Artificial boundary conditions for numerical simulation of subsonic gas flows

The reflection of gas dynamic waves from artificial computational boundaries used in the simulation of subsonic flows past bodies is analyzed. Nonreflecting boundary conditions for one-dimensional linearized Euler equations are examined in terms of their applicability to full settings. Particular attention is given to flows at low Mach numbers. Techniques are proposed for adapting linear boundary conditions to flow problems with allowance for nonlinearity, two-dimensionality, viscosity, and discretization. The techniques are illustrated by computations of essentially subsonic flows.