A unified modeling method for the rotary enclosed acoustic cavity

Abstract The rotary enclosed acoustic cavity has three common forms, which are conical, cylindrical and spherical cavity. They are widely used in practical production and belong to the category of rotary room acoustics. Therefore, the study of their acoustic characteristics is of great engineering significance. In this paper, a unified analytical model for acoustic characteristics of rotary enclosed cavity with various impedance walls is first established. A three-dimensional (3D) modified Fourier series method is proposed to construct the admissible function of sound pressure. Specifically, the sound pressure function is invariably expressed as a 3D trigonometric series superposition, which includes the multiplication of three cosine functions and six complementary polynomials. The introduction of complementary polynomials can effectively solve the impedance acoustic wall. Based on Rayleigh-Ritz energy method, the acoustic characteristics of the unified analysis model can be obtained. The sound pressure response of the cavity under the influence of different impedance walls is further studied by placing a point sound source inside the acoustic cavity. The accuracy of the unified model is verified by comparing the present results with those obtained by finite element method (FEM) and experiment, and the effect of important parameters on the acoustic characteristics is systematically studied.