Arbitrary Lagrangian–Eulerian formulation for fluid–rigid body interaction Original Research Article

A new formulation for two-dimensional fluid–rigid body interaction problems is developed. In particular, vortex-induced oscillations of a rigid body in viscous incompressible flow are studied. The incompressible Navier–Stokes equations are used to describe the motion of the fluid, while it is assumed that the rigid body is mounted on a system consisting of a spring and a dashpot. An arbitrary Lagrangian–Eulerian formulation (ALE) is used in order to account for large boundary motion. A general formulation for the coupled problem is obtained by uncoupling the translation motion of the body from its rotational motion and developing a specific algorithm to efficiently handle the nonlinear dependence of the rotations. This general formulation can be easily applied to multi-body problems. Two numerical examples involving either translations and rotations are presented as an illustration of the proposed methodologies for fluid–rigid body interaction.