Carbon monoxide concentrations and temperature measurements in a low pressure CH_4–O_2–NH_3 flame

Abstract

Tunable diode laser spectroscopy was used to study a 1-D low pressure flame; CO and H(2)O concentration profiles along the flame axis were recorded. These results are compared to previous measurements by mass spectrometry. Three different methods are checked to infer temperature from observed spectra, and the results are compared with measurements by UV absorption spectroscopy on the OH radical.

Experimental Spectroscopic Studies of Carbon Monoxide (CO) Fluorescence at High Temperatures and Pressures

“…In contrast to physical probes inserted in the flow (thus leading to flow disturbances and possible modifications of the engine operation), laser-based diagnostics are non-intrusive and benefit from high spatial and temporal resolutions. Examples of CO detection in flames by means of laser methods include absorption spectroscopy (with the drawback of a line-ofsight integration of the signal), [1][2][3] spontaneous Raman scattering (point-or 1D-measurements only), 4,5 coherent Raman anti-Stokes scattering (point measurements), [6][7][8] and laser-induced fluorescence. [9][10][11][12][13][14][15][16] Laser-induced fluorescence on CO molecule (CO-LIF) can be performed in the infrared (IR) domain, 16 at the expenses of a high sensitivity to thermal background radiation, or, more classically, in the ultraviolet (UV) spectral range.…”

Laser in situ monitoring of combustion processes

“…An interesting technique for time and spatially resolved temperature measurements is the use of tunable IR diode lasers (TDLs). For measuring temperatures in stationary systems, such as burners, TDL spectroscopy has been applied by scanning over two absorption lines of CO. [17][18][19] In- frared absorption spectra of transient intermediates produced by laser-induced dissociation have been made using boxcar techniques. 2 0 21 The sweep integration technique 2 2 has been shown to yield excellent sensitivity, even with high repetition rates.…”

Chemical Effect of CH4 on NH3 Combustion in an O2/N2 Environment Via ReaxFF

“…They reported the concentration curves of some major species such as CH 4 , H 2 , CO 2 , O 2 , and H 2 O and some nitrogen-containing species such as NH 3 , NO, and NO 2 . Similarly, Rosier et al 12 measured the concentration curves of CO and H 2 O under the same flame conditions using laser spectroscopy. Based on mass spectrometry, absorption spectroscopy, and laser-induced fluorescence techniques, Garo et al 13 studied the ammonia-doped CH 4 /O 2 flames and obtained the spatial distribution curves of some major species and intermediates, including stable intermediates such as HCN and free radicals such as H, O, OH, and CH 3 .…”