Sufficient stability conditions in the calculations of steady supersonic flows using the marching technique and time-dependent flows with account for viscosity

The sufficient conditions for the stability and monotonicity in calculating supersonic steady flows by means of the marching technique are derived. The sufficient stability conditions are also obtained for constructing the solutions of time-dependent conservation laws with account for viscosity by explicit difference schemes. With increase in the viscosity coefficient, the conditions derived go over continuously from the hyperbolic to the parabolic constraints on the time step.