Numerical simulation of the nonequilibrium flows in COIL

To our best knowledge, there does not exist any paper in the open literature on detailed steps involved in numerical simulation of the chemical nonequilibrium flows in chemical oxygen iodine laser (COIL). In this paper we aim to provide such details for the relatively simple case of two dimensional flows. Nonequilibrium flows in COIL are simulated by solving the Reynolds averaged Navier-Stokes equations and species continuity equations. Equations are solved using the cell-centred finite volume spatial discretization and four-stage Runge-Kutta time-stepping scheme on structured viscous mesh. The method employs finite-rate chemistry and thermodynamic perfect gas properties for chemical reaction. The stiffness problem of chemical source is overcome by a relaxation iterative scheme. The thickness distribution of some species is obtained for three different inflow boundary conditions. Analyses of the COIL capability are given with different thickness distributions of two species. The results are in good agreement with the conclusion of Paschkewitz et al. concerning species concentrations.