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.