Flame Kernel Development and its Effects on Engine Performance with Various Spark Plug Electrode Configurations

2005 ◽  
Author(s):  
Y. G. Lee ◽  
J. T. Boehler
Keyword(s):  
Engine Performance ◽  
Kernel Development ◽  
Flame Kernel ◽  
Spark Plug

Impact of spark plug gap on flame kernel propagation and engine performance

2017 ◽  
Vol 191 ◽  
pp. 311-327 ◽  
Author(s):  
Tawfik Badawy ◽  
XiuChao Bao ◽  
Hongming Xu
Keyword(s):  
Engine Performance ◽  
Flame Kernel ◽  
Spark Plug

Engine performance monitoring using spark plug voltage analysis

1997 ◽  
Vol 211 (6) ◽  
pp. 499-509 ◽  
Author(s):  
H Zhao ◽  
N Ladommatos
Keyword(s):  
Decay Time ◽  
Performance Monitoring ◽  
Effective Means ◽  
Combustion Process ◽  
Engine Performance ◽  
Easy Access ◽  
Flame Kernel ◽  
Voltage Decay ◽  
Spark Plug ◽  
Initial Flame

Spark plug based engine combustion diagnostics have the advantage of simplicity and easy access. Over the years there has been considerable interest in developing and applying spark plug ionization probes to monitor the in-cylinder combustion process. In this paper, alternative approaches are presented using the spark plug as the primary sensor. These methods are based on the analysis of the spark voltage and a secondary high-voltage discharge. A series of experiments have been conducted to evaluate their potential in the measurement of combustion quality and the detection of misfire. It is found that the spark voltage decay time is related to the initial flame kernel development and may be used to detect misfire and deteriorating combustion quality in the initial flame development. The results also show that the analysis of secondary voltage decay time could be an effective means of monitoring the combustion quality and detecting misfire during the main combustion period.

scholarly journals Optical Investigation of a Partial Fuel Stratification Strategy to Stabilize Overall Lean Operation of a DISI Engine Fueled with Gasoline and E30

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 396
Author(s):  
Cinzia Tornatore ◽  
Magnus Sjöberg
Keyword(s):  
Volume Fraction ◽  
Direct Injection ◽  
Combustion Process ◽  
Pilot Injection ◽  
Optical Investigation ◽  
Flame Kernel ◽  
Lean Combustion ◽  
Fuel Stratification ◽  
Spark Plug ◽  
Initial Flame

This paper offers new insights into a partial fuel stratification (PFS) combustion strategy that has proven to be effective at stabilizing overall lean combustion in direct injection spark ignition engines. To this aim, high spatial and temporal resolution optical diagnostics were applied in an optically accessible engine working in PFS mode for two fuels and two different durations of pilot injection at the time of spark: 210 µs and 330 µs for E30 (gasoline blended with ethanol by 30% volume fraction) and gasoline, respectively. In both conditions, early injections during the intake stroke were used to generate a well-mixed lean background. The results were compared to rich, stoichiometric and lean well-mixed combustion with different spark timings. In the PFS combustion process, it was possible to detect a non-spherical and highly wrinkled blue flame, coupled with yellow diffusive flames due to the combustion of rich zones near the spark plug. The initial flame spread for both PFS cases was faster compared to any of the well-mixed cases (lean, stoichiometric and rich), suggesting that the flame propagation for PFS is enhanced by both enrichment and enhanced local turbulence caused by the pilot injection. Different spray evolutions for the two pilot injection durations were found to strongly influence the flame kernel inception and propagation. PFS with pilot durations of 210 µs and 330 µs showed some differences in terms of shapes of the flame front and in terms of extension of diffusive flames. Yet, both cases were highly repeatable.

Ignition System Designed to Extend the Plug Life, and the Lean Limit in a Natural Gas Engine

2003 ◽  
Author(s):  
A. K. Chan ◽  
S. H. Waters
Keyword(s):  
Natural Gas ◽  
Engine Performance ◽  
Ignition System ◽  
Gas Engine ◽  
Natural Gas Engine ◽  
Dc System ◽  
Spark Plug ◽  
Long Duration ◽  
Discharge Duration ◽  
Lean Limit

An ignition system that is based on the alternating (AC) rather than the traditional direct (DC) current in the spark plug discharge has been developed at the Caterpillar Technical Center. This system can generate a long duration discharge with controllable power. It is believed that such an ignition system can provide both a leaner operating limit and a longer spark plug life than a traditional DC system due to the long discharge duration and the low discharge power. The AC ignition system has successfully been tested on a Caterpillar single cylinder G3500 natural gas engine to determine the effects on the engine performance, combustion characteristics and emissions. The test results indicate that while the AC ignition system has only a small impact on engine performance (with respect to a traditional DC system), it does extend the lean limit with lower NOx emissions. Evidences also show the potential of reduce spark plug electrode erosions from the low breakdown and sustaining discharge powers from the AC ignition system. This paper summarizes the prototype design and engine demonstration results of the AC ignition system.

