The cellular automata model of sound propagations and its application in structural noise calculations

Abstract

Based on the cellular automata (CA) method and the principle of wave superposition, this study examines a computational technique to analyze the sound radiation characteristics of arbitrary shape structures. The local evolution rule of the one-dimensional (1D) CA model of Y-function was derived from the acoustic wave equation in spherical coordinate, and the relationship between Y-function and sound pressure was used to calculate the sound pressure value. On this basis, the 1D CA model of sound propagation for pulsating sphere source was established, and the superimposed sound field of multiple sphere sources in two-dimensional (2D) space was analyzed. Furthermore, combined with the principle of the wave superposition, the acoustic radiation characteristics of a rectangular piston in three-dimensional (3D) space were discussed, and the feasibility of the proposed method was verified by experiments. Finally, by introducing the finite element method, the calculation method of noise radiated by the 3D structure under external loads was presented, and the radiated sound field of a simply supported beam under loads was analyzed. The results shown that the proposed method could avoid anisotropic updating of cell state variables in the traditional 2D CA model. Moreover, the modeling was simpler, the calculation accuracy and efficiency were also higher. The results calculated by the proposed method matched well with the analytical solutions, experimental results, and numerical results, which indicated the veracity of the calculation method. The proposed method can provide a novel way for noise calculation of engineering structures.