Navier-Stokes solutions of high energy laser flows

This paper deals with the application of computational fluid dynamics to the calculation of the supersonic mixing flow fields in the cavities of supersonic diffusion chemical lasers and downstream-mixing gasdynamic lasers. The complete equations of motion of a viscous two-dimensional flow (the Navier-Stokes equations) along with the appropriate finite-rate chemical and vibrational rate equations are solved by means of a time-dependent finite-difference technique. Results are obtained which represent a third generation of steady-flow, continuous wave high energy chemical and gasdynamic laser calculations. In addition, a series of numerical experiments are described which take advantage of the transient results obtained with the time-dependent technique; namely, the effects of intentional unsteady fluctuations in the cavity inlet flow properties are shown to increase the laser gain by more than a factor of two due to enhanced mixing induced by the unsteady flow.