Numerical investigation of the nozzle flow of a vibrationaliy nonequilibrium medium of a CO2 gasdynamic laser

The results are given of a numerical investigation of the nozzle flow of a vibrationaliy nonequilibrium active medium of a CO₂ gasdynamic laser with separate heating of the exciting gas (nitrogen) and subsequent selective excitation (in a region downstream from the throat cross section) of the emitting gas (CO₂). A solution of the problem of two-dimensional flow of vibrationaliy relaxing nitrogen in a Laval nozzle up to the point of injection of the CO₂–He mixture was obtained by the steady-state method using a difference scheme of the third order of precision. The solution of the problem of the flow of a vibrationaliy relaxing CO₂–N₂–He mixture was obtained in the approximation of instantaneous mixing using a through calculation method and a first-order difference scheme. The results are given of a calculation of the flow of nonequilibrium heated nitrogen in a Laval nozzle. A comparison is made of the maximum parameters of a gasdynamic laser with homogeneous selective excitation in the case of equilibrium and nonequilibrium heating of nitrogen. It is shown numerically that a CO₂ gasdynamic laser can be constructed with a pressure in the resonator of ~1 atm