Improvement of Flame Kernel Growth by Microwave-Assisted Plasma Ignition

  • Joonsik Hwang
  • Wooyeong Kim
  • Choongsik BaeEmail author
Part of the Energy, Environment, and Sustainability book series (ENENSU)


Due to the depletion of petroleum resources and environmental concerns, automobile industry has been developing new engine technologies with acceptable cost range to consumers. Among many new technologies, application of non-thermal plasma ignition system is considered as a promising path to achieve high-efficiency clean gasoline vehicles. In this study, we developed a microwave-assisted plasma ignition using 3 kW, 2.45 GHz magnetron with customized electric components and ignitor. This system was tested in a constant volume combustion vessel to investigate the effects of microwave ejection on ignition kernel growth. High-speed shadowgraph imaging and hydroxyl (OH) radical imaging were carried out under various air-fuel ratio, ambient pressure, and ignition strategy conditions. The in-cylinder pressure measurement was also performed to compare combustion phase between conventional spark and microwave-assisted plasma ignition system. The experimental result showed that the microwave ejection on the thermal plasma created by conventional discharge had a significant improvement on initial flame development. The microwave-assisted plasma ignition system indicated advanced combustion phase with extended lean limit where conventional spark ignition failed to achieve flame propagation. The OH imaging on propagating flame presented much higher intensity with microwave-assisted plasma ignition case. The analysis on light emission spectrum showed 7,000 K higher electron temperature in the plasma created with microwave ejection. This implies that chemical reactions which could not be progressed with conventional spark ignition was enabled with additional non-thermal plasma induced by electro-magnetic wave. On the other hand, however, the enhancement in flame development was decreased under high pressure condition due to lower reduced electric field.


Microwave Non-thermal plasma Constant volume combustion vessel Flame kernel Ignition 


