Numerical Solution of Two-Dimensional Axisymmetric Laminar Diffusion Flames

We apply a detailed chemistry, complex transport combustion model to a two-dimensional, axisymmetric laminar diffusion flume in which a cylindrical fuel stream is surrounded by a coflowing oxidizer jet. Unlike some models in which diffusion in the axial direction is neglected, we treat the fully elliptic problem. A discrete solution is obtained by combining a steady-state and a time-dependent solution method. A time-dependent approach is used to help obtain a converged numerical solution on an initial coarse grid using a flame sheet starting estimate. Grid points are then inserted adaptively and Newton's method is used to complete the problem. We investigate both a confined coflowing and an unconfined coflowing methane-air diffusion flame and comparisons with experimental data are made.