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Instabilities of convection rolls in a fluid of moderate Prandtl number

Published online by Cambridge University Press:  19 April 2006

F. H. Busse  and
R. M. Clever
F. H. Busse
Affiliation:
Institute of Geophysics and Planetary Physics, University of California, Los Angeles
R. M. Clever
Affiliation:
Institute of Geophysics and Planetary Physics, University of California, Los Angeles
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Abstract

The instabilities of two-dimensional convection rolls in a horizontal fluid layer heated from below are investigated in the case when the Prandtl number is seven or lower. Two new mechanisms of instability are described theoretically as well as experimentally. The knot instability causes the transition to spoke-pattern convection at higher Rayleigh numbers while the skewed varicose instability accomplishes a change to larger horizontal wavelengths of the convection rolls. Both instabilities disappear in the limits of small and large Prandtl number. Although the experimental methods fail in realizing closely the infinitely conducting boundaries assumed in the theory, the observations agree in all qualitative aspects with the theoretical predictions.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 91 , Issue 2 , 23 March 1979 , pp. 319 - 335
Copyright
© 1979 Cambridge University Press

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References

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