scholarly journals An effective thermal conductivity model for fractal porous media with rough surfaces

2019 ◽  
Vol 3 (2) ◽  
pp. 149-155 ◽  
Author(s):  
Xuan Qin ◽  
Yingfang Zhou ◽  
Agus Pulung Sasmito
Keyword(s):  
Thermal Conductivity ◽  
Porous Media ◽  
Effective Thermal Conductivity ◽  
Rough Surfaces ◽  
Conductivity Model ◽  
Thermal Conductivity Model

Fractal Model for Thermal Conductivity of Wetting, Fibrous Porous Media

2012 ◽  
Vol 496 ◽  
pp. 12-16
Author(s):  
Fang Long Zhu ◽  
De Hong Xia ◽  
Yu Zhou
Keyword(s):  
Thermal Conductivity ◽  
Porous Media ◽  
Fractal Dimension ◽  
Effective Thermal Conductivity ◽  
Fractal Model ◽  
Self Similarity ◽  
Conductivity Model ◽  
Electrical Analogy ◽  
Fibrous Porous Media ◽  
Thermal Conductivity Model

The current paper deals with the fractal effective thermal conductivity model for fibrous porous media containing unsaturated water moisture. The model is based on the thermal-electrical analogy and statistical self-similarity of porous media. The fractal effective thermal conductivity model can be expressed as a function of the pore structure (fractal dimension) and architectural parameters of porous media. It is expected that the model will be helpful in the evaluation of thermal comfort for textiles in the whole range of porosity.

Improvement of core effective thermal conductivity model of GAMMA+code based on CFD analysis

2013 ◽  
Vol 59 ◽  
pp. 157-168 ◽  
Author(s):  
Su-Jong Yoon ◽  
Dong-Ho Shin ◽  
Hong-Sik Lim ◽  
Goon-Cherl Park ◽  
Taewan Kim
Keyword(s):  
Thermal Conductivity ◽  
Effective Thermal Conductivity ◽  
Cfd Analysis ◽  
Conductivity Model ◽  
Thermal Conductivity Model

scholarly journals New Equivalent Thermal Conductivity Model for Size-Dependent Convection-Driven Melting of Spherically Encapsulated Phase Change Material

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4752
Author(s):  
Feng Hou ◽  
Shihao Cao ◽  
Hui Wang
Keyword(s):  
Thermal Conductivity ◽  
Phase Change ◽  
Effective Thermal Conductivity ◽  
Matrix Material ◽  
Melting Process ◽  
Melting Time ◽  
Equivalent Thermal Conductivity ◽  
Melting Front ◽  
Conductivity Model ◽  
Thermal Conductivity Model

Spherically encapsulated phase change materials (PCMs) are extensively incorporated into matrix material to form composite latent heat storage system for the purposes of saving energy, reducing PCM cost and decreasing space occupation. Although the melting of PCM sphere has been studied comprehensively by experimental and numerical methods, it is still challenging to quantitatively depict the contribution of complex natural convection (NC) to the melting process in a practically simple and acceptable way. To tackle this, a new effective thermal conductivity model is proposed in this work by focusing on the total melting time (TMT) of PCM, instead of tracking the complex evolution of solid–liquid interface. Firstly, the experiment and finite element simulation of the constrained and unconstrained meltings of paraffin sphere are conducted to provide a deep understanding of the NC-driven melting mechanism and exhibit the difference of melting process. Then the dependence of NC on the particle size and heating temperature is numerically investigated for the unconstrained melting which is closer to the real-life physics than the constrained melting. Subsequently, the contribution of NC to the TMT is approximately represented by a simple effective thermal conductivity correlation, through which the melting process of PCM is simplified to involve heat conduction only. The effectiveness of the equivalent thermal conductivity model is demonstrated by rigorous numerical analysis involving NC-driven melting. By addressing the TMT, the present correlation thoroughly avoids tracking the complex evolution of melting front and would bring great convenience to engineering applications.

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