Falling balls in a viscous fluid with contact: Comparing numerical simulations with experimental data

We evaluate a number of different finite-element approaches for fluid–structure (contact) interaction problems against data from physical experiments. This consists trajectories single particles falling through highly viscous fluid and rebounding off the bottom tank wall. The resulting flow is in transitional regime between creeping turbulent flows. type configuration particularly challenging numerical methods due to large change domain contact wall particle. In simulations, we consider both rigid body linear elasticity models particles. first case, compare results obtained with well-established Arbitrary Lagrangian–Eulerian (ALE) approach an unfitted moving method together simple common avoidance. For full (FSI) problem contact, use fully Eulerian combination unified FSI-contact treatment using Nitsche's method. higher computational efficiency, geometrical symmetry experimental setup reformulate FSI system into two spatial dimensions. Finally, show three-dimensional ALE computations study effects small perturbations initial state particle investigate deviations perfectly vertical fall observed experiment. are implemented open-source finite element libraries, made freely available aid reproducibility.