoline blend (10% vol. butanol 90% vol. gasoline) with the same engine adjustments. At butanol use the CO, HC and CO2 emissions level decreased, but the NOx emission level increased. The butanol can be considered a good alternative fuel for the spark ignition engines without modifications.

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