Influence of travelling waves on the fluid dynamics of a beam submerged in water

Inspired by the use of travelling waves for propulsion mechanisms adopted by many animals and organisms, this paper investigates the mechanism with which travelling waves in beam-like structures induce velocity in a surrounding fluid. This work focuses on the flow induced around the beam tip and provides an experimental characterisation of the phenomena. A test rig equipped with Laser Doppler Anemometry (LDA) is used to investigate the induced fluid velocity and its dependency on the modal response of the beam. Numerical simulations are performed to complement the experimental tests and provide further insight into the fluid-structure interaction. The numerical model also allows for the beam vibration envelope and vibration patterns to be obtained and cor-related with the measured fluid velocity. Several geometrical variations are considered in the analysis over a range of frequencies that encompass resonant responses up to the fourth mode. The results showed that the fluid flow is only marginally affected by the change in the vibration pattern between the first-two resonant mode; the induced fluid velocity and, hence, the thrust are mostly driven by the tip velocity of the beam. & COPY; 2023 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).