Computational analysis of bubble–structure interactions in near-field underwater explosion

The response of underwater structures to a near-field explosion is coupled with the dynamics bubble and surrounding water. This multiphase fluid–structure interaction process investigated in paper using two-dimensional model problem that features yielding collapse thin-walled aluminum cylinder. A recently developed computational framework couples finite volume compressible fluid solver element structural employed. liquid–gas interfaces are tracked embedded boundary level set methods. conservation mass momentum across enforced by solving one-dimensional bimaterial Riemann problems. initial pressure inside varied two orders magnitude different test cases. Three modes discovered, including an horizontal (i.e. one lobe extending towards explosive charge) appears counterintuitive, yet has been observed previous laboratory experiments. Because transition modes, time it takes for structure reach self-contact does not decrease monotonically as increases. velocity fields, dynamics, transient deformation visualized elucidate cause each mode transitions. result suggests that, addition incident shock wave, second pulse resulting from contraction also significant effect on structure’s collapse. phase difference between vibration bubble’s expansion influences Furthermore, clear leading two-way interaction. counter-jet points away surface observed. Compared liquid jets produced bubbles collapsing near rigid wall, this opposite direction.