The aspects of the numerical modeling of acoustic oscillations of the pressure at large time scales

The influence of properties of first- and second-order accuracy finite-difference schemes and of the grid roughness in the computational domain on the prediction of amplitude-frequency responses of pressure oscillations is investigated within the framework of the problem of steady-state oscillations in a semi-closed channel. It is shown that Godunov-type first-order accuracy scheme underestimates the amplitude of high-frequency oscillations relative to experimental data. Second-order accuracy Lax–Wendroff scheme leads to qualitative coincidence of a trend of amplitude-frequency response with experimental data in terms of the harmonics number even at a relatively coarse discretization of a computational domain.