Europhys. Lett.
Volume 48, Number 6, December 1999
Page(s) 629 - 633
Section Electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics
Published online 01 September 2002
DOI: 10.1209/epl/i1999-00530-3

Europhys. Lett, 48 (6), pp. 629-633 (1999)

Experimental evidence of chaotic advection in a convective flow

G. Boffetta 1,2, M. Cencini 3,4, S. Espa 5 and G. Querzoli 6

1 Dipartimento di Fisica Generale, Università di Torino
Via P. Giuria 1, 10125 Torino, Italy
2 Istituto Nazionale di Fisica della Materia, Unità di Torino Università - Torino, Italy
3 Dipartimento di Fisica, Università "La Sapienza''- P.le Aldo Moro 2,00185Roma,Italy
4 Istituto Nazionale di Fisica della Materia - Unità di Roma I, Roma, Italy
5 Dipartimento di Idraulica Trasporti e Strade, Università "La Sapienza''
Via Eudossiana 18, 00185 Roma, Italy
6 Dipartimento di Ingegneria del Territorio, Università di Cagliari
P.zza d'Armi, 90123, Cagliari, Italy

(received 4 August 1999; accepted in final form 20 October 1999)

PACS. 47.27Te - Convection and heat transfer.
PACS. 05.45Tp - Time series analysis.
PACS. 05.45Ac - Low-dimensional chaos.


Lagrangian chaos is experimentally investigated in a convective flow by means of Particle Tracking Velocimetry. The Finite Size Lyapunov Exponent analysis is applied to quantify dispersion properties at different scales. In the range of parameters of the experiment, Lagrangian motion is found to be chaotic. Moreover, the Lyapunov exponent depends on the Rayleigh number as ${\cal R}a^{1/2}$. A simple dimensional argument for explaining the observed power law scaling is proposed.


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