  1. Bittencourt J (2004) Fundamentals of plasma physics. SpringerGoogle Scholar
  2. Ceviz MA, Sen AK, Kuleri AK, Oner IV (2012) Engine performance, exhaust emissions, and cyclic variations in a lean-burn SI engine fueled by gasoline-hydrogen blends. Appl Therm Eng 36:314–324CrossRefGoogle Scholar
  3. DeFilippo A, Saxena S, Rapp V, Dibble R, Chen JY, Nishiyama A, Ikeda Y (2011) Extending the lean stability limits of gasoline using a microwave-assisted spark plug. SAE Technical Paper No. 2011-01-0663Google Scholar
  4. Fridman A (2008) Plasma chemistry, 1st ed. Cambridge University PressGoogle Scholar
  5. Genzale CL, Pickett LM, Hoops AA, Headrick JM (2011) Laser ignition of multi-injection gasoline sprays. SAE Technical Paper No. 2011-01-0659Google Scholar
  6. Hampe C, Bertsch M, Beck KW, Spicher U, Bohne S, Rixecker G (2013) Influence of high frequency ignition on the combustion and emission behavior of small two-stroke spark ignition engines. SAE Technical Paper No. 2013-32-9144Google Scholar
  7. Heywood JB (1988) Internal combustion engine fundamentals. McGraw-HillGoogle Scholar
  8. Hwang J, Kim W, Bae C, Choe W, Cha J, Woo S (2017) Application of a novel microwave-assisted plasma ignition system in a direct injection gasoline engine. Appl Eng 205:562–576CrossRefGoogle Scholar
  9. Hwnag J, Bae C, Park J, Choe W, Cha J, Woo S (2016) Microwave-assisted plasma ignition in a constant volume combustion chamber. Combust Flame 167:86–96CrossRefGoogle Scholar
  10. Ikeda Y, Nishiyama A, Kaneko M (2009) Microwave enhanced ignition process for fuel mixture at elevated pressure of 1 MPa. In: 47th AIAA aerospace sciences meeting including the new horizons forum and aerospace expositionGoogle Scholar
  11. Ju Y, Sun W (2015) Plasma assisted combustion: dynamics and chemistry. Prog Energy Combust Sci 48:21–83CrossRefGoogle Scholar
  12. Luo Y, Alger T, Mangold B, Gingrich J, Kinkler S (2019) Microwave enhancement of lean/dilute combustion in a constant-volume chamber. SAE Technical Paper No. 2019-01-1198Google Scholar
  13. MacLatchy C (1979) Langmuir probe measurements of ion density in an atmospheric pressure air-propane flame. Combust Flame 36:171–179CrossRefGoogle Scholar
  14. Maclatchy C, Clements R, Smy P (1982) An experimental investigation of the effect of microwave radiation on a propane-air flame. Combust Flame 45:161–169CrossRefGoogle Scholar
  15. Oh H, Bae C (2013) Effects of the injection timing on spray and combustion characteristics in a spray-guided DISI engine under lean-stratified operation. Fuel 107:225–235CrossRefGoogle Scholar
  16. Shiraishi T, Urushihara T (2011) Fundamental analysis of combustion initiation characteristics of low temperature plasma ignition for internal combustion gasoline engine. SAE Technical Paper No. 2011-01-0660Google Scholar
  17. Starikovskii AY (2005) Plasma supported combustion. Proc Combust Inst 30:2405–2417CrossRefGoogle Scholar
  18. Starilovskaia SM (2006) Plasma assisted ignition and combustion. J Phys D Appl Phys 39:265–299CrossRefGoogle Scholar
  19. Stockman E, Zaidi S, Miles R, Carter C, Ryan M (2009) Measurements of combustion properties in a microwave enhanced flame. Combust Flame 156:1453–1461CrossRefGoogle Scholar
  20. Sun J, Wang W, Yue Q, Ma C, Zhang J, Zhao X, Song Z (2016) Review on microwave-metal discharge and their applications in energy and industrial processes. Appl Eng 175:141–157CrossRefGoogle Scholar
  21. Szwaja S, Jamrozik A, Tutak W (2013) A two-stage combustion system for burning lean gasoline mixtures in a stationary spark ignited engine. Appl Energy 105:271–281CrossRefGoogle Scholar
  22. Tang H, Pennycott A, Akehurst S, Brace CJ (2015) A review of the application of variable geometry turbines to the downsized gasoline engine. Int J Engine Res 16:810–825CrossRefGoogle Scholar
  23. Thostenson ET, Chou TW (1999) Microwave processing: fundamentals and applications. Compos Part A Appl Sci 30:1055–1071CrossRefGoogle Scholar
  24. Wang Z, Huang J, Wang Q, Hou L, Zhang G (2015) Experimental study of microwave resonance plasma ignition of methane-air mixture in a constant volume cylinder. Combust Flame 162:2561–2568CrossRefGoogle Scholar
  25. Wei H, Zhu T, Shu G, Tan L, Wang Y (2013) Gasoline engine exhaust gas recirculation—a review. Appl Energy 99:534–544CrossRefGoogle Scholar
  26. Wolk B, DeFilippo A, Chen JY, Dibble R, Nishiyama A, Ikeda Y (2013) Enhancement of flame development by microwave-assisted spark ignition in constant volume combustion chamber. Combust Flame 160(7):1225–1234CrossRefGoogle Scholar
  27. Zhao F, Lai MC, Harrington DL (1999) Automotive spark-ignited direct-injection gasoline engines. Prog Energy Combust Sci 25:437–562CrossRefGoogle Scholar
  28. Zhuang Y, Hong G (2014) Effects of direct injection timing of ethanol fuel on engine knock and lean burn in a port injection gasoline engine. Fuel 135:27–37CrossRefGoogle Scholar

Copyright information

© Springer Nature Singapore Pte Ltd. 2020

Authors and Affiliations

  1. 1.Department of Mechanical EngineeringKorea Advanced Institute of Science and Technology (KAIST)DaejeonRepublic of Korea

Personalised recommendations