A computational framework for fluid–rigid body interaction: Finite element formulation and applications Original Research Article

This work is concerned with the modelling of the interaction of fluid flow with flexibly supported rigid bodies. The fluid flow considered is governed by the incompressible Navier–Stokes equations and modelled by employing stabilised low order velocity–pressure finite elements. The motion of the fluid domain is accounted for by an arbitrary Lagrangian–Eulerian (ALE) strategy. The rigid body motion, excited by the fluid flow, is restricted by the elastic and damping properties of the supports. For the temporal discretisation the discrete implicit generalised-α method is employed. The resulting strongly coupled set of nonlinear equations is solved by means of a novel partitioned solution procedure, which is based on the Newton–Raphson methodology and incorporates full linearisation of the overall incremental problem. The strong coupling is resolved and optimal convergence of the residuals is achieved. Several numerical examples are presented to demonstrate the robustness and efficiency of the methodology. The examples clearly capture the phenomena of vortex induced oscillations and galloping.