title: From the track to the ocean: Using flow control to improve marine bio-logging tags for cetaceans.
abstract: Bio-logging tags are an important tool for the study of cetaceans, but superficial tags inevitably increase hydrodynamic loading. Substantial forces can be generated by tags on fast-swimming animals, potentially affecting behavior and energetics or promoting early tag removal. Streamlined forms have been used to reduce loading, but these designs can accelerate flow over the top of the tag. This non-axisymmetric flow results in large lift forces (normal to the animal) that become the dominant force component at high speeds. In order to reduce lift and minimize total hydrodynamic loading this work presents a new tag design (Model A) that incorporates a hydrodynamic body, a channel to reduce fluid speed differences above and below the housing and wing to redirect flow to counter lift. Additionally, three derivatives of the Model A design were used to examine the contribution of individual flow control features to overall performance. Hydrodynamic loadings of four models were compared using computational fluid dynamics (CFD). The Model A design eliminated all lift force and generated up to ~30 N of downward force in simulated 6 m/s aligned flow. The simulations were validated using particle image velocimetry (PIV) to experimentally characterize the flow around the tag design. The results of these experiments confirm the trends predicted by the simulations and demonstrate the potential benefit of flow control elements for the reduction of tag induced forces on the animal.
authors.affiliation: Department of Aerospace Engineering, University of Illinois, Urbana, Illinois, United States of America.
authors.forename: Giovani
authors.initials: G
authors.lastname: Fiore
authors.affiliation: Department of Mechanical Engineering, Grove City College, Grove City, Pennsylvania, United States of America.
authors.forename: Erik
authors.initials: E
authors.lastname: Anderson
authors.affiliation: Department of Mechanical Engineering, Grove City College, Grove City, Pennsylvania, United States of America.
authors.forename: C Spencer
authors.initials: CS
authors.lastname: Garborg
authors.affiliation: Mechanical Engineering Department, United States Naval Academy, Annapolis, Maryland, United States of America.
authors.forename: Mark
authors.initials: M
authors.lastname: Murray
authors.affiliation: Scottish Oceans Institute, University of St. Andrews, St Andrews, United Kingdom.|Department of Bioscience, University of Aarhus, Aarhus, Denmark.
authors.forename: Mark
authors.initials: M
authors.lastname: Johnson
authors.affiliation: Biology Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, United States of America.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Moore
authors.affiliation: Pratt School of Engineering, Duke University, Durham, North Carolina, United States of America.|BelleQuant Engineering, PLLC, Mebane, NC, United States of America.
authors.forename: Laurens
authors.initials: L
authors.lastname: Howle
authors.affiliation: Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan, United States of America.
authors.forename: K Alex
authors.identifier: http://orcid.org/0000-0003-3825-8210
authors.initials: KA
authors.lastname: Shorter
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D002591:Cetacea / Q000502:physiology*; D057446:Hydrodynamics; D008954:Models, Biological; D009792:Oceans and Seas; D013550:Swimming / Q000502:physiology*