PREMIXED FLAMES IN STAGNATING TURBULENCE .3. THE (KAPPA)OVER-TILDE-(EPSILON)OVER-TILDE THEORY FOR REACTANTS IMPINGING ON A WALL

Turbulent flames stabilized in a stagnating reactant stream impinging on an adiabatic surface are analyzed on the basis of the k-epsilon-theory. Asymptotic methods are used to describe the flow in each of the three identifiable regions in the flow, with matching requirements providing the boundary conditions for the solutions applicable to each. The flame is assumed to be in the neighborhood of the wall so that reactants are present at the wall at least a fraction of the time. The results with respect to the vigor of the flame and to its extinction characteristics in terms of an extinction Damkohler parameter are in qualitative agreement with an earlier study of flames in opposed reactant streams. Thus as the mean rate of strain decreases the flame becomes more vigorous and its reaction zone assumes positions more remote from the wall. The production of turbulent kinetic energy is found to be significantly influenced by coupling between the mean axial pressure gradient and density inhomogeneities.