Staff Publications

Staff Publications

  • external user (warningwarning)
  • Log in as
  • language uk
  • About

    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

    We have a manual that explains all the features 

    Current refinement(s):

    • help
    • print

      Print search results

    • export

      Export search results

    • alert
      We will mail you new results for this query: keywords==Viscous flow regime
    Check title to add to marked list
    An un-momentous start to life: Can hydrodynamics explain why fish larvae change swimming style?
    Müller, Ulrike K. ; Leeuwen, Johan L. van; Duin, Stephan van; Liu, Hao - \ 2009
    Journal of Biomechanical Science and Engineering 4 (2009)1. - ISSN 1880-9863 - p. 37 - 53.
    Burst and coast - Danio Rerio - Fish larvae - Intermittent swimming - Viscous flow regime - Zebrafish

    In this study, we explore mechanical constraints on the swimming performance of zebrafish larvae (Danio rerio) that might explain why larvae switch from sustained swimming to the more efficient burst & coast as they grow. Two hypotheses have been proposed to explain why young fish larvae perform poorly at burst & coast. First, their initial momentum might be low; second, their drag coefficient might be high. To test the two hypotheses, this study makes a quantitative comparison between experimental observations of swimming fish larvae and a CFD model of a self-propelled fish. The study focuses on larvae of the crucial age and size range in which zebrafish switch swimming style. Our studies show that hatchlings perform poorly not only because they cannot accelerate to a high initial coasting speed and hence do not gain enough initial momentum. But they also suffer higher decelerations while coasting due to a high drag coefficient. Overall, the fivefold difference in coasting distance between hatchlings and older larvae corresponds closely to a threefold difference in the time constant of the speed decay and a threefold difference in initial momentum. Our data also show that swimming speed does not decay exponentially, as predicted by the drag-speed relationship in the viscous flow regime, but hyperbolically, due to flow phenomena developing in the boundary layer during the coast.

    Check title to add to marked list

    Show 20 50 100 records per page

     
    Please log in to use this service. Login as Wageningen University & Research user or guest user in upper right hand corner of this page.