On the observability of the pseudo-Rayleigh waves on submerged cylindrical shells

The field radiated by a transiently responding submerged cylindrical shell is addressed, with the focus on the pseudo-Rayleigh wave A0. The main objective of the study is to offer further insights into the experimentally observed issues with the observability of the A0 wave on certain types of thin shells. The presented analysis employs a semi-analytical methodology based on combining the use of classical methods of mathematical physics with a finite-difference approximation for the resulting structural modes. Two shell materials are considered, steel and duraluminum. The radiated hydrodynamic fields are explicitly imaged, and the A0 wave is analyzed. It is demonstrated that for the steel shell, the A0 wave is much more pronounced and has a much lower attenuation than for the same duraluminum shell, a result that is in agreement with the experimental studies. The shell material density is identified as the most likely primary cause of the observed differences in the radiation of the A0 wave.