PIV Analysis of Wake Structure of Real Elephant Seal Whiskers

Seals are able to accurately detect minute disturbances in the ambient flowenvironment using their whiskers, which is attributed to the exceptional capability oftheir whiskers to suppress vortex-induced vibrations in the wake. To explore potential applications for designing smart flow devices, such as high-sensitivity underwaterflow sensors and drag reduction components, researchers have studied how the roleof some key parameters of whisker-like morphology affect the wake structure. Due tothe naturally presented variation in size and curvature along the length of whiskers,it is not well understood how a real whisker changes the surrounding flow and thevortex shedding behavior. This study aims to detail the flow statistics around a realElephant Seal whisker at low Reynolds numbers (i.e. one hundred) using particle image velocimetry in a water channel. Wake flow structures are inspected and comparedbetween two Elephant Seal whiskers (undulating) and a California Sea Lion whisker(smooth), along with idealized whisker-like models. Undulating whiskers significantlychange the mean flow properties and suppress turbulence intensities in the wake region as compared to the smooth whisker at the tested Re. The undulating whiskersare able to create a low turbulence intensity area directly behind the whiskers trailing,vproviding these whiskers with their Vortex Induced Vibration reduction properties