Interaction between an incompressible flow and elastic cantilevers of circular cross-section

• The flow around and deformation of elastic cantilevers are studied.
• Effects of cantilever length and elasticity are studied.
• Onset of synchronisation and frequency of motion vary with cantilever length.
• The wake structure is relatively unaffected in the desynchronised range.
• During synchronisation the proximal part of the wake is strongly affected.

The purpose of this work is to study the deformation of elastic cantilevers due to hydrodynamic forces by coupled fluid–structure interaction simulations. The cantilever is placed in a rectangular duct and the Reynolds number based on bulk velocity and cantilever diameter is 400. Reduced velocities in the range π/4 to 2π are studied, which covers both un-synchronised motion and the initial branch of synchronisation. The cantilever surface is represented by a virtual boundary method which replaces a solid object in flow by additional force distribution to satisfy local boundary condition. The flow field is solved using a Cartesian finite difference code and the deformation of the cylinder a finite element approach using one-dimensional beam elements is used.