Review on key issues in centrifuge modeling of flow-structure interaction

Flow-structure interaction has raised significant attention among geotechnical community because it is important for prevention of high-speed flowing geo-disasters. Physical modeling serves as a fundamental tool with which to reveal the disaster-causing mechanism, but such modeling is challenging to perform especially in 1 g model tests because of the complex rheology of flows, transient nature of impact processes and strong nonlinear response of structures. The author thus presents a critical review of the state-of-the-art practices of modeling flow-structure interaction using the centrifuge and discusses several key issues. Hierarchical scaling is useful to guarantee flow similarity in microscale and macroscale, while the scaling of the Brazil nut effect and particle-fluid interaction still questionable in current stage. Flow similarity and structure similarity are equally crucial in the modeling of the flow-structure interaction, which indicates that a coupled modeling method should be encouraged. The Coriolis effect complicates flow regimes and exaggerates or lessens the impact effect of simulated flowing disasters, and it is thus important to investigate the mechanism and magnitude of such an influence. To address the above issues and facilitate in establishing basic scaling laws, robust numerical tools are recommended for experiment design and exploring fundamental mechanisms.