In the Wake of Turbulence: Just Keep Swimming…as a Group

Schooling has been shown to be a mechanism utilized by fish to reduce their energy expenditure, particularly when navigating through harsh, turbulent environments. However, the way they interact with each other and the surrounding turbulence to achieve such efficient swimming remains elusive. To uncover the principles utilized by schooling fish when navigating through turbulence, experiments were performed with a school of Giant Danios (Devario Aequipinnatus). By leveraging a unique jet array system, the school was exposed to flow fields with controlled turbulence intensities and energy dissipation rates, while the mean flow and integral length scale were kept constant. Statistics regarding the school size, shape, and kinematics will be presented to quantify how the schooling behavior changes with increasing turbulent kinetic energy. Furthermore, turbulence characteristics of the wake behind the school will be reported to demonstrate how the school modulates the oncoming turbulence.