Vortical flow patterns by the cooperative effect of convective and conductive heat transfers in particle-dispersed natural convection

Gu, Jingchen; Takeuchi, Shintaro; Fukada, Toshiaki; Kajishima, Takeo

doi:https://doi.org/10.1016/j.ijheatmasstransfer.2018.10.138

Vortical flow patterns by the cooperative effect of convective and conductive heat transfers in particle-dispersed natural convection

Gu, Jingchen; Takeuchi, Shintaro; Fukada, Toshiaki et al.

International Journal of Heat and Mass Transfer, 2019, 130, 946-959

アクセス数:813件（2025-08-16 10:09 集計）

固定URL: https://hdl.handle.net/11094/79017

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タイトル	Vortical flow patterns by the cooperative effect of convective and conductive heat transfers in particle-dispersed natural convection
著者	著者名 Gu, Jingchen
	NRID 1000050372628 1000050372628 ORCID 0000-0003-0091-4542 0000-0003-0091-4542 researchmap permalink 50372628 50372628 Scopus Author ID 35474283000 35474283000 著者名 Takeuchi, Shintaro
	NRID 1000030812127 1000030812127 著者名 Fukada, Toshiaki
	NRID 1000030185772 1000030185772 著者名 Kajishima, Takeo
キーワード等	Dense particle-laden flow
	Vortical structure
	Inhomogeneous media
	Heat transfer
	Conduction
	Convection
抄録	Cooperative effect of the conductive and convective heat fluxes on the development of vortical structures is studied in a particle-dispersed natural convection. A numerical approach is proposed that visualizes the heat transfer paths through the fluid and finite-volume particles (i.e., non-point particles) to show the spatial extension of the heat fluxes and its influence on the flow field. The approach is applied to a weakly-convective dense particulate system under the Rayleigh number containing more than 4000 particles (solid volume fraction 42.8%) of various conductivities. With highly-conductive particles (in comparison to the ambient fluid), local downward convection of a large-scale vortical flow strengthens the conductive heat flux near the bottom hot wall in the counter-convective direction by the increase of the vertical temperature gradient, and the observation of the spatial extension of the heat flux lines indicates that the increase of the solid volume fraction near the hot wall further strengthens the conductive heat flux. The paired upward convection causes strengthened conductive heat flux near the top cold wall by the same increase mechanism. The above interplay of the local heat fluxes in the dense solid-dispersed media are found to influence on the formation and transition of the large-scale vortical structures through the distribution of the moment of buoyancy in a horizontal plane. An analytical model for a low-dimensional vortex system shows that buoyancy gradient and vorticity diffusion could determine the time-development of the large-scale vortical structure.
出版者	Elsevier
収録物名	International Journal of Heat and Mass Transfer
巻(号)	130
ページ	946-959
刊行年月	2019-03
言語	英語
ハンドルURL	https://hdl.handle.net/11094/79017
PISSN	00179310
NCID	AA00680396
関連情報 (isVersionOf)	DOI (出版社版) https://doi.org/10.1016/j.ijheatmasstransfer.2018.10.138
アクセス権	open access
権利情報	© 2018 Elsevier Ltd. This manuscript version is made available under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International license.
出版タイプ	Accepted Manuscript
カテゴリ	学術雑誌論文 Journal Article

資源タイプ	学術雑誌論文
ローカル資源タイプ	学術雑誌論文
DCMI資源タイプ	text
DCTERMS.bibliographicCitation	International Journal of Heat and Mass Transfer. 2019, 130, p. 946-959
DC.title	Vortical flow patterns by the cooperative effect of convective and conductive heat transfers in particle-dispersed natural convection
DC.creator	Gu, Jingchen
	Takeuchi, Shintaro
	Fukada, Toshiaki
	Kajishima, Takeo
DC.publisher	Elsevier
DC.language' scheme='DCTERMS.RFC1766	英語
DC.type' scheme='DCTERMS.DCMIType	text
DCTERMS.issued' scheme='DCTERMS.W3CDTF	2019-03
DC.identifier	https://doi.org/10.1016/j.ijheatmasstransfer.2018.10.138
DC.subject	Dense particle-laden flow
	Vortical structure
	Inhomogeneous media
	Heat transfer
	Conduction
	Convection
DCTERMS.abstract	Cooperative effect of the conductive and convective heat fluxes on the development of vortical structures is studied in a particle-dispersed natural convection. A numerical approach is proposed that visualizes the heat transfer paths through the fluid and finite-volume particles (i.e., non-point particles) to show the spatial extension of the heat fluxes and its influence on the flow field. The approach is applied to a weakly-convective dense particulate system under the Rayleigh number containing more than 4000 particles (solid volume fraction 42.8%) of various conductivities. With highly-conductive particles (in comparison to the ambient fluid), local downward convection of a large-scale vortical flow strengthens the conductive heat flux near the bottom hot wall in the counter-convective direction by the increase of the vertical temperature gradient, and the observation of the spatial extension of the heat flux lines indicates that the increase of the solid volume fraction near the hot wall further strengthens the conductive heat flux. The paired upward convection causes strengthened conductive heat flux near the top cold wall by the same increase mechanism. The above interplay of the local heat fluxes in the dense solid-dispersed media are found to influence on the formation and transition of the large-scale vortical structures through the distribution of the moment of buoyancy in a horizontal plane. An analytical model for a low-dimensional vortex system shows that buoyancy gradient and vorticity diffusion could determine the time-development of the large-scale vortical structure.
DC.rights	© 2018 Elsevier Ltd. This manuscript version is made available under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International license.
DC.format	79017
citation_title	Vortical flow patterns by the cooperative effect of convective and conductive heat transfers in particle-dispersed natural convection
citation_author	Gu, Jingchen
	Takeuchi, Shintaro
	Fukada, Toshiaki
	Kajishima, Takeo
citation_publisher	Elsevier
citation_language	英語
citation_date	2019-03
citation_journal_title	International Journal of Heat and Mass Transfer
citation_volume	130
citation_firstpage	946
citation_lastpage	959
citation_doi	https://doi.org/10.1016/j.ijheatmasstransfer.2018.10.138
citation_public_url	https://hdl.handle.net/11094/79017

Vortical flow patterns by the cooperative effect of convective and conductive heat transfers in particle-dispersed natural convection

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