Experimental study of temperature and CH radical location in partially premixed CH4/Air coflow flames

The experimental study reported here is part of an ongoing investigation of the exhaust NO(x) emission index (EINO(x)) measured from partially premixed flames. The overall goals of the effort are (1) to contribute to the present understanding of NO(x) formation and destruction in flames and (2) to enable the future design of clean burning practical combustors which take advantage of the partially premixed EINO(x) behavior. The objectives of the present study are (1) to implement a calibrated thin-filament pyrometry (TFP) measurement technique appropriate for use in partially premixed Bunsen flames, (2) to examine the structure of partially premixed coflow CH4/air flames while adding temperature, axial velocity, and CH radical location information to an existing database, and (3) to determine if temperature profiles and CH radical locations at three selected heights within three selected partially premixed flames provide insight into a previously measured exhaust EINO(x) minimum for these flames. (AIAA)