Navier-Stokes Solutions for Chemical Laser Flows. Part I. Cold Flows

This work is part of an overall effort to apply detailed and accurate computational fluid dynamic techniques to the solution of practical high energy laser flows. In particular, the complete Navier-Stokes equations are used to calculate the supersonic laminar mixing flows associated with HF chemical lasers. Multicomponent diffusion is treated in a detailed fashion. Solutions are obtained for 'cold flows', where the effects of chemical reactions and vibrational relaxation are not included. Although such a situation is purely artificial, the results do isolate some of the fluid dynamic aspects of chemical laser flows, and provide a set of data to be compared later with hot flow calculations. These results also lend encouragement that solving chemical laser flows by means of the complete Navier-Stokes equations is feasible. Finally, a set of numerical experiments using four different time-dependent finite-difference schemes show that relatively minor changes in the differencing procedure can lead to major variations in the results. A modification of the well-known MacCormack approach appears to be the best suited for mixing flows associated with chemical lasers.