The near-field turbulent structure of double-concentric hydrogen-air j
et diffusion flames, with or without swirl, has been investigated usin
g conditionally sampled, three-component laser-Doppler velocimetry and
coherent anti-Stokes Raman spectroscopy. The turbulent flame zone bec
ame thinner and shifted inward as the mean jet velocity was increased,
whereas swirl created a radial velocity even at the jet-exit plane, t
hereby broadening and shifting the flame zone outward. The probability
-density functions of velocity components, their 21 moments (up to fou
rth order), mean temperature, and root-mean-square temperature fluctua
tion were determined in the near field. The data can be used to valida
te advanced turbulent combustion models.