Quantitative volumetric laser absorption imaging of methane and temperature in flames utilizing line-mixing effects

A mid-infrared volumetric laser absorption imaging technique was developed for quantitative three-dimensional measurements of methane concentration and temperature in combustion flows. The spectroscopic method utilizes temperature-dependent collisional line mixing amongst a cluster of rovibrational transitions of the R(15) maniold of the v3 asymmetric stretch band of methane. Notably, line mixing effects are shown to increase sensitivity of the ratiometric thermometry, and a first-order model enables quantitative inference of species. 3D volumetric imaging is demonstrated experimentally on a methane-oxygen laminar flame doublet (更多