The Other Navy Seals: Seal Whiskers as a Bio-inspired Model for the Reduction of Vortex-Induced Vibrations

Bio-inspired engineering looks to nature for inspiration for new technology or solutions to existing challenges. The Science and Technology research community for the US Navy has utilized bio-inspired research to aid in a variety of design challenges for operation in the ocean environment. One particular model system is the whiskers of seals, which have unique bumps or undulations on their surface that aid in vibration reduction as water passes over them. The modification to the vibration response is of interest for many engineering designs in the marine environment which commonly suffer from the vortex-induced vibration (VIV) that occurs when water flows over a bluff body. The unique morphology of the seal whisker may reduce VIV by disruption of the shed vortices. While vibrations are reduced, a small vibrational signal remains, which provides important sensory input to the seal. This study examines the spectral characteristics of the elicited vibrations from real seal whiskers under various flow conditions and explores the mechanism of their VIV reduction in relation to their geometry utilizing simulations and flow over whisker geometry models.