EXTINCTION PROPERTIES OF A PREMIXED LAMINAR FLAME IN OBLIQUE STAGNATION FLOW IN THE REGION OF THE STAGNATION POINT

Two problems are investigated in this work. The first is the determination of premixed laminar flame extinction for general Lewis numbers in an inviscid, steady, two-dimensional normal stagnation flow utilizing a finite element approach. This problem has been investigated previously via the Runge-Kutta method. Results obtained from the finite element approach agreed closely with those stated in the literature. It was found that the finite element method applied to this type of combustion problem was able to capture the steep temperature rise and resolve the reaction zone. Premixed laminar flame extinction in inviscid, steady, oblique two-dimensional stagnation flow in the region of the stagnation point is investigated next. (The formulation of the first problem also applies only to the stagnation region.) This study is via a finite element formulation, and is for general Lewis numbers. Use of the oblique stagnation flow field incorporates the effects of shear as well as extension into the strain field which would be experienced by the flame. It was found that except in the case of Lewis number unity, the effect of shear was to shift the reaction region closer to the wall. A parameter study is performed, and various cases are discussed in detail.