Calculation of axisymmetric turbulent confined diffusion flames

A solution algorithm based on fully coupled solution of the time-averaged Navier-Stokes equations is developed for the calculation of turbulent reacting flows. The governing elliptic partial differential equations are discretized by finite differences, and the nonlinear algebraic equations are solved by a block-implicit algorithm employing Newton's method and sparse-matrix techniques. Calculations have been made of a confined turbulent diffusion flame. Turbulence is represented by the k-epsilon model, and the chemical reaction is assumed to occur in one step at an infinite rate, controlled by the mixing of fuel and oxidant streams. It is demonstrated that the strategy of coupled solution is rapidly convergent even in the presence of significant density variations. Calculations with finite difference grids as large as 80 x 100 have been made successfully in modest computer time and with modest storage. The calculations are compared with experimental data.