Temporal chaos in Boussinesq magnetoconvection
Abstract
Twodimensional Boussinesq magnetoconvection with idealized stressfree boundary conditions is numerically investigated in order to make clear the difference between chaos and turbulence. It is shown that the longterm behavior of magnetoconvection exhibits spatially coherent and temporally chaotic rolls in marked contrast to highly turbulent fluids. It is also shown that heat transport becomes larger anomalously when the polarity reversal of the magnetic field occurs intermittently in the case of temporally chaotic magnetoconvection. It is found that the Poincare return map of the relative maximum temperature fluctuation of partial differential equations as a function of the preceding maximum resembles the famous Lorenz plot in narrow rolls of magnetoconvection. The chaotic behavior of narrow rolls for individual parameter values robustly persists up to rolls about one fifth as wide as they are high near the codimensiontwo bifurcation point.
 Authors:
 College of Engineering, Nihon University, Koriyama, Fukushima 9638642 (Japan)
 (Japan)
 Publication Date:
 OSTI Identifier:
 20960094
 Resource Type:
 Journal Article
 Resource Relation:
 Journal Name: Physics of Plasmas; Journal Volume: 14; Journal Issue: 1; Other Information: DOI: 10.1063/1.2430517; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; BIFURCATION; BOUNDARY CONDITIONS; CONVECTION; ELECTRON TEMPERATURE; FLUCTUATIONS; FLUIDS; ION TEMPERATURE; MAGNETIC FIELDS; MAGNETOHYDRODYNAMICS; PARTIAL DIFFERENTIAL EQUATIONS; PLASMA; PLASMA SIMULATION; STRESSES; TURBULENCE; TWODIMENSIONAL CALCULATIONS
Citation Formats
Bekki, Naoaki, Moriguchi, Hirofumi, and Fundamental Science, Gifu National College of Technology, Motosu, Gifu 5010495. Temporal chaos in Boussinesq magnetoconvection. United States: N. p., 2007.
Web. doi:10.1063/1.2430517.
Bekki, Naoaki, Moriguchi, Hirofumi, & Fundamental Science, Gifu National College of Technology, Motosu, Gifu 5010495. Temporal chaos in Boussinesq magnetoconvection. United States. doi:10.1063/1.2430517.
Bekki, Naoaki, Moriguchi, Hirofumi, and Fundamental Science, Gifu National College of Technology, Motosu, Gifu 5010495. Mon .
"Temporal chaos in Boussinesq magnetoconvection". United States.
doi:10.1063/1.2430517.
@article{osti_20960094,
title = {Temporal chaos in Boussinesq magnetoconvection},
author = {Bekki, Naoaki and Moriguchi, Hirofumi and Fundamental Science, Gifu National College of Technology, Motosu, Gifu 5010495},
abstractNote = {Twodimensional Boussinesq magnetoconvection with idealized stressfree boundary conditions is numerically investigated in order to make clear the difference between chaos and turbulence. It is shown that the longterm behavior of magnetoconvection exhibits spatially coherent and temporally chaotic rolls in marked contrast to highly turbulent fluids. It is also shown that heat transport becomes larger anomalously when the polarity reversal of the magnetic field occurs intermittently in the case of temporally chaotic magnetoconvection. It is found that the Poincare return map of the relative maximum temperature fluctuation of partial differential equations as a function of the preceding maximum resembles the famous Lorenz plot in narrow rolls of magnetoconvection. The chaotic behavior of narrow rolls for individual parameter values robustly persists up to rolls about one fifth as wide as they are high near the codimensiontwo bifurcation point.},
doi = {10.1063/1.2430517},
journal = {Physics of Plasmas},
number = 1,
volume = 14,
place = {United States},
year = {Mon Jan 15 00:00:00 EST 2007},
month = {Mon Jan 15 00:00:00 EST 2007}
}

We present numerical simulations of coupled GinzburgLandau equations describing parametrically excited waves which reveal persistent dynamics due to the occurrence of phase slips in sequential pairs, with the second phase slip quickly following and negating the first. Of particular interest are solutions where these double phase slips occur irregularly in space and time within a spatially localized region. An effective phase diffusion equation utilizing the longterm phase conservation of the solution explains the localization of this new form of amplitude chaos. {copyright} {ital 1996 The American Physical Society.}

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Comment on {open_quote}{open_quote}Bifurcations from periodic solution in a simplified model of twodimensional magnetoconvection,{close_quote}{close_quote} by N. Bekki and T. Karakisawa [Phys. Plasmas {bold 2}, 2945 (1995)]
In a recent paper, N. Bekki and T. Karakisawa (Ref. 1) considered twodimensional Boussinesq convection in an imposed vertical magnetic field. We would like to point out that a number of their results and claims are incorrect. These can be seen by comparing their work with ours. (AIP). {copyright}{ital 1996 American Institute of Physics}