3-DIMENSIONAL MIXING REACTING ZONE STRUCTURE IN A SUPERSONIC-FLOW CHEMICAL OXYGEN-IODINE LASER/

The flow field of a supersonic flow chemical oxygen-iodine laser is si mulated by solving three-dimensional Navier-Stokes equations and the e ffects of the mixing/reacting zone structure on the resulting gain reg ion are studied. It is assumed that the flow is laminar and the water vapor condensation due to the supersonic cooling is ignored. A chemica l kinetic model encompassing 21 chemical reactions and 10 chemical spe cies is used to determine the chemical composition of the gas mixture. The present results demonstrate that a pair of contrarotating vortice s generated behind the I? jet greatly enhances the mixing and the simu ltaneous chemical reaction to produce the excited iodine atom with the singlet oxygen. In the present calculation, the small signal gain coe fficient is overestimated to some extent as compared with the experime ntal one. It is thought that the overestimation is caused by the imper fect chemical kinetic model as well as by ignoring the water vapor con densation and the boundary layers on the upper and lower wall in the p resent calculation.