Evaluation of Spark Plug and Timing Configurations on the Fuel Consumption, Combustion Stability, and Emissions of a Large-Bore, Two-Stroke, Natural Gas Engine

2016 ◽  
Author(s):  
Derek Johnson ◽  
Marc Besch ◽  
Nathaniel Fowler ◽  
Robert Heltzel ◽  
April Covington
Keyword(s):  
Natural Gas ◽  
Fuel Consumption ◽  
Combustion Engine ◽  
Engine Performance ◽  
Combustion Stability ◽  
Oxides Of Nitrogen ◽  
Natural Gas Engines ◽  
Fuel Delivery ◽  
Spark Plug ◽  
Trade Offs

Emissions compliance is a driving factor for internal combustion engine research pertaining to both new and old technologies. New standards and compliance requirements for off-road spark ignited engines are currently under review and include greenhouse gases. To continue operation of legacy natural gas engines, research is required to increase or maintain engine efficiency, while reducing emissions of carbon monoxide, oxides of nitrogen, and volatile organic compounds such as formaldehyde. A variety of technologies can be found on legacy, large-bore natural gas engines that allow them to meet current emissions standards — these include exhaust after-treatment, advanced ignition technologies, and fuel delivery methods. The natural gas industry uses a variety of spark plugs and tuning methods to improve engine performance or decrease emissions of existing engines. The focus of this study was to examine the effects of various spark plug configurations along with spark timing to examine any potential benefits. Spark plugs with varied electrode diameter, number of ground electrodes, and heat ranges were evaluated against efficiency and exhaust emissions. Combustion analyses were also conducted to examine peak firing pressure, location of peak firing pressure, and indicated mean effective pressure. The test platform was an AJAX-E42 engine. The engine has a bore and stroke of 0.216 × 0.254 meters (m), respectively. The engine displacement was 9.29 liters (L) with a compression ratio of 6:1. The engine was modified to include electronic spark plug timing capabilities along with a mass flow controller to ensure accurate fuel delivery. Each spark plug configuration was examined at ignition timings of 17, 14, 11, 8, and 5 crank angle degrees before top dead center. The various configurations were examined to identify optimal conditions for each plug comparing trade-offs among brake specific fuel consumption, oxides of nitrogen, methane, formaldehyde, and combustion stability.

Study on the Performance and Exhaust Emissions of Motorcycle Engine Fuelled with Hydrogen-Gasoline Compound Fuel

2012 ◽  
Vol 8 (3) ◽  
pp. 69-81 ◽  
Author(s):  
Chang-Huei Lin ◽  
Li-Ming Chu ◽  
Hsiang-Chen Hsu
Keyword(s):  
Air Pollution ◽  
Performance Test ◽  
Engine Performance ◽  
Combustion Efficiency ◽  
Hydrogen Gas ◽  
Spark Plug ◽  
The People ◽  
Efficient Combustion ◽  
Combustion Technology ◽  
Save Energy

The motorcycle plays an important role in the life for the people of Taiwan. However, the motorcycles’ emissions are the main moving air pollution sources. Therefore, it’s important to develop more efficient combustion technology in order to save energy and reduce air pollution. In this paper, a novel technology of hydrogen-gasoline compound fuel is developed. Hydrogen gas is released from solid state hydrogen storage tank and then mixed with the incoming gasoline. The intake valve in manifold sucks the hydrogen-gasoline compound fuel into the cylinder for combustion. A series of performance test is conducted by motorcycle chassis dynamometers. The results reveal that this technology can increase the power and torque, and decrease fuel consumption per kilo-power due to promote combustion efficiency. In addition, the hydrogen has greater heat value, so the oil temperature and spark plug temperature increase. This technique can reduce CO and HC, but increase CO2 and NOx. The engine performance is improved at rarefied hydrogen-gasoline compound fuel. Therefore, the engine performance with M.J. #98 is better than that with M.J. #110. This technique can achieve energy saving and environment-friendly purpose.

Effect of spark discharge energy scheduling on ignition under quiescent and flow conditions

2020 ◽  
Vol 234 (12) ◽  
pp. 2878-2891
Author(s):  
Zhenyi Yang ◽  
Xiao Yu ◽  
Hua Zhu ◽  
David S-K Ting ◽  
Ming Zheng
Keyword(s):  
Flow Velocity ◽  
High Power ◽  
Cross Flow ◽  
Spark Discharge ◽  
Discharge Process ◽  
Discharge Energy ◽  
Flow Conditions ◽  
Flame Kernel ◽  
Spark Plug ◽  
Spark Energy

The enhancement of the breakdown power during the spark discharge process has been proved to be beneficial for the flame kernel formation process under lean/diluted conditions. Such a strategy is realized by using a conventional transistor coil ignition system with an add-on capacitance in parallel to the spark plug gap in this paper. In practical application, the use of different ceramic material other than aluminum oxide can change the parasitic capacitance of the spark plug, achieving similar effect in terms of rescheduling the discharge energy released during the breakdown phase. Detailed research has been carried out to investigate the effect of the parallel capacitance and the cross flow velocity on the flame kernel formation and propagation process. With the increase in parallel capacitance, more spark energy is delivered during the breakdown phase, while less energy is released during the arc/glow phase. Shadowgraph images of the spark plasma reveal that the high-power spark discharge can generate a larger high-temperature area with enhanced electrically prompted turbulence under quiescent conditions, as compared with that using the conventional transistor coil ignition discharge strategy under the same condition. The breakdown enhanced turbulence of the high-power spark is proved to be beneficial for the flame kernel development, especially with the lean or exhaust gas recirculation diluted combustible mixtures, given that sufficient spark energy is available for the high-power spark strategy to successfully generate the breakdown event. The results of combustion tests under flow conditions reveal that the breakdown enhanced turbulence of the high-power spark tends to be overshadowed by the turbulence generated from the flow field, and both the increase in flow velocity and parallel capacitance contribute to the reduction in discharge duration of the arc/glow phase. Therefore, the benefits brought about by the high-power spark discharge tend to diminish with the intensification of flow velocity.

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