Effects of mixture fraction on edge-flame propagation speeds

The propagation speeds (Uedge) of nonpremixed edge-flames were measured as a function of stoichiometric mixture fraction (Zst) and global strain rate (σ) for several fuel/oxidant/diluent combinations using a counterflow slot-jet burner. It was found that for fuel Lewis number (Lef) ≈ 1 and oxidant Lewis number (Leo) ≈ 1 with fixed σ, Uedge increases monotonically with increasing Zst. In contrast, for Lef >1 and Leo ≈ 1 with fixed σ, Uedge...