Vortex formation with a snapping shrimp claw

Article English OPEN
Hess, D. ; Brücker, C. ; Hegner, F. ; Balmert, A. ; Bleckmann, H. (2013)

Snapping shrimp use one oversized claw to generate a cavitating high speed water jet for hunting, defence and communication. This work is an experimental investigation about the jet generation. Snapping shrimp (Alpheus-bellulus) were investigated by using an enlarged transparent model reproducing the closure of the snapper claw. Flow inside the model was studied using both High-Speed Particle Image Velocimetry (HS-PIV) and flow visualization. During claw closure a channel-like cavity was formed between the plunger and the socket featuring a nozzle-type contour at the orifice. Closing the mechanism led to the formation of a leading vortex ring with a dimensionless formation number of approximate ΔT*≈4. This indicates that the claw might work at maximum efficiency, i.e. maximum vortex strength was achieved by a minimum of fluid volume ejected. The subsequent vortex cavitation with the formation of an axial reentrant jet is a reasonable explanation for the large penetration depth of the water jet. That snapping shrimp can reach with their claw-induced flow. Within such a cavitation process, an axial reentrant jet is generated in the hollow cylindrical core of the cavitated vortex that pushes the front further downstream and whose length can exceed the initial jet penetration depth by several times.
  • References (10)

    1. Volz P (1938) Studien u¨ ber das ''Knallen'' der Alpheiden. Z. Morphol. Ukol Tiere 34, 272-316.

    2. Brooks WK, Herrick FH (1891) The embryology and metamorphosis of the Macroura; Mem. Natl Akad Sci Washington 5 319-576

    3. Versluis M, Schmitz B, von der Heydt A, Lohse D (2000) How snapping shrimp snap: Through cavitating bubbles. Science 289, 2114-2117.

    4. Herberholz J, Schmitz B (1999) Flow visualisation and high speed video analysis of water jets in the snapping shrimp (Alpheus heterochaelis). J Comp Physiol A 185: 41-49

    5. Vogel S (1996) Life in Moving Fluids: The Physical Biology of Flow, Princeton University Press; ISBN-13: 978-0691026169

    6. Gharib M, Rambod E, Shariff K (1998) A universal time scale for vortex ring formation. J Fluid Mech. 360, 121-40.

    7. Dabiri JO, Gharib M., (2005) Starting flow through nozzles with temporally variable exit diameter. J Fluid Mech. 538:111-36; doi:10.1017/ S002211200500515X

    8. Arndt REA (2002) Cavitation in vortical flows. Annual Rev Fluid Mech 2002. 34:143-75; DOI: 10.1146/annurev.fluid.34.082301.114957

    9. Dabiri JO (2009) Optimal Vortex Formation as a Unifying Principle in Biological Propulsion; Annual Rev. Fluid Mech. 41:17-33.; 10.1146/annurev.- fluid.010908.165232

    10. Belyakov GV, Filippov AN (2005) Cavitating Vortex Generation by a Submerged Jet. Journal of Experimental and Theoretical Physics, 2006, Vol. 102, No. 5, pp. 862-868; ISSN: 1063-7761 (Print) 1090-6509 (Online)

  • Related Research Results (2)
  • Similar Research Results (1)
  • Metrics
    No metrics available
Share - Bookmark