Acoustic field characteristic analysis of the rotary acoustic cavity coupled system

Abstract

The rotary acoustic cavity coupled system can be generated in working conditions of aviation, aerospace, ship, machinery, and other fields. The rotary acoustic cavity includes cylindrical, spherical, and conical acoustic cavities, which integrates into the unified analysis model by iso-parametric transformation in finite element method. To study the acoustic field characteristic of rotary acoustic cavity coupled system, a unified analysis model of rotary acoustic cavity coupled system is established: First, the acoustic field characteristic of the coupled system is researched by improved Fourier series method, and the admissible sound pressure function is constructed by three-dimensional modified Fourier series. Then, the acoustic field domain energy functional is established, and the coupled domain energy functional including the coupled potential energy between the sound cavities is introduced to acquire the total energy functional of the coupled system. Finally, the energy equation is solved by Rayleigh–Ritz method, and the natural frequency and corresponding mode of the coupled system are obtained. The unified analysis model demonstrates excellent convergence and accuracy, which is verified by the results of finite element method. Sound pressure responses of the coupled system are obtained by introducing the internal point sound source excitation. The effect of relevant parameters of the coupled system on natural frequency and sound pressure response is investigated, which can provide theoretical guidance for vibration and noise reduction.