A numerical model for simulation of two-phase flows interaction with flexible slender bodies

This paper introduces a fluid–structure interaction (FSI) model for simulation of the coupled dynamics between two-phase flows and elastic slender structures. This model is extended from the early FSI model for single-phase flows by Wang et al. [“A coupled flow and beam model for fluid–slender body interaction,” J. Fluids Struct. 115, 103781 (2022)] to two-phase flows with interfaces of two liquids or free surfaces between gas and liquid. To better capture the interface movement of the two-phase flows and the interaction with the deformable structure, a consistent mass and momentum flux scheme is developed to reduce the spurious oscillation of fluid velocities near the interface, especially in the lower density (e.g., air) region. The proposed model is validated by a series of two-dimensional laboratory experiments of flow impact on a deformable plate, demonstrating that the model has good capabilities of conserving mass and momentum during the process of plate deformation by impulsive flow forces. The model is also applied to the investigation of three-dimensional dam break flow impact on a column of elastic plates. The complex interaction between the plates and the flow is discussed based on the simulation results.