Author, as appears in the article.: Sánchez O; Ruiz X; Pujalte M; Mercader I; Batiste O; Gavaldà J
Department: Química Física i Inorgànica
URV's Author/s: Gavaldà Martínez, Josefa / Ruiz Martí, José Javier
Keywords: Space stations Shear cells Shear cell Numerical simulation Microgravity conditions Melted semiconductors Mass diffusion coefficients Manned space flight Long capillaries Liquids Liquid metals International space stations Inter-diffusion coefficients Heat convection Extra vehicular activities Diffusion in solids Diffusion coefficients Diffusion Computer simulation Capillarity Buoyancy-driven convection Buoyancy Binary alloys
Abstract: Abstract The accurate determination of mass diffusion coefficients is a technologically relevant problem that has implications on the modelling and control of material processes such as crystal growth and casting. It is also important in the validation of different theories of atomic diffusion. The experimental determination of these coefficients, when there is a liquid phase, is difficult due to the unavoidable presence of buoyancy driven convection currents that enhance mass transport and disturb diffusion measurements. To minimize as much as possible these problems, long capillaries are used in order to confine the fluid and reduce the intensity of the convective motions. These measurements have also been done in reduced gravity environments, but the residual gravity may still be able to induce buoyancy driven convection motions. The aim of our work is to analyze the impact of low solutal Rayleigh number environments on the accuracy of the interdiffusion coefficient measurements using long capillaries. In the present study we deal with two liquid systems; photovoltaic silicon and Al-based liquid binary alloys at high temperature. We have numerically simulated two different experimental techniques used to determine the diffusion coefficients; the shear cell and the long capillary techniques. We also consider the effect of rotating the cylindrical cell along their axis as a mechanism to reduce axial convective transport even in Earth laboratories. Finally, we use typical accelerometric signals from the International Space Station (ISS) in the quasi-steady range of frequencies. The signals concentrate on typical station reboosts because the accelerometric level of the rest of potentially dangerous disturbances - dockings, undockings and Extra Vehicular Activities, EVAs - is considerably lower. © 2015 Elsevier Ltd. All rights reserved.
Thematic Areas: Thermodynamics Mechanics Mechanical engineering Materiais Matemática / probabilidade e estatística Interdisciplinar Geociências Fluid flow and transfer processes Engineering, mechanical Engenharias iv Engenharias iii Engenharias ii Engenharias i Condensed matter physics Ciências biológicas i Ciências ambientais Ciências agrárias i Ciência de alimentos Biotecnología Astronomia / física
licence for use: https://creativecommons.org/licenses/by/3.0/es/
Author's mail: fina.gavalda@urv.cat josepxavier.ruiz@urv.cat
Author identifier: 0000-0001-7881-4192 0000-0003-4020-4457
Record's date: 2024-09-07
Papper version: info:eu-repo/semantics/acceptedVersion
Link to the original source: https://www.sciencedirect.com/science/article/abs/pii/S0017931015002240
Licence document URL: https://repositori.urv.cat/ca/proteccio-de-dades/
Papper original source: International Journal Of Heat And Mass Transfer. 86 508-518
APA: Sánchez O; Ruiz X; Pujalte M; Mercader I; Batiste O; Gavaldà J (2015). On the determination of diffusion coefficients in two-component alloys and doped semiconductors. Several implications concerning the International Space Station. International Journal Of Heat And Mass Transfer, 86(), 508-518. DOI: 10.1016/j.ijheatmasstransfer.2015.02.061
Article's DOI: 10.1016/j.ijheatmasstransfer.2015.02.061
Entity: Universitat Rovira i Virgili
Journal publication year: 2015
Publication Type: Journal Publications
Repositori URV