Hostname: page-component-cd9895bd7-mkpzs Total loading time: 0 Render date: 2024-12-23T09:56:49.707Z Has data issue: false hasContentIssue false

Swimming sheet in a density-stratified fluid

Published online by Cambridge University Press:  04 July 2019

Rajat Dandekar
Affiliation:
School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907, USA
Vaseem A. Shaik
Affiliation:
School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907, USA
Arezoo M. Ardekani*
Affiliation:
School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907, USA
*
Email address for correspondence: [email protected]

Abstract

In this work, we theoretically investigate the swimming velocity of a Taylor swimming sheet immersed in a linearly density-stratified fluid. We use a regular perturbation expansion approach to estimate the swimming velocity up to second order in wave amplitude. We divide our analysis into two regimes of low ($\ll O(1)$) and finite Reynolds numbers. We use our solution to understand the effect of stratification on the swimming behaviour of organisms. We find that stratification significantly influences motility characteristics of the swimmer such as the swimming speed, hydrodynamic power expenditure, swimming efficiency and the induced mixing, quantified by mixing efficiency and diapycnal eddy diffusivity. We explore this dependence in detail for both low and finite Reynolds number and elucidate the fundamental insights obtained. We expect our work to shed some light on the importance of stratification in the locomotion of organisms living in density-stratified aquatic environments.

Type
JFM Papers
Copyright
© 2019 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

