Experimental Study of OH*, CHO*, CH*, and C₂* Radicals in C₂H₂/0₂ and C₂H₂/O₂/Ar Flames in a Closed Chamber

Abstract

An experimental study of OH*, CHO*. CH* and C2* radicals in excited electronic states present in C₂H₂/O₂ and C₂H₂/O₂/Ar flames was carry out. Measurements of natural emissions of these species as a function of time were obtained for several combustion processes in a closed chamber. The emission times of all radicals for both C₂H₂ sol;O₂ and C₂H₂/O₂/Ar flames were found to decrease with the increase of φ from 0·30 to 0·68 and were almost the same φ = 0·68, φ = l·00 and φ = 1·62. CH*. The C₂* production efficiencies were almost constant in the range to φ > 0·30, while the production efficiencies of OH^* and CHO^* radicals were reduced as φ increased. The addition of argon to increase the total initial pressure had practically no effect on the chemiluminescences of radicals, except for the fuel-lean combustion (φ = 0·30), in which the production efficiencies of excited radicals was reduced.

Keywords:

• acetylene
• combustion
• excited radicals
• closed chamber

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Notes on contributors

CELSO A. BERTRAN

Phone; 55-19-788-3)34, FAX: [phone], e-mail: [email protected]