Ignition characteristics of premixed cool flames on a heated wall
Autor: | Yiguang Ju, Minhyeok Lee, Yuji Suzuki, Yong Fan |
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Rok vydání: | 2021 |
Předmět: |
Materials science
General Chemical Engineering Analytical chemistry General Physics and Astronomy Energy Engineering and Power Technology 02 engineering and technology 01 natural sciences Temperature measurement law.invention Physics::Fluid Dynamics Chemical kinetics chemistry.chemical_compound 020401 chemical engineering Physics::Plasma Physics law 0103 physical sciences Dimethyl ether Physics::Chemical Physics 0204 chemical engineering 010304 chemical physics Autoignition temperature General Chemistry Cool flame Ignition system Hysteresis Fuel Technology chemistry Extinction (optical mineralogy) |
Zdroj: | Combustion and Flame. 231:111476 |
ISSN: | 0010-2180 |
Popis: | This work examined the cool flame ignition and stabilization on heated walls with different surface reactivities. A premixed mixture of dimethyl ether (DME) and O2 was impinged on a heated wall and the wall temperature was linearly ramped to determine the cool flame ignition temperature. Numerical analyses identify a hysteresis phenomenon in the cool flame ignition and extinction processes, which appears to be primarily governed by the low-temperature reaction kinetics. The formation of HCHO during the cool flame ignition process was monitored using the planar laser-induced fluorescence (PLIF) technique synchronized with instantaneous wall temperature measurements. The data indicated that the HCHO concentration near the wall surface abruptly increased at the ignition of the premixed cool flame. The predicted hysteresis behaviors for cool flame ignition and extinction with a nonlinear folded S-curve and a smoothly stretched S-curve were successfully observed experimentally for the first time ever for lean mixtures. Moreover, the results show that compared with the ignition limits on an inert SiO2 surface, noticeable increases and decreases of the cool flame ignition temperature were observed on Fe and Pt surfaces, respectively. These findings suggest that significant wall chemical effects occur during the cool flame ignition process, based on interactions between the gas phase and surface reactions. |
Databáze: | OpenAIRE |
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