An investigation of a laminar diffusion flame adjacent to a vertical flat plate burner

Abstract

An analytical and experimental study of a methane diffusion flame in the region adjacent to a vertical flat burner is made. The appropriate boundary layer equations including one-dimensional non-gray non-homogeneous thermal radiation formulated on the basis of the exponential wide-band model are solved by the local non-similarity method to yield the gas species, laminar velocity and temperature profiles inside the diffusion flame boundary layer. It is demonstrated that variable physical properties of the gas mixture have important effects on the flame temperature and structure. The diffusion flame shape and temperature distribution in the boundary layer have also been measured by a Mach-Zehnder interferometer to verify the theoretical results. The peak flame temperature, its location and the temperature profile inside the flame sheet are accurately predicted with the two-equation solutions which, however, underestimate the boundary layer thicknesses. Based on these results, the feasibility of a gray gas radiation model is also explored.