The temporal development of OH-concentration profiles in ignition kernels studied by single-pulse laser induced fluorescence
✍ Scribed by Thomas Berglind; Jan Sunner
- Publisher
- Elsevier Science
- Year
- 1986
- Tongue
- English
- Weight
- 669 KB
- Volume
- 63
- Category
- Article
- ISSN
- 0010-2180
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✦ Synopsis
A freqency doubled dye laser has been used to excite fluorescence from OH-radicals in an ignition kernel in an atmospheric methane/air mixture. The fluorescence was imaged onto a gated and intensified diode array camera. Radial profiles with a spatial resolution of 0.05 mm were obtained from 10 #s to 3 ms after the spark. A transistorized coil ignition unit was used. The OH-concentration profiles grew smoothly during the first ms of the glow discharge phase. Due to the low energy in the initial breakdown the OH-profiles were not distorted by a spark channel and shock wave. At about 1 ms the flame front was seen to separate from the continuing glow discharge. The influence of the gas mixture stoichiometry on the OH-profiles was studied.