Session: 4.1.1 - Interactions in Bio-Inspired Propulsion

Paper Number: 158217

158217 - Hydrodynamic Interactions and Performance Enhancement in Stingray Schools 

Abstract: 

Stingrays differ from other fish that have multiple fins, such as pelvic fins and dorsal or anal fins, which interact with the surrounding fluid environment. Instead, stingrays use a single, disk-shaped fin to perform undulatory locomotion for forward movement. In this work, a computational approach is used to study the hydrodynamic interactions between a pair of stingrays arranged in various vertical staggered formations. The stingray’s body motion is based on biological experiment measurements, featuring a traveling wave in the chordwise direction and an amplitude change in the spanwise direction of the fin. The undulation motion is achieved by applying a wavelength of 0.75 body lengths (BL) during swimming. To study the effect of schooling, we evaluate the hydrodynamic performances of the trailing fish in different downstream locations relative to the leader. We use an in-house incompressible Navier-Stokes equation flow solver that employs a topological local mesh refinement technique and an immersed boundary method to analyze the schooling performances and the wake structure of the stingray schools. The Reynolds number is set at 4000 and the Strouhal number is set at 0.46. Performance enhancements achieved by the stingray models through schooling will be documented, along with the discussion of underlying mechanisms associated with the changes in wake topology and surface pressure contours. The findings from this study will pave the way for new studies of schooling interactions, particularly in understanding how interactions affect the added-mass mechanism in undulatory motion. Additionally, these results will offer biologists valuable insights into the schooling behavior of undulating rays and provide robotic scientists with new information to inform the design of bio-inspired aquatic unmanned vehicles.

Presenting Author: Zihao Huang University of Virginia

Presenting Author Biography: Zihao is a research associate whose main interests are in bio-inspired flow, including fluid-structure interactions, bio-propulsion hydrodynamics, flow sensing, and fish schooling mechanisms. He finished his Ph.D. work in the Flow Simulation and Research Group at the University of Virginia.