Numerical Simulation of Supersonic Flow CO Chemical Laser Solving Navier-Stokes Equations

Abstract

The flow field of a supersonic flow CO chemical laser is simulated solving two-dimensional Navier-Stokes equations, and the effects of viscosity, shock waves and the mixing process on the small signal gain coefficients are studied. The calculated flow pattern agrees very well with the chemiluminescence from the laser cavity which was observed previously. Both the calculation and the experiment show that the O₂ streams and the dissociated CS₂ streams collide with each other at the nozzle exits, generating oblique shock waves. It is also shown that mixing of the O₂ streams and the dissociated CS₂ streams is significantly slow, and the temperature and gain distributions in the mixing layer are strongly influenced by the shock waves and expansion waves. The calculated distributions of the small signal gain coefficients along the flow agree fairly well with the measured values in the region near the nozzle exits where the three-dimensional effects are relatively weak.