On the regimes of underwater explosion for a submerged slender structure by pulsating bubble

• Three regimes: near-, middle- and far-fields are proposed according to the degree of structural global response by an underwater explosion bubble.
• A scaling law for demarcating the three regimes quantitatively is yielded.
• Quantitative criterion of the three regimes is presented along with the regime diagrams for typical submarines.
• Global response features of typical submarines in different regimes are provided.

Three regimes: near-, middle- and far-fields of underwater explosion are proposed in this study aiming at providing an overview on the responses of submerged slender structure by pulsating bubble. In the near-field, the material starts to yield, thus leading to structure breakdown immediately; remarkable structural global elastic deformation occurs in the middle-field as well as substantial movement; and a structure moves as a rigid body with negligible deformation for the far-field. Equivalent dimensionless parameters are obtained by two different dimensional analysis methods, among which a dominant similarity parameter is found out. Thus, a scaling law providing us with a relation between structural global response and the dominant similarity parameter is yielded, which can be used for demarcating the three regimes quantitatively. To demonstrate, three models corresponding to typical submarine parameters are performed in the case studies. Quantitative criterion of the three regimes is presented along with the regime diagrams. The structural global response features such as the deformation and maximal acceleration/speed of different regimes are provided as well.