title: A fish perspective: detecting flow features while moving using an artificial lateral line in steady and unsteady flow.
abstract: For underwater vehicles to successfully detect and navigate turbulent flows, sensing the fluid interactions that occur is required. Fish possess a unique sensory organ called the lateral line. Sensory units called neuromasts are distributed over their body, and provide fish with flow-related information. In this study, a three-dimensional fish-shaped head, instrumented with pressure sensors, was used to investigate the pressure signals for relevant hydrodynamic stimuli to an artificial lateral line system. Unsteady wakes were sensed with the objective to detect the edges of the hydrodynamic trail and then explore and characterize the periodicity of the vorticity. The investigated wakes (Kármán vortex streets) were formed behind a range of cylinder diameter sizes (2.5, 4.5 and 10 cm) and flow velocities (9.9, 19.6 and 26.1 cm s(-1)). Results highlight that moving in the flow is advantageous to characterize the flow environment when compared with static analysis. The pressure difference from foremost to side sensors in the frontal plane provides us a useful measure of transition from steady to unsteady flow. The vortex shedding frequency (VSF) and its magnitude can be used to differentiate the source size and flow speed. Moreover, the distribution of the sensing array vertically as well as the laterally allows the Kármán vortex paired vortices to be detected in the pressure signal as twice the VSF.
authors: Department of Mechanical Engineering, University of Bath, Bath BA2 7AY, UK l.chambers@bristol.ac.uk.
authors: L D
authors: LD
authors: Chambers
authors: Whitney Laboratory for Marine Bioscience, University of Florida, St Augustine, FL 32080, USA.
authors: O
authors: O
authors: Akanyeti
authors: Department of Informatics, University of Verona, 37134 Verona, Italy.
authors: R
authors: R
authors: Venturelli
authors: Centre of Biorobotics, Tallinn University of Technology, 12618 Tallinn, Estonia.
authors: J
authors: J
authors: Ježov
authors: Department of Mechanical Engineering, University of Bath, Bath BA2 7AY, UK.
authors: J
authors: J
authors: Brown
authors: Centre of Biorobotics, Tallinn University of Technology, 12618 Tallinn, Estonia.
authors: M
authors: M
authors: Kruusmaa
authors: Department of Informatics, University of Verona, 37134 Verona, Italy.
authors: P
authors: P
authors: Fiorini
authors: Rhine-Waal University of Applied Science, 47533 Kleve, Germany.
authors: W M
authors: WM
authors: Megill
mesh_terms: D000818:Animals; D040761:Biomimetic Materials; D005399:Fishes / Q000502:physiology*; D057446:Hydrodynamics; D053403:Lateral Line System / Q000502:physiology*; D008953:Models, Anatomic; D011312:Pressure
keywords: Kármán vortex street; aquatic navigation; artificial lateral line; pressure sensing; three dimensional