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

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

Investigation of the spark ignition enhancement in a supersonic flow

2014 ◽  
Vol 28 (29) ◽  
pp. 1450226 ◽  
Author(s):  
Zun Cai ◽  
Zhen-Guo Wang ◽  
Ming-Bo Sun ◽  
Hong-Bo Wang ◽  
Jian-Han Liang
Keyword(s):  
Ignition Time ◽  
Spark Ignition ◽  
Dominant Factor ◽  
Ignition Process ◽  
Operation Condition ◽  
Flame Kernel ◽  
Operation Conditions ◽  
Key Factor ◽  
Lean Fuel ◽  
Spark Energy

Ethylene spark ignition experiments were conducted based on an variable energy igniter at the inflow conditions of Ma = 2.1 with stagnation state T0 = 846 K , P0 = 0.7 MPa . By comparing the spark energy and spark frequency of four typical operation conditions of the igniter, it is indicated that the spark energy determines the scale of the spark and the spark existing time. The spark frequency plays a role of sustaining flame and promoting the formation and propagation of the flame kernel, and it is also the dominant factor determining the ignition time compared with the spark energy. The spark power, which is the product of the spark energy and spark frequency, is the key factor affecting the ignition process. For a fixed spark power, the igniter operation condition of high spark frequency with low spark energy always exhibits a better ignition ability. As approaching the lean fuel limit, only the igniter operation condition (87 Hz and 3.0 J) could achieve a successful ignition, where the other typical operation conditions (26 Hz and 10.5 J, 247 Hz and 0.8 J, 150 Hz and 1.4 J) failed.

Numerical Analysis on Flame Kernel in Spark Ignition Methane/Air Mixtures

2011 ◽  
Vol 27 (2) ◽  
pp. 363-370 ◽  
Author(s):  
S. Nakaya ◽  
K. Hatori ◽  
M. Tsue ◽  
M. Kono ◽  
D. Segawa ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Spark Ignition ◽  
Flame Kernel

scholarly journals Investigation of the Effect of Electrode Surface Roughness on Spark Ignition

2018 ◽  
Author(s):  
Mohammadrasool Morovatiyan ◽  
Martia Shahsavan ◽  
Mengyan Shen ◽  
John Hunter Mack
Keyword(s):  
Surface Roughness ◽  
Electrode Surface ◽  
High Speed ◽  
Fuel Efficiency ◽  
Spark Ignition ◽  
Ignition Process ◽  
Flammability Limit ◽  
Lean Burn ◽  
Flame Kernel ◽  
Spark Plug

Lean-burn engines are important due to their ability to reduce emissions, increase fuel efficiency, and mitigate engine knock. In this study, the surface roughness of spark plug electrodes is investigated as a potential avenue to extend the lean flammability limit of natural gas. A nano-/micro-morphology modification is applied on surface of the spark plug electrode to increase its surface roughness. High-speed Z-type Schlieren visualization is used to investigate the effect of the electrode surface roughness on the spark ignition process in a premixed methane-air charge at different lean equivalence ratios. In order to observe the onset of ignition and flame kernel behavior, experiments were conducted in an optically accessible constant volume combustion chamber at ambient pressures and temperatures. The results indicate that the lean flammability limit of spark-ignited methane can be lowered by modulating the surface roughness of the spark plug electrode.

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.

Investigation of the Effect of Electrode Surface Roughness on Spark Ignition

2018 ◽  
Author(s):  
Mohammadrasool Morovatiyan ◽  
Martia Shahsavan ◽  
Mengyan Shen ◽  
J. Hunter Mack
Keyword(s):  
Surface Roughness ◽  
Electrode Surface ◽  
High Speed ◽  
Fuel Efficiency ◽  
Spark Ignition ◽  
Ignition Process ◽  
Flammability Limit ◽  
Lean Burn ◽  
Flame Kernel ◽  
Spark Plug

Lean-burn engines are important due to their ability to reduce emissions, increase fuel efficiency, and mitigate engine knock. In this study, the surface roughness of spark plug electrodes is investigated as a potential avenue to extend the lean flammability limit of natural gas. A nano-/micro-morphology modification is applied on surface of the spark plug electrode to increase its surface roughness. High-speed Z-type Schlieren visualization is used to investigate the effect of the electrode surface roughness on the spark ignition process in a premixed methane-air charge at different lean equivalence ratios. In order to observe the onset of ignition and flame kernel behavior, experiments were conducted in an optically accessible constant volume combustion chamber at ambient pressures and temperatures. The results indicate that the lean flammability limit of spark-ignited methane can be lowered by modulating the surface roughness of the spark plug electrode.

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