NUMERICAL STUDY OF THE COMPRESSIBLE TURBULENT-FLOW IN A LASER CAVITY

This paper presents a numerical study of the structure flow and heal t ransfer in the discharge tube of a high power CO2 laser. A compressibl e turbulent model was developed in connection with simplifying assumpt ions. The resulting set of partial differential equations describing t he flow was solved by means of the PHOENICS code. Several types of the rmal boundary conditions were tested and the numerical results were fo und in a quite good agreement with the experimental data obtained in a previous study. The location of the reattachment point was found high ly correlated with the values of the turbulent energy and the dissipat ion rate of turbulent energy in the entrance section. The size of the recirculation zone and the shock waves created near the exit section o f the nozzle have no significant effect upon the structure flow downst ream of the reattachment point.