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A trajectory equation for walking droplets: hydrodynamic pilot-wave theory

Published online by Cambridge University Press:  27 November 2013

Anand U. Oza
Affiliation:
Department of Mathematics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
Rodolfo R. Rosales
Affiliation:
Department of Mathematics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
John W. M. Bush*
Affiliation:
Department of Mathematics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
*
Email address for correspondence: bush@math.mit.edu

Abstract

We present the results of a theoretical investigation of droplets bouncing on a vertically vibrating fluid bath. An integro-differential equation describing the horizontal motion of the drop is developed by approximating the drop as a continuous moving source of standing waves. Our model indicates that, as the forcing acceleration is increased, the bouncing state destabilizes into steady horizontal motion along a straight line, a walking state, via a supercritical pitchfork bifurcation. Predictions for the dependence of the walking threshold and drop speed on the system parameters compare favourably with experimental data. By considering the stability of the walking state, we show that the drop is stable to perturbations in the direction of motion and neutrally stable to lateral perturbations. This result lends insight into the possibility of chaotic dynamics emerging when droplets walk in complex geometries.

Type
Papers
Copyright
©2013 Cambridge University Press 

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References

Benjamin, T. B. & Ursell, F. 1954 The stability of the plane free surface of a liquid in vertical periodic motion. Proc. R. Soc. A 225, 505515.Google Scholar
Bush, J. W. M. 2010 Quantum mechanics writ large. Proc. Natl Acad. Sci. USA 107 (41), 1745517456.Google Scholar
Couder, Y. & Fort, E. 2006 Single-particle diffraction and interference at a macroscopic scale. Phys. Rev. Lett. 97, 154101.CrossRefGoogle Scholar
Couder, Y., Gautier, C.-H. & Boudaoud, A. 2005 From bouncing to floating: noncoalescence of drops on a fluid bath. Phys. Rev. Lett. 94, 177801.Google Scholar
Crommie, M., Lutz, C. & Eigler, D. 1993 Confinement of electrons to quantum corrals on a metal surface. Science 262 (5131), 218220.CrossRefGoogle ScholarPubMed
Douady, S. 1990 Experimental study of the Faraday instability. J. Fluid Mech. 221, 383409.CrossRefGoogle Scholar
Eddi, A., Fort, E., Moisy, F. & Couder, Y. 2009 Unpredictable tunneling of a classical wave–particle association. Phys. Rev. Lett. 102, 240401.Google Scholar
Eddi, A., Moukhtar, J., Perrard, S., Fort, E. & Couder, Y. 2012 Level splitting at macroscopic scale. Phys. Rev. Lett. 108, 264503.Google Scholar
Eddi, A., Sultan, E., Moukhtar, J., Fort, E., Rossi, M. & Couder, Y. 2011 Information stored in Faraday waves: the origin of path memory. J. Fluid Mech. 675, 433463.Google Scholar
Eddi, A., Terwagne, D., Fort, E. & Couder, Y. 2008 Wave propelled ratchets and drifting rafts. Europhys. Lett. 82, 44001.Google Scholar
Faraday, M. 1831 On a peculiar class of acoustical figures, and on certain forms assumed by groups of particles upon vibrating elastic surfaces. Phil. Trans. R. Soc. Lond. 121, 299340.Google Scholar
Fort, E., Eddi, A., Boudaoud, A., Moukhtar, J. & Couder, Y. 2010 Path-memory induced quantization of classical orbits. Proc. Natl Acad. Sci. USA 107 (41), 1751517520.Google Scholar
Harris, D. M. & Bush, J. W. M. 2013 Droplets walking in a rotating frame: from quantized orbits to multinodal statistics. J. Fluid Mech. (submitted).Google Scholar
Harris, D. M., Moukhtar, J., Fort, E., Couder, Y. & Bush, J. W. M. 2013 Wavelike statistics from pilot-wave dynamics in a circular corral. Phys. Rev. E 88, 011001.CrossRefGoogle Scholar
Kumar, K. 1996 Linear theory of Faraday instability in viscous fluids. Proc. R. Soc. A 452, 11131126.Google Scholar
Miles, J. & Henderson, D. 1990 Parametrically forced surface waves. Annu. Rev. Fluid Mech. 22, 143165.Google Scholar
Moláček, J. & Bush, J. W. M. 2013a Drops bouncing on a vibrating bath. J. Fluid Mech. 727, 582611.Google Scholar
Moláček, J. & Bush, J. W. M. 2013b Drops walking on a vibrating bath: towards a hydrodynamic pilot-wave theory. J. Fluid Mech. 727, 612647.Google Scholar
Müller, H. W., Friedrich, R. & Papathanassiou, D. 1998 Theoretical and experimental investigations of the Faraday instability. In Evolution of Spontaneous Structures in Dissipative Continuous Systems (ed. Busse, F. & Müller, S. C.), Lecture Notes in Physics, vol. 55, pp. 231265. Springer.Google Scholar
Oza, A. U., Harris, D. M., Rosales, R. R. & Bush, J. W. M. 2013 Pilot-wave dynamics in a rotating frame: on the emergence of orbital quantization. J. Fluid Mech. (submitted).Google Scholar
Perrard, S., Labousse, M., Miskin, M., Fort, E. & Couder, Y. 2013 Macroscopic wave–particle eigenstates. Under review.Google Scholar
Prosperetti, A. 1976 Viscous effects on small-amplitude surface waves. Phys. Fluids 19 (2), 195203.Google Scholar
Protière, S., Boudaoud, A. & Couder, Y. 2006 Particle–wave association on a fluid interface. J. Fluid Mech. 554, 85108.Google Scholar
Shirokoff, D. 2013 Bouncing droplets on a billiard table. Chaos 23, 013115.CrossRefGoogle ScholarPubMed
Stuart, J. T. 1958 On the nonlinear mechanics of hydrodynamic stability. J. Fluid Mech. 4, 121.CrossRefGoogle Scholar
Walker, J. 1978 Drops of liquid can be made to float on the liquid. What enables them to do so? Sci. Am. 238-6, 151–158.Google Scholar
Wind-Willassen, Ø., Moláček, J., Harris, D. M. & Bush, J. W. M. 2013 Exotic states of bouncing and walking droplets. Phys. Fluids 25, 082002.Google Scholar