Rapid prediction of oblique incident wave field in sea ice acoustic waveguide

This paper proposes a semi-analytical ice acoustic guided wave field prediction method for the directional excitation of sub-ice acoustic sources. The one-dimensional finite element algorithm is used to realize the time-domain deduction of the strain field in ice from the excitation of underwater acoustic sources, taking into account the acoustic energy conversion at the fluid-solid coupling interface. The acoustic waveguide leakage modal dispersion curve of the sea ice is then used to derive the excitation analytically. A rapid prediction of the wave field in sea ice is completed according to the displacement time course of the modal elastic guided wave propagation at a given distance and depth. Comparison with other numerical methods shows a significant improvement in computational speed of three orders of magnitude for the same model conditions at low frequencies, significantly reducing computational time and storage requirements while maintaining computational accuracy. Compared to traditional finite element methods, this method effectively overcomes the limitation that the computational cost increases rapidly with increasing propagation parameters (e.g. horizontal distance and operating frequency), and is particularly suitable for high-frequency and long-distance propagation conditions.