Mathematical modeling of solidification process near the inner core boundary of the Earth / Alexandrov D.V., Malygin A.P. // Applied Mathematical Modelling. - 2013. - V. 37, l. 22. - P. 9368-9378.

ISSN:
0307904X
Type:
Article
Abstract:
Radially symmetric analytic solutions of the heat and mass transfer equations governing convection in the Earth's fluid core are found in terms of deviations from the adiabatic reference state. We demonstrate that an increase of the convective velocity leads to a decrease of the light constituent mass fraction and specific entropy. Where fluid is rising/descending, convective motions decrease/increase the mass fraction and entropy at the inner core boundary (ICB). The influence of convective motions on the thermal fluxes at the core mantle boundary is studied. On the basis of exact solutions we demonstrate that the liquid is supercooled near the ICB. An important point is that an increase in the convective velocity directed to the ICB increases the constitutional supercooling. We show that the anelastic model (AM) can be used only at small supercoolings near the ICB. The most probable solidification scenario "constitutional supercooling and morphological instability" should be described by a mushy layer theory near the ICB and by the AM in the rest region of the fluid outer core. On the basis of dendritic theory and selection mechanisms of crystal growth the dendrite tip radius and interdendritic spacing in the mushy layer at the ICB are determined in the presence of convection. © 2013 Elsevier Inc.
Author keywords:
Dendrites; Inner core boundary; Mathematical modeling; Mushy layer; Solidification
Index keywords:
Constitutional supercooling; Convective velocity; Core-mantle boundary; Heat and mass transfer; Inner core boundary; Morphological instability; Mushy layer; Solidification process; Dendrites (metallog
DOI:
10.1016/j.apm.2013.04.032
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Affiliations Department of Mathematical Physics, Ural Federal University, Ekaterinburg 620000, Russian Federation
Author Keywords Dendrites; Inner core boundary; Mathematical modeling; Mushy layer; Solidification
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Correspondence Address Alexandrov, D.V.; Department of Mathematical Physics, Ural Federal University, Ekaterinburg 620000, Russian Federation; email: Dmitri.Alexandrov@usu.ru
CODEN AMMOD
Language of Original Document English
Abbreviated Source Title Appl. Math. Model.
Source Scopus