An experiment of the combustion characteristics with laser-induced spark ignition

• DOI: 10.1007/bf02946126
• Publication Date: 2016-09-22T21:28:30Z
• Authors: Hassan Mohamed; Young -Sung Ko; Keum -Joong Yoon; Suk -Ho Chung
• Keywords: Laser ignition; Minimum ignition energy; SPARK (programming language); Flame speed; Electric spark

The combustion characteristics and minimum ignition energies using laser-induced spark ignition were demonstrated for quiescent methane-air mixtures in an optically-accessible, constant volume combustion chamber. Initial pressure and equivalence ratio as well as spark energy were varied in order to explore the flame behavior with laser-induced spark ignition. Shadowgraphs for the early stages of combustion process showed that the flame kernel becomes separated into two, one of which grows back towards the laser source. Eventually after a short period, the two flame kernels developed into two flame fronts propagating individually, which is unique in laser-induced spark ignition. For a given mixture, lower initial mixture pressure and higher spark energy resulted in shorter flame initiation period and faster flame propagation. The results of minimum ignition energies for laser ignition shows higher values than electric discharge results, however, the difference decreases toward lean and rich flammability limits.