FLAME PROPAGATION THROUGH SWIRLING EDDIES, A RECURSIVE PATTERN

Computed flame motion through and between swirling eddies exhibits a m aximum advancement rate which is related to the time duration of flame motion between eddies. This eddy spatial structure effect upon the ap parent turbulent flame speed appears to be similar to the square-root dependence observed in wrinkled flamelet data. The rate-limiting behav ior at one eddy length-scale can be removed by inclusion of smaller ed dies which reside between the larger eddies. This large-eddy, small-ed dy concept yields a recursion relation and repeated functional iterati on can be done to approximate a desired flame speed relation. As an ex ample, an iteration to produce S(T) ln S(T) = u' is given for the rang e of u' observed in liquid flames. Currently, the iteration process is a post-diction of flame speed, but if a universality can be developed , then a predictive theory of turbulent flame propagation might be ach ieved.