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Modestov, Mikhail
Publications (3 of 3) Show all publications
Modestov, M., Kolemen, E., Fisher, A. E. & Hvasta, M. G. (2018). Electromagnetic control of heat transport within a rectangular channel filled with flowing liquid metal. Nuclear Fusion, 58(1), Article ID 016009.
Open this publication in new window or tab >>Electromagnetic control of heat transport within a rectangular channel filled with flowing liquid metal
2018 (English)In: Nuclear Fusion, ISSN 0029-5515, E-ISSN 1741-4326, Vol. 58, no 1, article id 016009Article in journal (Refereed) Published
Abstract [en]

The behavior of free-surface, liquid-metal flows exposed to both magnetic fields and an injected electric current is investigated via experiment and numerical simulations. The purpose of this paper is to provide an experimental and theoretical proof-of-concept for enhanced thermal mixing within fast-flowing, free-surface, liquid-metal plasma facing components that could be used in next-generation fusion reactors. The enhanced hydrodynamic and thermal mixing induced by non-uniform current density near the electrodes appears to improve heat transfer through the thickness of the flowing metal. Also, the outflow heat flux profile is strongly affected by the impact of the J x B forces on flow velocity. The experimental results are compared to COMSOL simulations in order to lay the groundwork for future liquid-metal research.

Place, publisher, year, edition, pages
IOP PUBLISHING LTD, 2018
Keywords
liquid metal experiment, heat transport, MHD simulations
National Category
Physical Sciences
Identifiers
urn:nbn:se:kth:diva-217718 (URN)10.1088/1741-4326/aa8bf4 (DOI)000414591400003 ()2-s2.0-85038628750 (Scopus ID)
Note

QC 20171123

Available from: 2017-11-23 Created: 2017-11-23 Last updated: 2017-11-23Bibliographically approved
Jukimenko, O., Modestov, M., Dion, C. M., Marklund, M. & Bychkov, V. (2017). Multilevel model for magnetic deflagration in nanomagnet crystals. Physical Review B, 95(17), Article ID 174403.
Open this publication in new window or tab >>Multilevel model for magnetic deflagration in nanomagnet crystals
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2017 (English)In: Physical Review B, ISSN 2469-9950, E-ISSN 2469-9969, Vol. 95, no 17, article id 174403Article in journal (Refereed) Published
Abstract [en]

We extend the existing theoretical model for determining the characteristic features of magnetic deflagration in nanomagnet crystals. For the first time, all energy levels are accounted for calculation of the the Zeeman energy, the deflagration velocity, and other parameters. It reduces the final temperature and significantly changes the propagation velocity of the spin-flipping front. We also consider the effect of a strong transverse magnetic field, and show that the latter significantly modifies the spin-state structure, leading to an uncertainty concerning the activation energy of the spin flipping. Our front velocity prediction for a crystal of Mn-12 acetate in a longitudinal magnetic field is in much better agreement with experimental data than the previous reduced-model results.

Place, publisher, year, edition, pages
American Physical Society, 2017
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:kth:diva-207889 (URN)10.1103/PhysRevB.95.174403 (DOI)000400659900001 ()2-s2.0-85024405315 (Scopus ID)
Note

QC 20170530

Available from: 2017-05-30 Created: 2017-05-30 Last updated: 2018-09-19Bibliographically approved
Xing, G., Zhao, Y., Modestov, M., Zhou, C., Gao, Y. & Law, C. K. (2017). Thermal-diffusional instability in white dwarf flames: Regimes of flame pulsation. In: 10th U.S. National Combustion Meeting: . Paper presented at 10th U.S. National Combustion Meeting, 23 April 2017 through 26 April 2017. Eastern States Section of the Combustion Institute
Open this publication in new window or tab >>Thermal-diffusional instability in white dwarf flames: Regimes of flame pulsation
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2017 (English)In: 10th U.S. National Combustion Meeting, Eastern States Section of the Combustion Institute , 2017Conference paper, Published paper (Refereed)
Abstract [en]

Thermal-diffusional pulsation behaviors in planar as well as outwardly and inwardly propagating white dwarf carbon flames are systematically studied. It is shown that different equations of state in non-degenerate and degenerate matters in white dwarfs lead to different criterions of flame pulsation, with the critical Zel'dovich number in the later twice as large as in the former. For realistic physical conditions in white dwarf carbon flames, the asymptotic degenerate equation of state is adopted and the simplified one-step reaction rate for nuclear reactions are used to study the flame propagation. Flame front pulsation behaviors in different environmental densities and temperatures are obtained to form the regime diagram of pulsation, showing that carbon flames pulsate in the typical density and temperature. While being stable at higher temperatures, in relatively lower temperatures the amplitude of the flame pulsation becomes larger. In outwardly propagating spherical flames the pulsation instability is enhanced and flames are also easier to quench, while the inwardly propagating flames are more stable. 

Place, publisher, year, edition, pages
Eastern States Section of the Combustion Institute, 2017
Keywords
Flame instability, Supernova explosion, White dwarf, Carbon, Equations of state, Flammability testing, Nuclear reactions, Supernovae, White dwarfs, Degenerate equation, Diffusional instabilities, Environmental density, Lower temperatures, Physical conditions, Propagating spherical flames, Combustion
National Category
Astronomy, Astrophysics and Cosmology
Identifiers
urn:nbn:se:kth:diva-236872 (URN)2-s2.0-85048946297 (Scopus ID)
Conference
10th U.S. National Combustion Meeting, 23 April 2017 through 26 April 2017
Note

QC 20181214

Available from: 2018-12-14 Created: 2018-12-14 Last updated: 2018-12-14Bibliographically approved
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