Cantilever in the Wake of the Cube

Simulation of the fluid/structure interaction that dominates the dynamics of these flows poses a formidable challenge to even the most advanced numerical techniques, and is currently at the forefront of ongoing work in computational fluid dynamics. A major challenge in the implementation of any non-boundary conforming methodology is the establishment of the relation between the Lagrangian coordinates of the body and the underlying Eulerian grid and the imposition of boundary conditions.

Understanding the vibration of an inverted cantilever in the wake of a bluff body.

An inverted cantilever mounted at the wake of a square cylinder was simulated. Initially, the cantilever vibrates with the frequency of vortex shedding from the cube with moderate amplitude oscillation. Later this regime suddenly change with much more amplidude of oscillations and twice smaller frequency.

Contours of instantaneous out-of-plane vorticity show the cantilever changing to a lower frequency after a transient period.

The simulation reveals complex fluid-structure interaction in wake-induced vibration.