title: Design and application of a fish-shaped lateral line probe for flow measurement.
abstract: We introduce the lateral line probe (LLP) as a measurement device for natural flows. Hydraulic surveys in rivers and hydraulic structures are currently based on time-averaged velocity measurements using propellers or acoustic Doppler devices. The long-term goal is thus to develop a sensor system, which includes spatial gradients of the flow field along a fish-shaped sensor body. Interpreting the biological relevance of a collection of point velocity measurements is complicated by the fact that fish and other aquatic vertebrates experience the flow field through highly dynamic fluid-body interactions. To collect body-centric flow data, a bioinspired fish-shaped probe is equipped with a lateral line pressure sensing array, which can be applied both in the laboratory and in the field. Our objective is to introduce a new type of measurement device for body-centric data and compare its output to estimates of conventional point-based technologies. We first provide the calibration workflow for laboratory investigations. We then provide a review of two velocity estimation workflows, independent of calibration. Such workflows are required as existing field investigations consist of measurements in environments where calibration is not feasible. The mean difference for uncalibrated LLP velocity estimates from 0 to 50 cm/s under in a closed flow tunnel and open channel flume was within 4 cm/s when compared to conventional measurement techniques. Finally, spatial flow maps in a scale vertical slot fishway are compared for the LLP, direct measurements, and 3D numerical models where it was found that the LLP provided a slight overestimation of the current velocity in the jet and underestimated the velocity in the recirculation zone.
authors.affiliation: SJE Ecohydraulic Engineering GmbH, Viereichenweg 12, Stuttgart 70569, Germany.
authors.forename: J A
authors.initials: JA
authors.lastname: Tuhtan
authors.affiliation: Centre for Biorobotics, Tallinn University of Technology, Akadeemia tee 15A-111, Tallinn 12618, Estonia.
authors.forename: J F
authors.initials: JF
authors.lastname: Fuentes-Pérez
authors.affiliation: Department of Signal Processing, Tampere University of Technology, P.O. Box 553, Tampere FI-33101, Finland.
authors.forename: N
authors.initials: N
authors.lastname: Strokina
authors.affiliation: Centre for Biorobotics, Tallinn University of Technology, Akadeemia tee 15A-111, Tallinn 12618, Estonia.
authors.forename: G
authors.initials: G
authors.lastname: Toming
authors.affiliation: Institute of Water and River Basin Management, Karlsruhe Institute of Technology, Kaiserstraße 12, Karlsruhe 76131, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Musall
authors.affiliation: Institute for Modelling Hydraulic and Environmental Systems, University of Stuttgart, Pfaffenwaldring 61, Stuttgart 70569, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Noack
authors.affiliation: Department of Signal Processing, Tampere University of Technology, P.O. Box 553, Tampere FI-33101, Finland.
authors.forename: J K
authors.initials: JK
authors.lastname: Kämäräinen
authors.affiliation: Centre for Biorobotics, Tallinn University of Technology, Akadeemia tee 15A-111, Tallinn 12618, Estonia.
authors.forename: M
authors.initials: M
authors.lastname: Kruusmaa
mesh_terms: D000818:Animals; D002138:Calibration; D005399:Fishes; D057446:Hydrodynamics; D008962:Models, Theoretical; D055585:Physical Phenomena