Dynamics of plasma generated by the dual-pulse laser in a supersonic flow was studied numerically. The mathematical model includes species, momentum, electronic, vibrational and translational energy equations for the multicomponent ionized air. The model examines temporal dynamics of the formed air plasma and how it affects the drag, pressure signature and vorticity generation in a supersonic flow around a wedge. We observed that nonequilibrium plasmas is more effective in the drag reduction compared with the simultaneous thermal energy addition. The maximum drag reduction of around 50% and the maximum drag coefficient reduction of 30% was attained through the dual-pulse laser energy deposition. Variation of the plasma spot orientation did not significantly influence the drag reduction. We suggested that the surface pressure changes were not controlled by the vorticity generation but occurred due to the density changes and the formation of the low-density plasma spot.

Shell models of turbulence were used to study the effect of isotropic turbulence on the refractive index spectrum for the case of a plane wave beam propagation through turbulent flow.Existing theories of the 1D and 3D temperature spectra were shown to be inaccurate in the dissipative range of the spectrum due to unresolved scales at high Reynolds numbers. The shell model explaining the buoyancy driven turbulence was chosen as a tool to consider density changes with temperature and resolve all the range of wavenumbers up to the Kolmogorov's scale. The physical nature of the Hill bump (increase of the slope of the energy spectrum), observed in the transition region between inertial-convective and viscous-diffusive parts of the cascade was

This paper describes a computer-aided modeling technique which determines geometric information of a burning propellant grain. This allows the user to readily obtain plots of burn a r e a , burn volume, moments of inertia, motion o f the center of gravity, and other geometric data a s a function of burn distance. This data may be used in subsequent ballistic analyses. This burn analysis uses the features of a more generat program, GEOMOO~.

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