This paper considers the problem of premixed flame blowoff in shear layer stabilized flames, in particular to analyze the velocity scaling of blowoff limits. Analysis of the expression for flame stretch, κ, in a shear layer shows that it consists of two contributions, associated with the shearing and normal strain of the flow. These two contributors lead to flame stretch scalings of S_L/δ and u/L, respectively, where δ and L denote shear layer thickness and characteristic geometric length scale. These terms have different velocity scalings (roughly u~(1/2) and u~1, respectively) and so different blowoff trends can be expected depending upon which term dominates. These predictions are used to interpret a variety of historical bluff body blowoff data in the literature.
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