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Experimental investigation of the Marangoni effect on the stability of a double-diffusive layerStability experiments were carried out in 4-cm-thick, salt-stratified fluid layer by heating from below and cooling from above. The bottom boundary was rigid while the top was either free or rigid. The initial solute Rayleigh number varied from 2.5 x 10(exp 6) to 4.6 x 10(exp 7). For the rigid-free case, at initial solute Rayleigh numbers R(sub s) greater than 5.4 x 10(exp 6), thermal Marangoni instabilities were observed to onset along the free surface at a relatively low thermal Rayleigh number, R(sub t). The convection was very weak, and it had almost no effect on the concentration and temperature distributions. Double-diffusive instabilities along the top free surface were observed to onset at a higher R(sub t), with much stronger convection causing changes in the concentration and temperature distributions near the top. At a yet higher R(sub t), double-diffusive convection was observed to onset along the bottom boundary. Fluid motion in the layer then evolved into fully developed thermal convection of a homogeneous fluid without any further increase in the imposed Delta T. For layers with R(sub s) less than 5.4 x 10(exp 6), Marangoni and double-diffusive instabilities onset simultaneously along the free surface first, while double-diffusive instabilities along the bottom wall onset at a higher R(sub t).
Document ID
19950008114
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Tanny, Josef
(Arizona Univ. Phoenix, AZ, United States)
Chen, Chuan F.
(Arizona Univ. Phoenix, AZ, United States)
Date Acquired
September 6, 2013
Publication Date
August 1, 1994
Publication Information
Publication: NASA. Lewis Research Center, Second Microgravity Fluid Physics Conference
Subject Category
Fluid Mechanics And Heat Transfer
Accession Number
95N14528
Funding Number(s)
CONTRACT_GRANT: NAG3-1386
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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