SPATIALLY RESOLVED FLAMELET STATISTICS FOR REACTION-RATE MODELING

Using two-dimensional laser sheet tomography of Bunsen flames, important spatial statistics relating to premixed turbulent combustion modeling are measured for the first time. The integral length scale of flame wrinkling, evaluated along contours of reaction progress variable (c), is found to be almost constant for all values of c. Its magnitude is measured to be very close to the integral length scale in the unreacted turbulent flow. The flamelet crossing angle distribution in the plane of visualization is found to vary along a c contour reflecting the nonhomogeneity in the flame, but the overall distributions for different c values are approximately the same. The overall mean cosine value is found to be very close to 0.5. Other parameters of interest, including c contours, flamelet crossing lengths, and crossing frequencies, are also examined. © 1990.