Heat Conduction in Porous Media Characterized by Fractal Geometry
Fractal geometry (fractional Brownian motion—FBM) is introduced to characterize the pore distribution of porous material. Based on this fractal characterization, a mathematical model of heat conduction is presented to study heat conduction behaviors in porous material with a focus on effective therm...
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| Format: | Article |
| Language: | English |
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MDPI AG
2017-08-01
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| Series: | Energies |
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| Online Access: | https://www.mdpi.com/1996-1073/10/8/1230 |
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| author | Zilong Deng Xiangdong Liu Yongping Huang Chengbin Zhang Yongping Chen |
| author_facet | Zilong Deng Xiangdong Liu Yongping Huang Chengbin Zhang Yongping Chen |
| author_sort | Zilong Deng |
| collection | DOAJ |
| description | Fractal geometry (fractional Brownian motion—FBM) is introduced to characterize the pore distribution of porous material. Based on this fractal characterization, a mathematical model of heat conduction is presented to study heat conduction behaviors in porous material with a focus on effective thermal conductivity. The role of pore structure on temperature distribution and heat flux is examined and investigated for fractal porous material. In addition, the effects of fractal dimension, porosity, and the ratio of solid-matrix-to-fluid-phase thermal conductivity (ks/kf) on effective thermal conductivity are evaluated. The results indicate that pore structure has an important effect on heat conduction inside porous material. Increasing porosity lowers thermal conductivity. Even when porosity remains constant, effective thermal conductivity is affected by the fractal dimensions of the porous material. For porous material, the heat conduction capability weakens with increased fractal dimension. Additionally, fluid-phase thermal conduction across pores is effective in porous material only when ks/kf < 50. Otherwise, effective thermal conductivity for porous material with a given pore structure depends primarily on the thermal conductivity of the solid matrix. |
| first_indexed | 2024-04-11T21:58:59Z |
| format | Article |
| id | doaj.art-e77ad405d8974c08bf4dbf52937e67ce |
| institution | Directory Open Access Journal |
| issn | 1996-1073 |
| language | English |
| last_indexed | 2024-04-11T21:58:59Z |
| publishDate | 2017-08-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Energies |
| spelling | doaj.art-e77ad405d8974c08bf4dbf52937e67ce2022-12-22T04:01:00ZengMDPI AGEnergies1996-10732017-08-01108123010.3390/en10081230en10081230Heat Conduction in Porous Media Characterized by Fractal GeometryZilong Deng0Xiangdong Liu1Yongping Huang2Chengbin Zhang3Yongping Chen4Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing 210096, Jiangsu, ChinaSchool of Hydraulic, Energy and Power Engineering, Yangzhou University, Yangzhou 225127, Jiangsu, ChinaKey Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing 210096, Jiangsu, ChinaKey Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing 210096, Jiangsu, ChinaJiangsu Key Laboratory of Micro and Nano Heat Fluid Flow Technology and Energy Application, School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, Jiangsu, ChinaFractal geometry (fractional Brownian motion—FBM) is introduced to characterize the pore distribution of porous material. Based on this fractal characterization, a mathematical model of heat conduction is presented to study heat conduction behaviors in porous material with a focus on effective thermal conductivity. The role of pore structure on temperature distribution and heat flux is examined and investigated for fractal porous material. In addition, the effects of fractal dimension, porosity, and the ratio of solid-matrix-to-fluid-phase thermal conductivity (ks/kf) on effective thermal conductivity are evaluated. The results indicate that pore structure has an important effect on heat conduction inside porous material. Increasing porosity lowers thermal conductivity. Even when porosity remains constant, effective thermal conductivity is affected by the fractal dimensions of the porous material. For porous material, the heat conduction capability weakens with increased fractal dimension. Additionally, fluid-phase thermal conduction across pores is effective in porous material only when ks/kf < 50. Otherwise, effective thermal conductivity for porous material with a given pore structure depends primarily on the thermal conductivity of the solid matrix.https://www.mdpi.com/1996-1073/10/8/1230heat conductionthermal conductivityporous materialfractal |
| spellingShingle | Zilong Deng Xiangdong Liu Yongping Huang Chengbin Zhang Yongping Chen Heat Conduction in Porous Media Characterized by Fractal Geometry Energies heat conduction thermal conductivity porous material fractal |
| title | Heat Conduction in Porous Media Characterized by Fractal Geometry |
| title_full | Heat Conduction in Porous Media Characterized by Fractal Geometry |
| title_fullStr | Heat Conduction in Porous Media Characterized by Fractal Geometry |
| title_full_unstemmed | Heat Conduction in Porous Media Characterized by Fractal Geometry |
| title_short | Heat Conduction in Porous Media Characterized by Fractal Geometry |
| title_sort | heat conduction in porous media characterized by fractal geometry |
| topic | heat conduction thermal conductivity porous material fractal |
| url | https://www.mdpi.com/1996-1073/10/8/1230 |
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