EAPSI: Wake Induced by a Group of Seal Whiskers: Implication to High-sensitivity Underwater Flow Sensors

Turk Jodi C, Painesville OH

Investigators

Abstract

High-sensitivity underwater flow sensors are critical for autonomous underwater vehicles (AUVs) to navigate through dark, cramped, and unstable terrain where vision-based and sonar sensors do not function well. Harbor seals are found to be able to track their prey by capturing even minute disturbance of the ambient water solely by using their whiskers. This is attributed to the exceptional capability of seal whiskers to suppress vortex-induced vibration in the wake flow. This project will conduct flow experiments of seal whiskers at Pohang University of Science and Technology University (POSTECH) in South Korea, under the mentorship of Professor Sang Joon Lee. The collaboration provides flow facilities and equipment to obtain unique data that will enable new insights into the wake structure of multiple seal whiskers and its implication to design high-sensitivity underwater flow sensors. Many researchers have studied the effects of key parameters of the whisker morphology on wake structure with idealized whisker-like models. However, due to the natural variation in length, size and twist along the length of seal whiskers, it is not well understood how a real seal whisker changes wake flow, in particular the vortex shedding. It is also unclear how a group of whiskers with a certain configuration interact with each other to affect the wake properties. Lack of knowledge of the wake structure generated by multiple seal whiskers in a group hinders the capability to design whisker-inspired high-sensitivity underwater flow sensors. The goal of this research is to understand the wake of multiple seal whiskers of various configurations at the Reynolds number similar to which harbor seal whiskers are subject to. Experiments will be conducted in a water tunnel using Particle Imaging Velocimetry (PIV). The results will provide insights of how individual wakes interact with each other and if the interaction is beneficial to suppress the vortex shedding. This research will fill the gap of understanding the wake structure that multiple real seal whiskers create. Ultimately knowledge will be used to develop high-sensitivity underwater flow sensors for AUVs operating in a complex environment. This award, under the East Asia and Pacific Summer Institutes program, supports summer research by a U.S. graduate student and is jointly funded by NSF and the National Research Foundation of Korea.