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Influence of High Frequency Ignition on the Combustion and Emission Behaviour of Small Two-Stroke Spark Ignition Engines
Published October 15, 2013 by Society of Automotive Engineers of Japan in Japan
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The two-stroke SI engine is the predominant driving unit in applications that require a high power-to-weight ratio, such as handheld power tools. Regarding the latest regulations in emission limits the main development area is clearly a further reduction of the exhaust emissions.
The emissions are directly linked to the combustion processes and the scavenging losses. The optimization of the combustion processes, which represents one of the most challenging fields of research, is still one of the most important keys to enhance the thermal efficiency and reduce exhaust emissions. Regarding future emission regulations for small two-stroke SI engines it is inevitable that the emissions of gases causing the greenhouse effect, like carbon dioxide, need to be reduced.
As most small SI engines are carburetted and operate open loop, the mixture formation and the amount of residual gas differs from cycle to cycle . When using conventional ignition systems, the size of the plasma is restricted to the small dimensions of the spark plug gap. In combination with the high flow velocities of small two-stroke SI engines and the variations of the mixture, the cycle-to-cycle variations are very high. Misfiring and delayed combustion lead to high emissions and poor running smoothness, especially at idle speed. Therefore an alternative ignition system was used to enhance the inflammation behavior with a more stable and faster combustion compared to a conventional ignition. At rated power there were improvements in the engine power and also in the engine efficiency due to a better combustion. At idle the most important improvement was the lean misfire limit which could help the fuel efficiency and the reduction of emissions a lot dependent on the field of application of the engine.
CitationHampe, C., Bertsch, M., Beck, K., Spicher, U. et al., "Influence of High Frequency Ignition on the Combustion and Emission Behaviour of Small Two-Stroke Spark Ignition Engines," SAE Technical Paper 2013-32-9144, 2013, https://doi.org/10.4271/2013-32-9144.
- Bertsch , M. , Schreer , K. , Disch , C. , Beck , K. et al. Investigation of the Flow Velocity in the Spark Plug Gap of a Two-Stroke Gasoline Engine using Laser-Doppler-Anemometry SAE Int. J. Engines 5 1 34 41 2012 10.4271/2011-32-0529
- Gegg , T. , Kölmel , A. , & Beck , K. 2010 Combustion Analysis on Small Two-Stroke SI Engines for Handheld Power Tools 2010-32-0062 . SAE Technical Paper
- Hampe , C. , Kubach , H. , Spicher , U. , Bohne , S. , Rixecker , G. Investigations of Ignition Processes using High Frequency Ignition SAE 2013-01-1633 . SAE Technical Paper 2013
- Günther , M. , Tröger , R. , Nicklitzsch , S. , Adolf , M. , Bohne , S. Design Criteria for the Use of Corona Ignition Systems in Combustion Engines IAV congress Berlin 2012
- Agneray , A. Radio Frequency Ignition System. Breakthrough Technology for the Future Spark Ignition Engine SIA congress 2009
- Rixecker , G. , Bohne , S. , Adolf , M. , Becker , M. , Trump , M. , Bargende , M. The High Frequency Ignition System EcoFlash IAV congress Berlin 2012
- Berndt , F. , Rottenkolber , G. , Herweg , R. , Haase , D. , Dieler , T. Lean Burn Combustion for Gasoline Engines: Potential of High Frequency Ignition and High Pressure Injection FKFS congress Stuttgart 2013
- Schenk , M. , Fessler , M. , Wolf , T. , Klaus , B. , Fischer , H. Comparison of the Thermodynamic Potential of Alternative Ignition Systems for SI-Engines IAV congress Berlin 2012