An arbitrary Lagrangian-Eulerian method for fluid-structure interactions due to underwater explosions

PurposeThis study aims to evaluate blast loads on and the response of submerged structures. Design/methodology/approachAn arbitrary Lagrangian-Eulerian method is developed to model fluid-structure interaction (FSI) problems of close-in underwater explosions (UNDEX). The fluid part provides the loads for the structure considers air, water and high explosive materials. The spatial discretization for the fluid domain is performed with a second-order vertex-based finite volume scheme with a tangent of hyperbola interface capturing technique. The temporal discretization is based on explicit Runge-Kutta methods. The structure is described by a large-deformation Lagrangian formulation and discretized via finite elements. First, one-dimensional test cases are given to show that the numerical method is free of mesh movement effects. Thereafter, three-dimensional FSI problems of close-in UNDEX are studied. Finally, the computation of UNDEX near a ship compartment is performed. FindingsThe difference in the flow mechanisms between rigid targets and deforming targets is quantified and evaluated. Research limitations/implicationsCavitation is modeled only approximately and may require further refinement/modeling. Practical implicationsThe results demonstrate that the proposed numerical method is accurate, robust and versatile for practical use. Social implicationsBetter design of naval infrastructure [such as bridges, ports, etc.]. Originality/valueTo the best of the authors' knowledge, this study has been conducted for the first time.

Automated summary

This study aims to evaluate the blast loads on and the response of submerged structures. An arbitrary Lagrangian-Eulerian method is developed to model fluid-structure interaction problems. The difference in flow mechanisms between rigid and deforming targets is quantified and evaluated.