scholarly journals An Experimental and Simulation Study of Early Flame Development in a Homogeneous-charge Spark-Ignition Engine

2017 ◽  
Vol 72 (5) ◽  
pp. 32
Author(s):  
Y. Shekhawat ◽  
D.C. Haworth ◽  
A. d'Adamo ◽  
F. Berni ◽  
S. Fontanesi ◽  
...  
Keyword(s):  
High Speed ◽  
Spatial Scales ◽  
Model Development ◽  
Optical Diagnostics ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Eddy Simulation ◽  
Computational Mesh ◽  
Flame Development ◽  
The Times

An integrated experimental and Large-Eddy Simulation (LES) study is presented for homogeneous premixed combustion in a spark-ignition engine. The engine is a single-cylinder two-valve optical research engine with transparent liner and piston: the Transparent Combustion Chamber (TCC) engine. This is a relatively simple, open engine configuration that can be used for LES model development and validation by other research groups. Pressure-based combustion analysis, optical diagnostics and LES have been combined to generate new physical insight into the early stages of combustion. The emphasis has been on developing strategies for making quantitative comparisons between high-speed/high-resolution optical diagnostics and LES using common metrics for both the experiments and the simulations, and focusing on the important early flame development period. Results from two different LES turbulent combustion models are presented, using the same numerical methods and computational mesh. Both models yield Cycle-to-Cycle Variations (CCV) in combustion that are higher than what is observed in the experiments. The results reveal strengths and limitations of the experimental diagnostics and the LES models, and suggest directions for future diagnostic and simulation efforts. In particular, it has been observed that flame development between the times corresponding to the laminar-to-turbulent transition and 1% mass-burned fraction are especially important in establishing the subsequent combustion event for each cycle. This suggests a range of temporal and spatial scales over which future experimental and simulation efforts should focus.

A semi-empirical laminar-to-turbulent flame transition model coupled with G equation for early flame kernel development and combustion in spark-ignition engines

2019 ◽  
pp. 146808741986474 ◽  
Author(s):  
Seunghwan Keum ◽  
Guangfei Zhu ◽  
Ronald Grover ◽  
Wei Zeng ◽  
Christopher Rutland ◽  
...  
Keyword(s):  
Turbulent Flame ◽  
Transition Process ◽  
Spark Ignition ◽  
Transition Function ◽  
Spark Ignition Engine ◽  
Navier Stokes ◽  
Flame Kernel ◽  
Eddy Simulation ◽  
Flame Development ◽  
Semi Empirical

It has been reported that early combustion in a spark-ignition engine determines the subsequent combustion. Also, the early combustion has a very strong correlation with cycle-to-cycle variability, which limits engine operating range. As such, accurate modeling of the early flame development is very important in accurate simulation of spark-ignition engine combustion. During the early flame development, the flame kernel, initiated by spark, grows initially at laminar flame speed. As the kernel grows, the flame surface wrinkles due to surface instability and interacts with the flow turbulence as the flame transitions from laminar to turbulent flame. In this study, a semi-empirical model is proposed to simulate the laminar-to-turbulent flame transition process during early spark-ignition combustion. A hyperbolic tangent function was used to emulate the laminar-to-turbulent flame speed transition process. The proposed transition function was evaluated during early flame kernel development for both Reynolds-averaged Navier–Stokes and large eddy simulation models against combustion analysis data from high-speed optical particle image velocimetry. Difference in Reynolds-averaged Navier–Stokes and large eddy simulation transition function was analyzed and discussed.

Optical diagnostics of early flame development in a DISI (direct injection spark ignition) engine fueled with n-butanol and gasoline

Energy ◽  
2016 ◽  
Vol 108 ◽  
pp. 50-62 ◽  
Author(s):  
Simona Silvia Merola ◽  
Cinzia Tornatore ◽  
Adrian Irimescu ◽  
Luca Marchitto ◽  
Gerardo Valentino
Keyword(s):  
Direct Injection ◽  
Optical Diagnostics ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Flame Development ◽  
Direct Injection Spark Ignition

scholarly journals Characterization of radiative heat transfer in a spark-ignition engine through high-speed experiments and simulations

