No abstract

In this work, the dynamics of a planing hull in regular head waves was investigated using the Smoothed Particle Hydrodynamics (SPH) meshfree method. The simulation of the interaction of such vessels with wave trains features several challenging characteristics, from the complex physical interaction, due to large dynamic responses, to the likewise heavy numerical workload. A novel numerical wave flume implemented within the SPH-based code DualSPHysics fulfills both demands, guaranteeing comparable accuracy with an established proprietary Computational Fluid Dynamics (CFD) solver without sharpening the computational load. The numerical wave flume uses ad hoc open-boundary conditions to reproduce the flow characteristics encountered by the hull during its motion, combining the current and waves while adjusting their properties with respect to the vessel’s experimental towing speed. It follows a relatively small three-dimensional domain, where the potentiality of the SPH method in modeling free-surface flows interacting with moving structures is unleashed. The results in different wave conditions show the feasibility of this novel approach, considering the overall good agreement with the experiments; hence, an interesting alternative procedure to simulate the seakeeping test in several marine conditions with bearable effort and satisfying accuracy is established.

The presence downstream of a dam of either rigid or erodible obstacles may strongly affect the flood wave propagation, and this complex interaction may lead to further dramatic consequences on people and structures. The open-source Lagrangian-based DualSPHysics solver was used to simulate a three-dimensional dam-break in a closed domain including an oriented obstacle that deflects the flow, thus increasing the complexity of fluid dynamics. By comparing numerical results with experimental data, the effectiveness of the model was evaluated and demonstrated with an extensive sensitivity analysis based on several parameters crucial to the smoothed particle hydrodynamics method, such as the resolution, the boundary conditions, and the properties of the interaction weight function. Charts and summary tables highlight the most suitable conditions for simulating such occurrences in the DualSPHysics framework. The presence of the obstacle, being also an opportunity for observation and study of complex fluid dynamics, opens the way to investigate the fluid interaction with solid objects involved in dam-break events and, possibly, to predict their effect with respect to the relative position between them and the flood and other relevant parameters. Finally, the numerical model presents a good overall agreement.

This work presents a novel numerical framework for dynamic analyses of structure systems within the meshless approach Smoothed Particle Hydrodynamics (SPH) method. The Lagrangian solver DualSPHysics presents several advantages over the widely used Eulerian solvers, dealing with nonlinearities and multiphase phenomena with reasonable numerical stability and reliability. The proposed procedure exploits the mechanical features provided by the Project Chrono library to simulate elastic beams. The modelling procedure is of interest for studying complex soil-, solid-, fluid-structure interactions, involving a system that includes all of the aforementioned phases in a unitary context. The analytical formulation to pass information over to the SPH solver for generating a sub-assembly of rigid stubs and elastic hinges, that will mimic the behavior of a Euler-Bernoulli flexible beam, is presented. The approach is validated against theoretical Euler-Bernoulli solutions: the agreement between the theoretical solutions for the behavior of the flexible beams and the presented model is very good and increases when the number of elements that make up the beam, N , increases. In addition, the behavior of the flexible beam thus created in the SPH environment is validated considering a sensitivity analysis based on several parameters, such as the model resolution (initial interparticle distance) and the number of elements. COMPDYN 2021 8 th ECCOMAS Thematic Conference on Computational Methods in Structural Dynamics and Earthquake Engineering M. Papadrakakis, M. Fragiadakis (eds.

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