Temperature Dissipation Measurements in a Lifted Turbulent Diffusion Flame

Abstract

Temperature dissipation measurements have been completed in a lifted turbulent non-premixed propane flame issuing from a converging nozzle at several axial stations and along the centerline. The radial and axial components of the temperature dissipation were measured directly. The assumption of lognor-mality is shown to be a good approximation of the temperature dissipation character in the core of the flame out to r_o. the radius where the mean temperature is at a maximum. Significant deviations from the lognormal distribution are observed on the outer side of the shear layer. The radial and axial components of the dissipation are reasonably isotropic in the region close to the jet's centerline. However, in direct contrast to the results found in nonreacting flows, detailed comparisons of the radial and axial temperalure dissipation profiles in the off-axis region of 0.1 < r/ r_o < 1.3 indicate that there are definite anisotropic and non self-similar characteristics in the temperature dissipation. Furthermore, joint probability density functions between temperature and its dissipation components have shown that they are uncorrelated on axis, yet both negative and positive correlation existed further outward from r_o at all the axial stations measured.