Weakly-compressible SPH schemes with an acoustic-damper term

Spurious pressure and density waves often occur in weakly-compressible SPH simulations and their propagation and reflection from the boundaries generally lead to large oscillations in the pressure field and noise in the measured loads on solid structures. In the present work this problem is tackled by adding an artificial damping term for acoustic waves in the momentum equation, as theoretically proposed in [1]. Similarly to other diffusive terms previously proposed for weakly-compressible SPH schemes, the present acoustic damper term converges to zero when the particle resolution increases, proving to be numerically consistent. Numerical results show that the acoustic damper is effective in removing the spurious acoustic noise.