Simultaneous measurements of gas temperature, soot volume fraction and primary particle diameter in a sooting lifted turbulent ethylene/air non-premixed flame

Simultaneous, planar measurements of flame temperature (T), soot volume fraction (fv), primary particle diameter (dp) and the derived number density of primary particles (Np) are reported in a well characterized, lifted ethylene jet diffusion flame, both to increase confidence in measurement accuracy and to provide new joint statistics. Planar measurements of temperature were performed using non-linear excitation regime two-line atomic fluorescence (nTLAF) of indium with an improved optical arrangement over those reported previously, and were found to yield good agreement with previous measurements obtained with coherent anti-Stokes Raman spectroscopy (CARS). Planar measurements of soot volume fraction and primary particle diameter were performed using time-resolved laser-induced incandescence (TiRe-LII). On the flame centreline, both the measured values of dp and fv grow with axial distance to peak near to the mid height of the flame. The joint probability density functions (PDF) of the measured T, fv, dp and derived Np were obtained from the two-dimensional images and assessed at 15 locations in the flame (5 radial × 3 axial locations). Strong correlations were found between fv, dp and Np, while they exhibit a moderate correlation with flame temperature. The changes in PDFs with radial and axial locations and the most probable values are also reported.