Application of “ESCIMO” to the turbulent hydrogen-airdiffusion flame

The ESCIMO theory of turbulent combustion is applied to the hydrogen~air diffusion flame, with the following simplifications: o (1) the reaction is laminar-diffusion controlled within the “fold”; (2) fold properties depend upon age alone, at a given point in the flame; (3) fold properties at “birth” can be deduced by tracing upstream along a line of constant mean fuel-air ratio; (4) fold-birth rate is proportional to entrainment rate, distributed in specified ways across thejet; (5) fold size at birth is proportional to local jet width; and (6) the fold-stretching rate is proportional to the average velocity gradient in the mean flow along the postulated trajectory. Comparisons with the experimental data reported earlier by Kent and Bilger lead to the conclusions: o (i) the agreement in respect of hydrodynamic features is good; (ii) suitable choice of input parameters permits the experimental data for unmixedness tobe fitted fairly well; (iii) allowance for “intermittency” should be made in future work.