Frequency-domain expression of sound pressure field radiated by monopole source with general moving trajectory

Abstract

Frequency-domain expressions of sound pressure field radiated by moving source were derived successfully only for some special moving trajectories in the literature. In this paper, a frequency-domain expression of sound pressure field radiated by monopole source with general moving trajectory is firstly derived. This expression has a simple mathematical form, where the sound pressure spectrum is written as a Fourier transformation of free-field frequency-domain Green functions along the trajectory. This expression is subsequently verified through theoretical and numerical verification. In theoretical verification, this expression is degenerated into the known analytical solution in each case with special moving trajectories. In numerical verification, the sound pressure spectra calculated via this expression are consistent with those calculated via a time-domain numerical method in cases without known analytical solutions. This expression is finally applied to enable the mode composition beamforming method to localize a rotating source with time-variant rotation speed.