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.