Measurements of scalar dissipation in a turbulent piloted methane/air jet flame Conference Paper uri icon

abstract

  • The first results from a new experimental facility that combines line-imaging measurements of Raman scattering, Rayleigh scattering, and laser-induced CO fluorescence were presented. Simultaneous single-shot line measurements of major species, temperature, mixture fraction, and the radial component of scalar dissipation were obtained in partially premixed methane/air jet flames (25 vol % CH4, 75 vol % air. The laminar and turbulent flames showed a local minimum in the average scalar dissipation near the stoichiometric mixture fraction. In the turbulent flame, the radial component of the instantaneous scalar dissipation near the stoichiometric condition displayed a lognormal distribution at high values and an exponential distribution at low values. The effect of scalar dissipation on flame structure was examined, based on average species mass fractions doubly conditioned upon mixture fraction and scalar dissipation. The length scale of fluctuations in mixture fraction in the turbulent reaction zone was derived from the measured single-shot radial profiles at each stream-wise location. The length scale for fluctuations in scalar dissipation was < 1 mm of the measured stream-wise locations in the turbulent flame. Original is an abstract.

author list (cited authors)

  • Karpetis, A. N., & Barlow, R. S.

publication date

  • January 2002