Hostname: page-component-7c8c6479df-24hb2 Total loading time: 0 Render date: 2024-03-28T15:45:43.377Z Has data issue: false hasContentIssue false

Ultra-fast escape of a deformable jet-propelled body

Published online by Cambridge University Press:  13 March 2013

G. D. Weymouth*
Affiliation:
Southampton Marine and Maritime Institute, University of Southampton, Southampton, SO17 1BJ, UK
M. S. Triantafyllou
Affiliation:
Center for Ocean Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
*
Email addresses for correspondence: weymouth@mit.edu, G.D.Weymouth@soton.ac.uk

Abstract

In this work a cephalopod-like deformable body that fills an internal cavity with fluid and expels it to propel an escape manoeuvre, while undergoing a drastic external shape change through shrinking, is shown to employ viscous as well as mainly inviscid hydrodynamic mechanisms to power an impressively fast start. First, we show that recovery of added-mass energy enables a shrinking rocket in a dense inviscid flow to achieve greater escape speed than an identical rocket in a vacuum. Next, we extend the shrinking body results of Weymouth & Triantafyllou (J. Fluid Mech., vol. 702, 2012, pp. 470–487) to three-dimensional bodies and show that three hydrodynamic mechanisms must be combined to achieve rapid escape performance in a viscous fluid: added-mass energy recovery; flow separation elimination; and an optimized energy storage and recovery. In particular, we show that the mechanism of separation elimination achieved through rapid body shrinking, coordinated with the mechanism of recovering the initially imparted added-mass energy, is critical to achieving a high escape speed. Hence a flexible, collapsing body can be vastly superior to a rigid-shell jet-propelled body.

Type
Papers
Copyright
©2013 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Anderson, E. J. & Grosenbaugh, M. A. 2005 Jet flow in steadily swimming adult squid. J. Expl Biol. 208, 11251146.CrossRefGoogle ScholarPubMed
Anderson, E. J., Wuinn, W & deMont, M. E. 2001 Hydrodynamics of locomotion in the squid Loligo pealei. J. Fluid Mech. 436, 249266.Google Scholar
Bartol, I. K., Krueger, P. S., Thompson, J. T. & Stewart, W. J. 2009 Pulsed jet dynamics of squid hatchlings at intermediate Reynolds numbers. J. Expl Biol. 212, 15061518.Google Scholar
Childress, S., Spagnolie, S. E. & Tokieda, T. 2011 A bug on a raft: recoil locomotion in a viscous fluid. J. Fluid Mech. 669, 527556.CrossRefGoogle Scholar
Childress, S., Vanderberghe, N. & Zhang, J. 2006 Hovering of a passive body in an oscillating airflow. Phys. Fluids 18, 117103.Google Scholar
Dabiri, J. O., Colin, S. P. & Costello, J. H. 2006 Fast-swimming hydromedusae exploit velar kinematics to form an optimal vortex wake. J. Expl Biol. 209, 20252033.Google Scholar
Daniel, T. L. 1984 Unsteady aspects of aquatic locomotion. Am. Zool. 24 (1), 121134.Google Scholar
Domenici, P., Blagburn, J. M. & Bacon, J. P. 2011a Animal escapology I: theoretical issues and emerging trends in escape trajectories. J. Expl Biol. 214, 24632473.Google Scholar
Domenici, P., Blagburn, J. M. & Bacon, J. P. 2011b Animal escapology II: escape trajectory case studies. J. Expl Biol. 214, 24742494.CrossRefGoogle ScholarPubMed
Domenici, P. & Blake, R. 1997 The kinematics and performance of fish fast-start swimming. J. Expl Biol. 200, 11651178.CrossRefGoogle ScholarPubMed
Forsythe, J. W. & Hanlon, R. T. 1988 Behavior body patterning and reproductive biology of Octopus bimaculoides from California USA. Malacologia 29, 4155.Google Scholar
Gazzola, M., van Rees, W. M. & Koumoutsakos, P. 2012 C-start: optimal start of larval fish. J. Fluid Mech. 698, 517.CrossRefGoogle Scholar
Gosline, J. M. & DeMont, M. E. 1985 Jet-propelled swimming in squid. Sci. Am. 252, 96103.Google Scholar
Hoerner, S. 1965 Fluid Dynamic Drag. Published by the author, Hoerner Fludi Dynamics, Bricktown, New Jersey.Google Scholar
Huffard, C. L. 2006 Locomotion by Abdopus aculeatus (Cephalopoda: Octopodidae): walking the line between primary and secondary defenses. J. Expl Biol. 209, 36973707.Google Scholar
Kanso, E., Marsden, J. E., Rowley, C. W. & Melli-Huber, J. B. 2005 Locomotion of articulated bodies in a perfect fluid. J. Nonlinear Sci. 15, 255289.Google Scholar
Linden, P. F. & Turner, J. S. 2004 Optimal vortex rings and aquatic propulsion mechanisms. Proc. R. Soc. Lond. B 271, 647653.Google Scholar
Margolin, L. G., Rider, W. J. & Grinstein, F. F. 2006 Modeling turbulent flow with implicit LES. J Turbul 7, 127.Google Scholar
Moslemi, A. & Krueger, P. S. 2011 The effect of Reynolds number on the propulsive efficiency of a biomorphic pulsed-jet underwater vehicle. Bioinsp. Biomim. 6, 026001.Google Scholar
Neumeister, H., Ripley, B., Preuss, T. & Gilly, W. F. 2000 Effects of remperature on escape jetting in the squid Loligo opalescens. J. Expl Biol. 203, 547557.Google Scholar
Packard, A. 1969 Jet propulsion and the giant fibre response of Loligo. Nature 221, 875877.Google Scholar
Saffman, P. G. 1967 Self-propulsion of a deformable body in a perfect fluid. J. Fluid Mech. 28, 385389.Google Scholar
Spagnolie, S. E. & Shelley, M. J. 2009 Shapechanging bodies in fluid: hovering, ratcheting, and bursting. Phys. Fluids 21, 013103.Google Scholar
Wells, M. J. 1990 Oxygen extraction and jet propulsion in Cephalopods. Can. J. Zool. 68, 815824.Google Scholar
Weymouth, G. D., Dommermuth, D. G., Hendrickson, K. & Yue, D. K.-P. 2006 Advancements in Cartesian-grid methods for computational ship hydrodynamics. 26th Symposium on Naval Hydrodynamics, Rome, Italy, 17–22 September 2006.Google Scholar
Weymouth, G. D. & Triantafyllou, M. S. 2012 Global vorticity shedding for a shrinking cylinder. J. Fluid Mech. 702, 470487.Google Scholar
Weymouth, G. D. & Yue, D. K.-P. 2011 Boundary data immersion method for Cartesian-grid simulations of fluid-body interaction problems. J. Comput. Phys. 230, 16.CrossRefGoogle Scholar
Wibawa, M. S., Steele, S. C., Dahl, J. D., Rival, D. E., Weymouth, G. D. & Triantafyllou, M. S. 2012 Global vorticity shedding for a vanishing wing. J. Fluid Mech. 695, 112134.Google Scholar
Williamson, G. R. 1965 Underwater observations of the squid Illex illecebrosus Lesueur in Newfoundland waters. Can. Field Natur. 79, 239247.CrossRefGoogle Scholar