Numerical Examples

To assess the effectiveness of the ghost point solid wall boundary conditions, a number of direct numerical simulations have been carried out. Comparisons between numerical and analytical solutions are made. This permits an evaluation of the fidelity of both the proposed inviscid and the viscous boundary conditions. In all the examples discussed below, dimensionless variables are used. The characteristic scales are as follows:

length scale = Ax = Ay (mesh size) velocity scale = a0 (speed of sound) Ax

time scale = —


density scale = p0 (ambient density) pressure scale = p0a0


Figure 6.13. Pressure contour patterns associated with the reflection of an acoustic pulse by a wall.