Visualization of Double-Diffusive Convection and Unsteady Solidification on a Vertical Circular Cylinder


This paper describes experimental results on the solidification process over the vertically positioned circular cylinder, placed in an aqueous solution of sodium nitrate, where the aqueous solution in the vessel is heated from the bottom. After the initiation of solidification by cooling the cylinder below the liquidus temperature, the pure ice formation on the cylinder causes the rejection of solute into the surrounding aqueous solution. The solute enriched vertical fluid layer over the ice then falls on the bottom of the vessel due to its higher density, and accumulates there. This process results in the formation of solute rich and hot horizontal layer (heavy layer), underlying the relatively cold but less concentrated fluid layer (light layer). As this process advances, however, because of the continuing influx of solute rich fluid, the lower heavy layer occupies more space, and the interface of the two layers rises slowly. The pH indicator method has been successfully employed in order to visualize the flows during this process. In this report, we document the evolution of both temperature and flow fields in the aqueous solution quantitatively, as the solidification progresses and the density discontinuity of the two layers rises.

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Ohnishi, K. , Kimura, S. , Kiwata, T. , Komatsu, N. and Kono, T. (2015) Visualization of Double-Diffusive Convection and Unsteady Solidification on a Vertical Circular Cylinder. Journal of Flow Control, Measurement & Visualization, 3, 154-160. doi: 10.4236/jfcmv.2015.34015.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] Yasukawa, K., Noda, T., Muraoka, H., Adachi, M., Matsunaga, I. and Ehara, S. (2010) Long-Term Prospects of Geothermal Energy Uses and Their Environmental Effects in Japan. Proceedings of World Geothermal Congress 2010 (CD-ROM), Bali, Indonesia, 25-29 April 2010, 4 p.
[2] Hardee, H.C. (1981) Convective Heat Extraction from Molten Magma. Journal of Volcanology and Geothermal Research, 10, 175-193.
[3] Morita, K. and Tago, M. (2000) Operational Characteristics of the GAIA Snow-Melting System in Ninohe, Japan. Geo-Heat Center, 21, 5-11.
[4] Huppert, H.E. and Turner, J.S. (1981) A Laboratory Model of a Replenished Magma Chamber. Earth and Planetary Science Letters, 54, 144-152.
[5] Huppert, H.E. and Sparks, R.S.J. (1984) Double-Diffusive Convection Due to Crystallization in Magmas. Annual Review of Earth and Planetary Sciences, 12, 11-37.
[6] Worster, M.G. (1986) Solidification of an Alloy from a Cooled Boundary. Journal of Fluid Mechanics, 167, 481-501.
[7] Huppert, H.E. (1990) The Fluid Mechanics of Solidification. Journal of Fluid Mechanics, 212, 209-240.
[8] Wettlaufer, J.S., Worster, M.G. and Huppert, H.E. (1997) Natural Convection during Solidification of an Alloy from Above with Application to the Evolution of Sea Ice. Journal of Fluid Mechanics, 344, 291-316.
[9] Baker, D.J. (1966) A Technique for Precise Measurement of Small Fluid Velocities. Journal of Fluid Mechanics, 26, 573-575.

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