Coupled fluid-structure computational methods for aircraft ditching simulations: Comparison of ALE-FE and SPH-FE approaches

This article deals with advanced, coupled numerical approaches for simulating the transient fluid structure-interaction as occurring during aircraft emergency landing on water, i.e. ditching. The structure is discretized using the Finite Element method, while for the fluid domain the Arbitrary Lagrangian-Eulerian and the hybrid Smoothed Particle Hydrodynamics-Finite Element method are employed. First, the structural models are thoroughly validated ensuring differences arising from the use of two software packages to be as small as possible. Secondly, selected benchmark cases of guided ditching experiments are simulated with both numerical approaches and numerical results are compared with experimental data. A good agreement is found for pressure, normal force, and strain time histories. Finally, modeling aspects affecting the results such as the effects of the plasticity computation algorithm, air, and model simplifications are discussed.