Prediction of vibro-acoustic radiation from Moving Underwater Cylindrical Shells using the precise integration–equivalent source method

This paper establishes a unidirectional time-domain prediction model for an axially moving cylindrical shell in an ideal fluid to predict its transient vibration and acoustic radiation characteristics. First, Hamilton's principle is employed to derive the governing dynamic equations of the shell, incorporating inertial, centrifugal, and Coriolis forces. The Galerkin method is utilized for spatial discretization, and the time-domain vibration response is solved using the Precise Integration Method (PIM) to obtain the transient surface acceleration. On the structural surface, an acceleration equivalent matching method is proposed. Utilizing the normal surface acceleration as the sole boundary condition, an equivalent relationship between the structural dynamic response and the acoustic equivalent source model is established to construct explicit linear equations, which are solved via regularized inversion to obtain the equivalent source strengths. Subsequently, the convective time-domain Green's function is convolved with the equivalent source strengths to obtain the transient acoustic radiation solution based on Galilean coordinate transformations. Through comparative verification with FEM over a flow velocity range of 0 to 200 m/s, the proposed model exhibits excellent accuracy and robustness. Computational results demonstrate that an increase in flow velocity reduces the radiated sound pressure amplitude and prolongs the waveform period, exhibiting significant Doppler shifts.