2019 ◽  
Vol 74 ◽  
pp. 61
Author(s):  
Lucca Henrion ◽  
Michael C. Gross ◽  
Sebastian Ferreryo Fernandez ◽  
Chandan Paul ◽  
Samuel Kazmouz ◽  
...  
Keyword(s):  
Combustion Chamber ◽  
High Speed ◽  
Combustion Process ◽  
Spark Ignition ◽  
Infrared Emission ◽  
Spark Ignition Engine ◽  
Local Conditions ◽  
Molecular Gases ◽  
Eddy Simulation ◽  
Molecular Radiation

A combined experimental and Large-Eddy Simulation (LES) study of molecular radiation is presented for combustion in a homogeneous pre-mixed spark-ignition engine. Molecular radiation can account for ~10% of the engine heat loss and could have a noticeable impact on the local conditions within the combustion chamber. The Transparent Combustion Chamber (TCC) engine, a single-cylinder two-valve research engine with a transparent liner and piston for optical access, was used for this study. High-speed infrared emission spectroscopy and radiative post-processing of LES calculations have been performed to gain insight into the timescales and magnitude of radiative emissions of molecular gases during the combustion process. Both the measurements and simulations show significant Cycle-to-Cycle Variations (CCV) of radiative emission. There is agreement in the instantaneous radiative spectrum of experiment and simulation, but the crank-angle development of the radiative spectrum shows disagreement. The strengths and limitations of the optical experiments and radiative simulations are seen in the results and suggest pathways for future efforts in characterizing the influence of molecular radiation. In particular, focusing on the relative changes of the spectral features will be important as they contain information about the thermochemical properties of the gas mixture.

A comparison of butanol and ethanol flame development in an optical spark ignition engine

Fuel ◽  
2016 ◽  
Vol 170 ◽  
pp. 27-38 ◽  
Author(s):  
Ben G. Moxey ◽  
Alasdair Cairns ◽  
Hua Zhao
Keyword(s):  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Flame Development ◽  
Ethanol Flame

Combustion characteristics of a two-stroke spark ignition UAV engine fuelled with gasoline and kerosene (RP-3)

2018 ◽  
Vol 91 (1) ◽  
pp. 163-170 ◽  
Author(s):  
Rui Liu ◽  
Xiaoping Su ◽  
Xiaodong Miao ◽  
Guang Yang ◽  
Xuefei Dong ◽  
...  
Keyword(s):  
Spark Ignition ◽  
Combustion Characteristics ◽  
Spark Ignition Engine ◽  
Bench Test ◽  
Potential Hazard ◽  
Content Type ◽  
Combustion Performance ◽  
Development Period ◽  
Flame Development ◽  
Load Conditions

Purpose The purpose of this paper is to compare the combustion characteristics, including the combustion pressure, heat release rate (HRR), coefficient of variation (COV) of indicated mean effective pressure (IMEP), flame development period and combustion duration, of aviation kerosene fuel, namely, rocket propellant 3 (RP-3), and gasoline on a two-stoke spark ignition engine. Design/methodology/approach This paper is an experimental investigation using a bench test to reflect the combustion performance of two-stroke spark ignition unmanned aerial vehicle (UAV) engine on gasoline and RP-3 fuel. Findings Under low load conditions, the combustion performance and HRR of burning RP-3 fuel were shown to be worse than those of gasoline. Under high load conditions, the average IMEP and the COV of IMEP of burning RP-3 fuel were close to those of gasoline. The difference in the flame development period between gasoline and RP-3 fuel was similar. Practical implications Gasoline fuel has a low flash point, high-saturated vapour pressure and relatively high volatility and is a potential hazard near a naked flame at room temperature, which can create significant security risks for its storage, transport and use. Adopting a low volatility single RP-3 fuel of covering all vehicles and equipment to minimize the number of different devices with the use of a various fuels and improve the application safeties. Originality/value Most two-stroke spark ignition UAV engines continue to combust gasoline. A kerosene-based fuel operation can be applied to achieve a single-fuel policy.

Experimental and Theoretical Analysis of Flame Development and Misfire Phenomena in a Spark-Ignition Engine

1992 ◽  
Author(s):  
Josef Hacohen ◽  
Michael R. Belmont ◽  
Richard W.F. Thurley ◽  
Jim C. Thomas ◽  
E. Layton Morris ◽  
...  
Keyword(s):  
Theoretical Analysis ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Flame Development

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.

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