A semi-implicit numerical scheme for reacting flow. I: Stiff chemistry (Q1287180)

The authors construct an additive semi-implicit projection scheme for simulation of unsteady combustion in two dimensions. The scheme relies on a zero-Mach number formulation of the compressible conservation equations with detailed chemistry. The governing equations are discretized in space using second-order differences, and integrated in time using a semi-implicit approach. Time integration of the evolution equations for species mass fraction, thermodynamic pressure, and density is performed using a semi-implicit, nonsplit scheme that combines a second-order predictor-corrector treatment of convection and diffusion terms, and a stiff integrator for the reaction source terms. Possible extensions of the present scheme to further improve efficiency are also discussed.