OH chemiluminescent radiation from lean hydrogen-oxygen flames

Abstract

The OH radiation intensity in the 3064 Å band, the temperature, and the OH concentration were measured as a function of the height above the face of a premixed H2/O2 flat flame burner. The burner was operated fuel lean at subatmospheric ambient conditions. Examination of possible reaction mechanisms that could produce chemiluminescent OH radiation from these hydrogen-lean flames led to results consistent with those obtained in hydrogen-rich flames. The termolecular rate coefficient for the reaction H+OH+OH→H2O+OH* was found to be (2.3±0.9) × 10−32 cm6 molecules−2 · sec−1. The value represents an upper bound for the rate coefficients of the reactions which might contribute to the excitation of OH.