Numerical investigation on Rayleigh-Bénard-Marangoni flow of water near the maximum density in cylindrical pools with large aspect ratios
We report a set of direct numerical simulation results on Rayleigh-Bénard-Marangoni (R-B-M) flow of cold water in the cylindrical pools. The heat transfer between the free surface and the environment is considered. The aspect ratio Г of the cylindrical pool varies from 2 to 8. Rayleigh (Ra) and Biot...
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Published in | Journal of mechanical science and technology Vol. 36; no. 10; pp. 5291 - 5298 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
Seoul
Korean Society of Mechanical Engineers
01.10.2022
|
Subjects | |
Online Access | Get full text |
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Summary: | We report a set of direct numerical simulation results on Rayleigh-Bénard-Marangoni (R-B-M) flow of cold water in the cylindrical pools. The heat transfer between the free surface and the environment is considered. The aspect ratio
Г
of the cylindrical pool varies from 2 to 8. Rayleigh (Ra) and Biot (Bi) numbers are respectively confined in Ra ≤ 10
4
and 0 < Bi ≤ 50. The flow onset critical Ra is determined and the influences of Bi and the density inversion parameter (
Θ
m
) on the critical Ra are analyzed. The primary bifurcation flow structures of R-B-M flow are shown and the evolution of the flow structures with Ra and Bi at different Θ
m
is observed. Furthermore, the heat transfer ability is estimated by Nusselt number. The results indicate that the critical Ra of the flow onset increases with increasing Bi and
Θ
m
. But it decreases with the increase of
Г
. The primary bifurcation pattern is multicellular flow. With increasing
Г
, the number of flow cells in multicellular flow increases fast. With increasing Ra, the up-triangular and up-quadrilateral flow structures appear at
Г
= 4, and finally transits to the up one-torus. With increasing Ra and
Г
, and decreasing
Θ
m
, average Nusselt number increases monotonically. However, with increasing Bi, it first increases, and then decreases. |
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ISSN: | 1738-494X 1976-3824 |
DOI: | 10.1007/s12206-022-0941-9 |