Hydrodynamic fields induced by the shock response of a fluid-filled submerged cylindrical shell containing a rigid co-axial core

The hydrodynamic fields induced by the response to an external shock wave of a system consisting of a submerged fluid-filled cylindrical shell and a rigid cylindrical co-axial core are considered. The primary focus of the study is on the complexity brought into the interaction by the presence of the core, and on the analysis of the multitude of the respective shock wave propagation and reflection phenomena. It is shown that when the core is small, its overall impact on the interaction is insignificant, although the hydrodynamic patterns observed exhibit some interesting features even in that case. As the radius of the core increases, its effect on the interaction becomes more and more pronounced, with the internal wave pattern eventually becoming dramatically different from what is observed in the no-core case. As a part of this investigation, the exact reasons for the significant reduction of the tensile stress reported for a larger core in earlier studies are identified. Finally, when the core becomes sufficiently large to dominate the internal volume, the fluid between the shell and the core starts to behave as a fluid layer, and exhibits some properties similar to those of a waveguide.