Study on ignition temperature of wall-stabilized cool flames

Ignition temperature of premixed cool flames has been studied using wall-stabilized cool flames. A dimethyl ether (DME)-O2 mixture was impinged onto a heated wall and ignited by linearly ramping the wall temperature in the vicinity of cool flame ignition temperature. The instantaneous wall temperature was monitored with a thermocouple, and the HCHO concentration during the ignition of the cool flame was captured using planar laser-induced fluorescence (PLIF) synchronized with the temperature measurement. It is found that the HCHO concentration near the center axis shows an abrupt increase at a certain temperature, which can be defined as the ignition temperature of the cool flame. For the DME/O2 premixed flame, the ignition temperature is found to be 665 K.