Numerical Analysis on the Reaction Zone Structure of a Supersonic Flow CO Chemical Laser

抄録

The cavity flow field of a supersonic flow CO chemical laser is simulated numerically and the effects of the nozzle boundary layers, the cavity boundary layers and the mixing process on the laser performance are studied. The thin shear layer approximation is applied to the mixing region and the resulting equations are solved by the Crank-Nicolson predictor-corrector method. The numerical results show that the development of the mixing layer in the downstream direction is very gradual. The small signal gain coefficient begins to decay at a location where the mixing layer is still a small portion of the total flow width. The predicted distributions of the averaged gain along the flow agree fairly well with the experiment. It is clearly demonstrated that the presence of the boundary layers and the magnitude of the wall catalysis play decisive roles in determining the laser performance.