A Study of Turbulent Flame Development with Ethanol Fuels in an Optical Spark Ignition Engine

2014 ◽  
Author(s):  
Ben G. Moxey ◽  
Alasdair Cairns ◽  
Hua Zhao
Keyword(s):  
Turbulent Flame ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Flame Development

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.

An Experimental Investigation of Early Flame Development in an Optical Spark Ignition Engine Fueled With Natural Gas

2018 ◽  
Vol 140 (8) ◽  
Author(s):  
Cosmin E. Dumitrescu ◽  
Vishnu Padmanaban ◽  
Jinlong Liu
Keyword(s):  
Natural Gas ◽  
Flame Propagation ◽  
Combustion Engine ◽  
Turbulent Flame ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Piston Bowl ◽  
Pressure Trace ◽  
Flame Development ◽  
Flame Region

Improved internal combustion engine simulations of natural gas (NG) combustion under conventional and advanced combustion strategies have the potential to increase the use of NG in the transportation sector in the U.S. This study focused on the physics of turbulent flame propagation. The experiments were performed in a single-cylinder heavy-duty compression-ignition (CI) optical engine with a bowl-in piston that was converted to spark ignition (SI) NG operation. The size and growth rate of the early flame from the start of combustion (SOC) until the flame filled the camera field-of-view were correlated to combustion parameters determined from in-cylinder pressure data, under low-speed, lean-mixture, and medium-load conditions. Individual cycles showed evidence of turbulent flame wrinkling, but the cycle-averaged flame edge propagated almost circular in the two-dimensional (2D) images recorded from below. More, the flame-speed data suggested different flame propagation inside a bowl-in piston geometry compared to a typical SI engine chamber. For example, while the flame front propagated very fast inside the piston bowl, the corresponding mass fraction burn was small, which suggested a thick flame region. In addition, combustion images showed flame activity after the end of combustion (EOC) inferred from the pressure trace. All these findings support the need for further investigations of flame propagation under conditions representative of CI engine geometries, such as those in this study.

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

A comparative study of the effect of compression ratio on the efficiency and flame development angle in a Cooperative Fuel Research engine fueled with binary gasoline–alcohol blends

2019 ◽  
pp. 146808741985910 ◽  
Author(s):  
Guillermo Rubio-Gómez ◽  
Lis Corral-Gómez ◽  
David Rodriguez-Rosa ◽  
Fausto A Sánchez-Cruz ◽  
Simón Martínez-Martínez
Keyword(s):  
Comparative Study ◽  
Compression Ratio ◽  
Alternative Fuels ◽  
Internal Combustion Engines ◽  
Fossil Fuels ◽  
Combustion Process ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Flame Development ◽  
The Impact

In the last few years, increasing concern about the harmful effects of the use of fossil fuels in internal combustion engines has been observed. In addition, the limited availability of crude oil has driven the interest in alternative fuels, especially biofuels. In the context of spark ignition engines, bioalcohols are of great interest owing to their similarities and blend capacities with gasoline. Methanol and ethanol have been widely used, mainly due to their knocking resistance. Another alcohol of great interest is butanol, thanks to its potential of being produced as biofuel and its heat value closer to gasoline. In this study, a comparative study of gasoline–alcohol blend combustion, with up to 20% volume, with neat gasoline has been carried out. A single-cylinder, variable compression ratio, Cooperative Fuel Research-type spark ignition engine has been employed. The comparison is made in terms of fuel conversion efficiency and flame development angle. Relevant information related to the impact in the combustion process of the use of the three main alcohols used in blends with gasoline has been obtained.

The nature of early flame development in a lean-burn stratified-charge spark-ignition engine

2004 ◽  
Vol 136 (3) ◽  
pp. 283-302 ◽  
Author(s):  
P.G. Aleiferis ◽  
A.M.K.P. Taylor ◽  
K. Ishii ◽  
Y. Urata
Keyword(s):  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Lean Burn ◽  
Stratified Charge ◽  
Flame Development

The effect of the stroke-to-bore ratio on combustion, heat transfer and efficiency of a homogeneous charge spark ignition engine of given displacement

2000 ◽  
Vol 1 (2) ◽  
pp. 191-208 ◽  
Author(s):  
Z. S. Filipi ◽  
D. N. Assanis
Keyword(s):  
Heat Transfer ◽  
Flame Front ◽  
Turbulent Flame ◽  
Spark Ignition ◽  
Point Of View ◽  
Spark Ignition Engine ◽  
Combustion Heat ◽  
Geometric Point ◽  
Long Stroke ◽  
Homogeneous Charge

This study investigates how the selection of the stroke-to-bore (S/B) ratio affects combustion, heat transfer and overall efficiency in a homogeneous charge spark ignition (SI) engine of a given displacement. Initially, flame front area maps and wall areas in contact with burned gases are examined from a purely geometric point of view, for S/B ratios of 0.7, 1.0 and 1.3. Subsequently, a quasi-dimensional turbulent flame entrainment model is used to quantify the extent to which turbulence versus geometric factors are responsible for the observed combustion, heat transfer and cycle efficiency behaviour, as the S/B ratio varies. Calculations are performed for a range of engine speeds and loads, as well as for operation with 15 per cent exhaust gas recirculation (EGR). Results show that the S/B ratio has a significant effect on both turbulence levels and the geometric interaction of the flame front with the combustion chamber walls. In general, a longer stroke leads to higher thermal efficiency through faster burning and lower overall chamber heat loss. These effects are non-linear, being more dramatic when the S/B ratio is increased from below unity than from above unity. The potential of the long-stroke engine for brake fuel economy improvement can be exploited to the fullest at low speeds, while friction losses gradually diminish it at higher speeds.

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