Experiments into the Flame Kernel Development in High Swirl Production Spark Ignition Engines

1999 ◽  
Author(s):  
R. Ancimer ◽  
H. Jaaskelainen ◽  
J. Wallace
Keyword(s):  
Spark Ignition ◽  
Spark Ignition Engines ◽  
Kernel Development ◽  
Flame Kernel

Discharge Characteristics of Current Boosted Spark Events Under Flow Conditions

2017 ◽  
Author(s):  
Xiao Yu ◽  
Zhenyi Yang ◽  
Shui Yu ◽  
Mark Ives ◽  
Ming Zheng
Keyword(s):  
Flow Velocity ◽  
Discharge Current ◽  
Gas Flow ◽  
Spark Ignition ◽  
Current Level ◽  
Flow Conditions ◽  
Kernel Development ◽  
Flame Kernel ◽  
Spark Plasma ◽  
Gas Flow Velocity

With the advancement of spark ignition engines, lean or diluted in-cylinder charge is often used to improve the engine performance. Enhanced in-cylinder charge motion is widely applied under such conditions to promote the flame propagation, which raise challenges for the spark ignition system. In this work, the spark discharging process is investigated under different flow conditions via both optical diagnosis and electrical measurement. Results show that the spark plasma channel is stretched under flow conditions. A higher discharge current can maintain the stretched spark plasma for a longer duration. Re-strikes are observed when the spark plasma is stretched to a certain extent. The frequency of re-strikes increases with increased flow velocity and decreased discharge current level. The discharge duration reduces with the increased flow velocity. The effects of gas flow on the ignition and flame kernel development are studied in a constant volume optical combustion chamber with premixed lean and stoichiometric methane air mixture. Two spark strategies with low and high discharge current are used for the ignition. The flame propagation speed of both lean and stoichiometric mixtures increases with the increased gas flow velocity. A higher discharge current level retains a more stable spark channel and improves the flame kernel development for both lean and stoichiometric conditions, especially under the higher gas flow velocity of 20 m/s.

An Optical Study of Spark Ignition and Flame Kernel Development Near the Lean Limit at Elevated Pressure

2010 ◽  
Author(s):  
Jaclyn E. Nesbitt ◽  
Seong-Young Lee ◽  
Jeffrey D. Naber ◽  
Rajat Arora
Keyword(s):  
Heat Loss ◽  
Elevated Pressure ◽  
Spark Ignition ◽  
Ambient Conditions ◽  
Kernel Development ◽  
Full Field ◽  
Flame Kernel ◽  
Wide Range ◽  
Flame Development ◽  
Lean Limit

Spark ignition of lean and dilute fuel-air mixtures provides emission reductions of NOx. Furthermore, operation at the lean-dilute limit increases engine efficiency through reduced pumping loses and reduced heat transfer. However, ignition near the lean flammability limit becomes more stochastic and exhibits substantially decreased flame propagation rates. In this work, spark ignition and the subsequent flame kernel development and propagation are studied in a constant volume optical combustion vessel. The vessel provides full field orthogonal and line-of-site optical access via sapphire windows. Additionally, an automated process controller with a versatile gas system enables the creation of a wide range of fuel-air mixtures, including lean and dilute mixtures of hydrocarbons, oxygen, nitrogen, carbon dioxide, and other gases. Ambient conditions including in-chamber temperature and pressure levels, along with dilution conditions, can be set independently. Ignition is provided by an automotive spark plug in the chamber. Optical diagnostics including simultaneous CH* chemiluminescence and shadowgraph imaging are utilized to characterize initial kernel growth and flame development under elevated pressure conditions, from atmospheric to 17.3 bar. Chemiluminescence images are quantified to determine flame intensity and kernel radius to understand the success of initial flame kernel development and propagation. Increasing the pressure yields a slower rate of flame kernel development and propagation, with a thickening flame front, which in turn increases the effects of buoyancy and heat loss. Leaning the mixture can yield unsuccessful kernel development due to heat loss to the large electrode which may cause a failed sustaining of combustion. This knowledge on kernel development near the lean limit benefits the engine community by characterizing the importance of ambient conditions including pressure and mixture properties in sustaining flame growth and propagation.

A Coupled Experimental-Theoretical Model of Flame Kernel Development in a Spark Ignition Engine

1993 ◽  
Author(s):  
D. Yossefi ◽  
M. R. Belmont ◽  
R. Thurley ◽  
J. C. Thomas ◽  
J. Hacohen
Keyword(s):  
Theoretical Model ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Kernel Development ◽  
Flame Kernel

scholarly journals A Numerical Study on Early Stage of Flame Kernel Development in Spark Ignition Process for Methane/Air Combustible Mixtures

2007 ◽  
Vol 73 (732) ◽  
pp. 1745-1752 ◽  
Author(s):  
Shinji NAKAYA ◽  
Kazuo HATORI ◽  
Mitsuhiro TSUE ◽  
Michikata KONO ◽  
Daisuke SEGAWA ◽  
...  
Keyword(s):  
Numerical Study ◽  
Early Stage ◽  
Spark Ignition ◽  
Ignition Process ◽  
Kernel Development ◽  
Flame Kernel ◽  
Combustible Mixtures

4735 Numerical Analysis on flame kernel development in spark ignition process for methane/air combustible mixtures

2006 ◽  
Vol 2006.3 (0) ◽  
pp. 297-298
Author(s):  
Shinji NAKAYA ◽  
Kazuo HATORI ◽  
Mitsuhiro TSUE ◽  
Michikata KONO ◽  
Daisuke SEGAWA ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Spark Ignition ◽  
Ignition Process ◽  
Kernel Development ◽  
Flame Kernel ◽  
Combustible Mixtures
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