NUMERICAL-SIMULATION OF SUPERSONIC-FLOW CO CHEMICAL-LASER SOLVING NAVIER-STOKES EQUATIONS

The flow field of a supersonic flow CO chemical laser is simulated sol ving two-dimensional Navier-Stokes equations, and the effects of visco sity, shock waves and the mixing process on the small signal gain coef ficients are studied. The calculated flow pattern agrees very well wit h the chemiluminescence from the laser cavity which was observed previ ously. Both the calculation and the experiment show that the 02 stream s and the dissociated CS2 streams collide with each other at the nozzl e exits, generating oblique shock waves. It is also shown that mixing of the O2 streams and the dissociated CS2 streams is significantly slo w, and the temperature and gain distributions in the mixing layer are strongly influenced by the shock waves and expansion waves. The calcul ated distributions of the small signal gain coefficients along the flo w agree fairly well with the measured values in the region near the no zzle exits where the three-dimensional effects are relatively weak.