A flat flame burner for the calibration of laser thermometry techniques

The design and experimental characterization of a burner is described, which has favourable characteristics for the accurate calibration of a range of optical thermometry techniques. The burner supports stable laminar flames and combines many of the advantages of several widely used burner designs without their disadvantages. It permits the application of point measurement techniques, line-of-sight techniques and planar imaging techniques; trace species, such as metal atoms, can be easily introduced into the flame. The implementation of the burner is described, followed by the presentation of data obtained from coherent anti-Stokes Raman scattering (CARS) measurements and numerical simulations. Spatially resolved measurements were performed over the entire flame profile at three different stoichiometries and factors causing systematic and random errors are described in detail. Measurement errors on mean temperatures were determined to be less than 1%. The shot-to-shot measurement precision was determined to be 3.5–4.0% (FWHM of temperature probability density function). The burner design together with the data presented in this paper can be used for the validation and calibration, respectively, of a variety of combustion thermometry techniques. Complete details of the burner design together with the obtained temperature data will be provided on the World Wide Web. Other researchers intending to validate and calibrate their own laser-based thermometry techniques will be able to cost-effectively reconstruct this burner and adopt the characterization presented here, thus being able to apply it without the need of their own basic validation. The authors are confident that a reconstructed burner, which is applied under the same conditions, will yield the same high level of accuracy and precision as that presented in this paper.