Discussion of a Wrinkled Laminar Flamelet Model in a Diffusion Flame in Grid Turbulence

The temperature has been measured in a field in which laminar hydrogen (6.0 m/s at the center of a burner exit) was injected into a co-flowing air stream (6.0 m/s) with some kinds of grid turbulence. It is shown that the ratio of a laminar flame length to the turbulent one is proportional to the turbulent Reynolds number, Re., (integral scale is considered a characteristic length) in the measured extent (Re_l≤ 1 000), and therefore that the integral scale of a reactant flow is an important parameter for the flames in this paper. The width of a flame displacement is estimated from the temperature profiles when the flame is assumed to be a wrinkled laminar flamelet. The width is also measured directly by a flow visualization method. Both the widths obtained by the two different methods agree well with each other. This fact indicates that the turbulent flame in this paper can be treated as a wrinkled laminar flamelet.