COIL performance model

Abstract

An end to end model was developed to predict the performance of a rotating disk Chemical Oxygen Iodine Laser (COIL). The model includes coupled routines to model the singlet oxygen generator (SOG) including ducting and cold trap, the nozzle, and the laser cavity and resonator. The SOG model is based on a quasi 1D two phase wetted wall approach. It includes an effective resistance chlorine/oxygen mass transfer model, a local basic hydrogen peroxide HO2 diffusion model including property variations both in the flow direction and within the film, thermal analysis for both the liquid and gas phases, and evaluation of O2(1(Delta) ) detachment yield, surface deactivation, and gas phase deactivation. A mass addition routine based on variable specific heat and molecular weight influence coefficients is used to establish nozzle initial conditions. The results of the mass addition calculation are used iteratively to assess SOG stagnation pressure and if necessary SOG calculations are repeated. The primary and secondary streams are then separated into a number of stream tubes. The scale of the primary and secondary stream tubes is determined by the specific mixing scale and their stoichiometries by the initial flows. Mixing is assessed based on an approximate bimolecular diffusion coefficient analysis. Concurrent calculations are made to evaluate the effects of area expansion and chemistry. Once the calculation reaches the mirror location the computations can be performed iteratively with either a roof-top or Fabry Perot resonator to achieve self consistency between the mode characteristics and gain medium. The model is described and representative results presented.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.