Reacting turbulent flow produced by two concentric tubes of finite wall thickness

A numerical model, including a novel numerical procedure, was developed for calculating the heat and mass transfer in reacting turbulent flow produced by two concentric tubes separated by a wall of finite thickness. Equations of motion, energy, and mass, as well as turbulence (described by the k-epsilon model), were expressed in a two-dimensional parabolic form in cylindrical coordinates, assuming steady-state, axial symmetry, and a predominant direction of flow. A combination of the x-r and the x-omega coordinate systems (where r and x are the radial and axial coordinates, respectively, and omega is the normalized stream function) was applied. A hydrogen/air flame was studied assuming immediate local equilibrium. The effects of wall thickness, flow velocities, and initial chemical composition are investigated.