Pump-probe strategy for instantaneous 2D detection of CH3in flames using a single laser

• Visualization of the reaction zone of flames using CH radicals as markers is restricted by the low concentration of CH in fuel-lean conditions. To address this, methyl radicals (CH3) are employed as a substitution of CH in premixed methane/air flames. A pump-probe method was adopted with the pump laser photolyzing CH3 and the probe laser detecting the photolyzed CH(X25) fragments. Laser excitation scanswere performed to ensure that the fluorescence detected was from CH only. Visualization of the reaction zone of flames was accomplished by a CH3 photofragmentation laser-induced fluorescence technique in fuel-lean conditions (the equivalence ratio of 0.4), where CH planar laser-induced fluorescence did not work in both laminar and turbulent jet flames. The proposed pump-probe method of CH3 can be used to visualize the reaction zone of hydrocarbon combustion under both fuel-lean and fuel-rich conditions with a superior signal-to-noise ratio.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Maskinteknik -- Energiteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Mechanical Engineering -- Energy Engineering (hsv//eng)

NATURVETENSKAP  -- Fysik -- Atom- och molekylfysik och optik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Atom and Molecular Physics and Optics (hsv//eng)

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