C₂ Production and Excitation in Sooting Flames using Visible Laser Radiation : Implications for Diagnostics in Sooting Flames

Summary, in English

Swan band emission of C₂. which had been produced and excited (d³∏_x←a ³∏_u, Δ v = 0) by focused, tunable, visible laser radiation, was studied in sooting ethylene flames. The C₂signal from the sooting regions of the flames was found to be proportional to the measured volume fractions of soot, indicating laser-vaporized soot to be the source of the signal, and as such it can be used as a diagnostic tool for point measurements of the volume fraction of soot. C₂emission was detected for all incident wavelengths between 485 and 540 nm, with a C₂signal 1–2 orders of magnitude higher when the wavelength was tuned to a C₂ resonance than when tuned to a wavelength between the Swan bands. High concentrations of laser-produced C₂ and emission from C₂Swan bands can, through interference effects, limit the applicability of laser diagnostic techniques to sooting flames.

• Author: Per Erik Bengtsson; Marcus Aldén
• Department/s: Combustion Physics
• Publishing year: 1991-06-01
• Language: English
• Pages: 307-318
• Publication/Series: Combustion Science and Technology
• Volume: 77
• Issue: 4-6
• Links: http://dx.doi.org/10.1080/00102209108951733
• Document type: Journal article
• Publisher: Taylor & Francis
• Keywords: C2 Interference; Laser Diagnostics; Soot Vaporization; Sooting Flames
• Status: Published
• ISBN/ISSN/Other: ISSN: 0010-2202