Ardekani, A. M., Doostmohammadi, A. & Desai, N. 2017 Transport of particles, drops, and small organisms in density stratified fluids. Phys. Rev. Fluids 2 (10), 100503.Google Scholar
Ardekani, A. M. & Stocker, R. 2010 Stratlets: low Reynolds number point-force solutions in a stratified fluid. Phys. Rev. Lett. 105 (8), 084502.Google Scholar
Arrigo, K. R., Robinson, D. H., Worthen, D. L., Dunbar, R. B., DiTullio, G. R., VanWoert, M. & Lizotte, M. P. 1999 Phytoplankton community structure and the drawdown of nutrients and CO2 in the Southern Ocean. Science 283 (5400), 365367.Google Scholar
Blake, J. R. 1971 A spherical envelope approach to ciliary propulsion. J. Fluid Mech. 46 (1), 199208.Google Scholar
Brennen, C. & Winet, H. 1977 Fluid mechanics of propulsion by cilia and flagella. Annu. Rev. Fluid Mech. 9 (1), 339398.Google Scholar
Campbell, R. W. & Dower, J. F. 2003 Role of lipids in the maintenance of neutral buoyancy by zooplankton. Mar. Ecol. Prog. Ser. 263, 9399.Google Scholar
Candelier, F., Mehaddi, R. & Vauquelin, O. 2014 The history force on a small particle in a linearly stratified fluid. J. Fluid Mech. 749, 184200.Google Scholar
Chaudhury, T. K. 1979 On swimming in a visco-elastic liquid. J. Fluid Mech. 95 (1), 189197.Google Scholar
Dewar, W. K., Bingham, R. J., Iverson, R. L., Nowacek, D. P., St Laurent, L. C. & Wiebe, P. H. 2006 Does the marine biosphere mix the ocean? J. Mar. Res. 64 (4), 541561.Google Scholar
Doostmohammadi, A., Dabiri, S. & Ardekani, A. M. 2014 A numerical study of the dynamics of a particle settling at moderate Reynolds numbers in a linearly stratified fluid. J. Fluid Mech. 750, 532.Google Scholar
Doostmohammadi, A., Stocker, R. & Ardekani, A. M. 2012 Low-Reynolds-number swimming at pycnoclines. Proc. Natl Acad. Sci. USA 109 (10), 38563861.Google Scholar
Du, J., Keener, J. P., Guy, R. D. & Fogelson, A. L. 2012 Low-Reynolds-number swimming in viscous two-phase fluids. Phys. Rev. E 85 (3), 036304.Google Scholar
Eastman, J. T. 1985 The evolution of neutrally buoyant notothenioid fishes: their specializations and potential interactions in the antarctic marine food web. In Antarctic Nutrient Cycles and Food Webs, pp. 430436. Springer.Google Scholar
Elfring, G. J. & Goyal, G. 2016 The effect of gait on swimming in viscoelastic fluids. J. Non-Newtonian Fluid Mech. 234, 814.Google Scholar
Elfring, G. J. & Lauga, E. 2009 Hydrodynamic phase locking of swimming microorganisms. Phys. Rev. Lett. 103 (8), 088101.Google Scholar
Elgeti, J., Winkler, R. G. & Gompper, G. 2015 Physics of microswimmers – single particle motion and collective behavior: a review. Rep. Prog. Phys. 78 (5), 056601.Google Scholar
Fu, H. C., Shenoy, V. B. & Powers, T. R. 2010 Low-Reynolds-number swimming in gels. Eur. Phys. Lett. 91 (2), 24002.Google Scholar
Harder, W. 1968 Reactions of plankton organisms to water stratification. Limnol. Oceanogr. 13 (1), 156168.Google Scholar
Heaney, S. I. & Eppley, R. W. 1981 Light, temperature and nitrogen as interacting factor affecting diel vertical migration of dinoflagellates in culture. J. Plankton Res. 3 (2), 331344.Google Scholar
Heuch, P. A. 1995 Experimental evidence for aggregation of salmon louse copepodids (Lepeophtheirus salmonis) in step salinity gradients. J. Mar. Biol. Assoc. UK 75 (4), 927939.Google Scholar
Katija, K. 2012 Biogenic inputs to ocean mixing. J. Expl Biol. 215 (6), 10401049.Google Scholar
Katija, K. & Dabiri, J. O. 2009 A viscosity-enhanced mechanism for biogenic ocean mixing. Nature 460 (7255), 624626.Google Scholar
Katz, D. F. 1974 On the propulsion of micro-organisms near solid boundaries. J. Fluid Mech. 64 (1), 3349.Google Scholar
Krieger, M. S., Dias, M. A. & Powers, T. R. 2015 Minimal model for transient swimming in a liquid crystal. Eur. Phys. J. E 38 (8), 19.Google Scholar
Lauga, E. 2007 Propulsion in a viscoelastic fluid. Phys. Fluids 19 (8), 083104.Google Scholar
Lauga, E. 2016 Bacterial hydrodynamics. Annu. Rev. Fluid Mech. 48 (1), 105130.Google Scholar
Lauga, E. & Powers, T. R. 2009 The hydrodynamics of swimming microorganisms. Rep. Prog. Phys. 72 (9), 096601.Google Scholar
Leshansky, A. M. 2009 Enhanced low-Reynolds-number propulsion in heterogeneous viscous environments. Phys. Rev. E 80 (5), 051911.Google Scholar
Lighthill, M. J. 1952 On the squirming motion of nearly spherical deformable bodies through liquids at very small Reynolds numbers. Commun. Pure Appl. Maths 5 (2), 109118.Google Scholar
Mahadevan, A., Dasaro, E., Lee, C. & Perry, M. J. 2012 Eddy-driven stratification initiates North Atlantic spring phytoplankton blooms. Science 337 (54), 5459.Google Scholar
Osborn, T. R. 1980 Estimates of the local rate of vertical diffusion from dissipation measurements. J. Phys. Oceanogr. 10 (1), 8389.Google Scholar
Phleger, C. F. 1998 Buoyancy in marine fishes: direct and indirect role of lipids. Am. Zool. 38 (2), 321330.Google Scholar
Reynolds, A. J. 1965 The swimming of minute organisms. J. Fluid Mech. 23 (2), 241260.Google Scholar
Sherman, B. S., Webster, I. T., Jones, G. J. & Oliver, R. L. 1998 Transitions between Aulacoseira and Anabaena dominance in a turbid river weir pool. Limnol. Oceanogr. 43 (8), 19021915.Google Scholar
Simoncelli, S., Thackeray, S. J. & Wain, D. J. 2017 Can small zooplankton mix lakes? Limnol. Oceanogr. 2 (5), 167176.Google Scholar
Strickler, J. R. 1975 Swimming of planktonic cyclops species (copepoda, crustacea): pattern, movements and their control. In Swimming and Flying in Nature, pp. 599613. Springer.Google Scholar
Sznitman, J., Purohit, P. K., Krajacic, P., Lamitina, T. & Arratia, P. E. 2010 Material properties of Caenorhabditis elegans swimming at low Reynolds number. Biophys. J. 98 (4), 617626.Google Scholar
Taylor, G. 1951 Analysis of the swimming of microscopic organisms. Proc. R. Soc. Lond. A 209 (1099), 447461.Google Scholar
Thorpe, S. A. 2005 The Turbulent Ocean. Cambridge University Press.Google Scholar
Tuck, E. O. 1968 A note on a swimming problem. J. Fluid Mech. 31 (02), 305308.Google Scholar
Visser, A. W. 2007 Biomixing of the oceans? Science 316 (5826), 838839.Google Scholar
Visser, A. W. & Jónasdóttir, S. H. 1999 Lipids, buoyancy and the seasonal vertical migration of Calanus finmarchicus . Oceanography 8, 100106.Google Scholar
Wagner, G. L., Young, W. R. & Lauga, E. 2014 Mixing by microorganisms in stratified fluids. J. Mar. Res. 72 (2), 4772.Google Scholar
Wang, S. & Ardekani, A. M. 2015 Biogenic mixing induced by intermediate Reynolds number swimming in stratified fluids. Sci. Rep. 5, 17448.Google Scholar
Yen, J., Brown, J. & Webster, D. R. 2003 Analysis of the flow field of the krill, Euphausia pacifica . Mar. Freshw. Behav. Physiol. 36 (4), 307319.Google Scholar
Yick, K. Y., Torres, C. R., Peacock, T. & Stocker, R. 2009 Enhanced drag of a sphere settling in a stratified fluid at small Reynolds numbers. J. Fluid Mech. 632, 4968.Google Scholar