Flexible slender body fluid interaction: Vector-based discrete element method with Eulerian smoothed particle hydrodynamics

Abstract

In this paper Eulerian weakly compressible SPH (EWCSPH) is coupled to the Vector-based discrete element model (V-model) to produce a robust mesh-less SPH-V model for fluid-structure interaction (FSI) applications including thin highly flexible bodies. The V-model, originally proposed as a model for granular structures, is extended herein to model non-linear deformation of a continuum representation of elastic structures. Non-linear static validation tests show that the extended V-model provides an accurate representation for problems involving large deformation. Undamped free vibration tests show the V-model is also accurate for transient problems. The SPH-V model with the immersed boundary method and SPH of Eulerian weakly compressible form is applied to established FSI tests for validation. These are oscillation of a flexible plate in quiescent fluids and flow past a cylinder with a rigidly connected flexible flat plate. The complex flow through flexible valve leaflets representative of flow through deep leg veins is demonstrated. Results thus show the SPH-V model is able to accurately capture complex flow features and also non-linear structural mechanics in fully coupled FSI problems.