Smoothed particle hydrodynamics simulation of sound reflection and transmission

Abstract

Mesh-based methods are widely used in acoustic simulations nowadays. However, acoustic problems with complicated domain topologies and multiphase systems are difficult to be described with these methods. On the contrary, Smoothed Particle Hydrodynamics (SPH), as a Lagrangian method, does not have much trouble in solving these problems. The present paper aims to simulate the reflection and transmission of sound waves with the SPH method in time domain. Firstly, the linearized acoustic equations are represented in the SPH form by using the particle approximation. Then, one dimensional sound reflection and transmission are simulated with the SPH method and the solutions are compared with the theoretical results. Finally, the effects of smoothing length and neighboring particle numbers on the computation are discussed. The errors of sound pressure, particle velocity, and change of density show that the SPH method is feasible in simulating the reflection and transmission of sound waves. Meanwhile, the relationship between the characteristic impedance and the reflected waves obtained by the SPH simulation is consistent with the theoretical result.