A compact perfectly matched layer algorithm for acoustic simulations in the time domain with smoothed particle hydrodynamic method

This paper focuses on the development of absorbing boundary conditions and their implementation in the smoothed particle hydrodynamics (SPH) method for wave propagation problems. A compact perfectly matched layer (C-PML) approach is formulated for transient acoustic problems in an infinite space using SPH models with a computational domain of finite dimensions. The proposed approach is based on the concept of fictitious physical damping acting within the additional perfectly matched layers (PMLs) to absorb outgoing waves to practically eliminate the reflection of waves from the boundary of the finite computational domain. To reduce the amount of computations resulting from the layers and improve the computational stability with respect to time, the C-PML algorithm uses the time exponential differencing scheme with small PML domains implemented in an SPH code for transient analyses of waves propagating in acoustic media. Tests of Gaussian pulse sound wave propagation are conducted to demonstrate the effectiveness of the proposed algorithm. The results show that the C-PML algorithm with SPH can absorb the outgoing wave with fewer layers than the conventional PML algorithm. The influence of the thickness of the PML layers, attenuation coefficient, and smoothing length on the C-PML algorithm are analyzed. (C) 2019 Acoustical Society of America.