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Effects of Spark Discharge Characteristic on Cycle-to-Cycle Variations of Combustion for Lean SI Operation with High Tumble Flow
Technical Paper
2017-32-0111
ISSN: 0148-7191, e-ISSN: 2688-3627
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English
Abstract
It has been shown that lean burn is effective for improving the thermal efficiency of gasoline SI engines. This happens because the reduction of heat loss by decrease of flame temperature. On the other hand, the fuel dilution of the premixed gas makes the combustion speed low, and cycle-to-cycle variations of combustion are increased by excessive dilution, it is difficult to increase the thermal efficiency of the gasoline SI engine. Influence of ignition by spark discharge is considered as a factor of combustion variation, and it is necessary to understand the effects of spark discharge characteristics on the lean combustion process. Spark discharge in the SI engines supplies energy to the premixed-gas via a discharge channel in the spark plug gap which ignites the premixed-gas. The discharge channel is elongated by in-cylinder gas flow and its behavior varies in each cycles. When the discharge channel is elongated, the premixed-gas on the discharge channel increases and the gap resistance increases. As a result, the pattern of the discharge energy supply to the premixed gas by the spark discharge also changes in each cycle. It may affect the lean-burn combustion process. However, the relationship between spark discharge and combustion has not been clarified.
In this study, using an ignition system with 10 ignition coils and an adapter for intensify the tumble flow, we photograph the behavior of the discharge channel with a visualization engine. The relationship between discharge channel length and gap resistance are clarified. Then combustion experiments were carried out, discharge current, discharge voltage and in-cylinder gas pressure were measured at the same time. We investigated the influence of gap resistance on the combustion phase
As a result, there was a correlation between the discharge channel area and the gap resistance. It is possible to estimate the spark discharge channel area from the gap resistance, by measuring the discharge voltage and the discharge current without using the visualization device. When the average gap resistance was more than 45 kΩ , CA 5 became 0 deg.ATDC or less except for 1 cycle. Therefore, it was revealed that combustion was promoted when the discharge channel was stretched and the gap resistance was large.
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Sasaki, K., Jung, D., Yokomori, T., and Iida, N., "Effects of Spark Discharge Characteristic on Cycle-to-Cycle Variations of Combustion for Lean SI Operation with High Tumble Flow," SAE Technical Paper 2017-32-0111, 2017, https://doi.org/10.4271/2017-32-0111.Data Sets - Support Documents
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References
- Takahashi , D. , Nakata , K. , Yoshihara , Y. , Ohta , Y. et al. Combustion Development to Achieve Engine Thermal Efficiency of 40% for Hybrid Vehicles SAE TechnicalPaper 2015-01-1254 2015 10.4271/2015-1-1254
- Yokomori , T Matsuda Research and Development on Super Lean Burn Concept for Gasoline Engines Journal of Society of Automotive Engineers of Japan 70 9 18 24 2016 09
- Shiraishi , T. , Teraji , A. , and Moriyoshi , Y. The Effects of Ignition Environment and Discharge Waveform Characteristics on Spark Channel Formation and Relationship between the Discharge Parameters and the EGR Combustion Limit SAE Int. J. Engines 9 1 171 178 2016 https://doi.org/10.4271/2015-01-1895
- Jung , D. , Sasaki , K. , Sugata , K. , Matsuda , M. et al. Combined Effects of Spark Discharge Pattern and Tumble Level on Cycle-to-Cycle Variations of Combustion at Lean Limits of SI Engine Operation SAE Technical Paper 2017-01-0677 2017 10.4271/2017-01-0677