Heat Conduction in Two-Phase Composite Materials with Three-Dimensional Microstructures and Interfacial Thermal Resistance

Author(s):  
Carlos Frederico Matt ◽  
Manuel Ernani Cruz
2021 ◽  
Author(s):  
Xiao-jian Wang ◽  
Liang-Bi Wang

Abstract The most common non-granular fillers are sheet and fiber. When they are distributed along the heat flux direction, the thermal conductivity of composite increases greatly. Meanwhile, the filler contact also has large effect on the thermal conductivity. However, the effect of filler contact on the thermal conductivity of composite with directional fillers has not been investigated. In this paper, the combined effects of filler contact, content and orientation are investigated. The results show that the effect of filler orientation on the thermal conductivity is greater than filler contact in low filler content, and exact opposite in high filler content. The effect of filler contact on fibrous and sheet fillers is far greater than cube and sphere fillers. This rule is affected by the filler contact. The filler content of 8% is the ideal percolation threshold of composite with fibrous and sheet filler. It is lower than cube filler and previous reports. The space for thermal conductivity growth of composite with directional filler is still very large. The effect of interfacial thermal resistance should be considered in predicting the thermal conductivity of composite under high Rc (>10-4).


Author(s):  
Koji Nishi ◽  
Tomoyuki Hatakeyama ◽  
Shinji Nakagawa ◽  
Masaru Ishizuka

The thermal network method has a long history with thermal design of electronic equipment. In particular, a one-dimensional thermal network is useful to know the temperature and heat transfer rate along each heat transfer path. It also saves computation time and/or computation resources to obtain target temperature. However, unlike three-dimensional thermal simulation with fine pitch grids and a three-dimensional thermal network with sufficient numbers of nodes, a traditional one-dimensional thermal network cannot predict the temperature of a microprocessor silicon die hot spot with sufficient accuracy in a three-dimensional domain analysis. Therefore, this paper introduces a one-dimensional thermal network with average temperature nodes. Thermal resistance values need to be obtained to calculate target temperature in a thermal network. For this purpose, thermal resistance calculation methodology with simplified boundary conditions, which calculates thermal resistance values from an analytical solution, is also introduced in this paper. The effectiveness of the methodology is explored with a simple model of the microprocessor system. The calculated result by the methodology is compared to a three-dimensional heat conduction simulation result. It is found that the introduced technique matches the three-dimensional heat conduction simulation result well.


Energies ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 796 ◽  
Author(s):  
Shahin Mohammad Nejad ◽  
Masoud Bozorg Bigdeli ◽  
Rajat Srivastava ◽  
Matteo Fasano

Because of their high thermal conductivity, graphene nanoribbons (GNRs) can be employed as fillers to enhance the thermal transfer properties of composite materials, such as polymer-based ones. However, when the filler loading is higher than the geometric percolation threshold, the interfacial thermal resistance between adjacent GNRs may significantly limit the overall thermal transfer through a network of fillers. In this article, reverse non-equilibrium molecular dynamics is used to investigate the impact of the relative orientation (i.e., horizontal and vertical overlap, interplanar spacing and angular displacement) of couples of GNRs on their interfacial thermal resistance. Based on the simulation results, we propose an empirical correlation between the thermal resistance at the interface of adjacent GNRs and their main geometrical parameters, namely the normalized projected overlap and average interplanar spacing. The reported correlation can be beneficial for speeding up bottom-up approaches to the multiscale analysis of the thermal properties of composite materials, particularly when thermally conductive fillers create percolating pathways.


1987 ◽  
Vol 12 (4) ◽  
pp. 239-250 ◽  
Author(s):  
R. A. Tatara

A general thermal model to calculate the thermal resistance of a power module having rectangular die and layers has been constructed. The model incorporates a finite element computer program to solve for three-dimensional heat conduction. Effects of voids in the solder regions are included. A sample case is analyzed, and a comparison is made to a recent study.


Author(s):  
Murat Barisik ◽  
Ziyuan Shi ◽  
Ali Beskok

Heat conduction between two parallel solid walls separated by liquid argon is investigated using three-dimensional molecular dynamics (MD) simulations. Liquid argon molecules confined in silver and graphite nano-channels are examined separately. Heat flux and temperature distribution within the nano-channels are calculated by maintaining a fixed temperature difference between the two solid surfaces. Temperature profiles are linear sufficiently away from the walls, and heat transfer in liquid argon obeys the Fourier law. Temperature jump due to the interface thermal resistance (i.e., Kapitza length) is characterized as a function of the wall temperature. MD results enabled development of a phenomenological model for the Kapitza length, which is utilized as the coefficient of a Navier-type temperature jump boundary condition using continuum heat conduction equation. Analytical solution of this model results in successful predictions of temperature distribution in liquid-argon confined in silver and graphite nano-channels as thin as 7 nm and 3.57 nm, respectively.


1988 ◽  
Vol 110 (2) ◽  
pp. 110-112 ◽  
Author(s):  
Seiichi Nomura ◽  
A. Haji-Sheikh

This paper addresses a generalized analytical procedure for transient heat conduction in composite materials of two- and three-dimensional finite region. The Galerkin method is employed to obtain temperature field in closed form with the utilization of symbolic algebra software such as REDUCE or MACSYMA. It is found from illustrative examples that the proposed method yields accurate and effective predictions of temperature fields for which purely numerical methods such as finite element or finite difference are not suitable.


2010 ◽  
Vol 152-153 ◽  
pp. 269-273
Author(s):  
Mei Zhang ◽  
Peng Cheng Zhai

A new micromechanical method, the weighted residual self-consistent method (WRSCM) is developed to study the effective thermal conductivity of two-phase composites with different particle geometries in the presence of a thermal barrier resistance at the interface between constituents. The imperfect interface involves the continuity of the normal flux but allow for a finite temperature differences across the interface. Within the framework of self-consistent scheme, the effective thermal conductivity of two-phase composite is obtained using numerical iterative method on the basis of a surface integral of temperature over the imperfect interfaces. Numerical results show that for the given composite system, due to the existence of an interfacial thermal resistance, the particle geometries have significant impact on the effective thermal conductivity of composites.


2012 ◽  
Vol 548 ◽  
pp. 123-127
Author(s):  
Xiao Tuo Li ◽  
Xin Yu Fan ◽  
Ying Dan Zhu ◽  
Juan Li

A three-dimensional computational model based on the finite element method was developed to predict the thermal properties of randomly distributed multi-walled carbon nanotube (MWCNT)/polymer composites. The numerical results agree very well with the experimental data for MWCNT/epoxy composites with the MWCNT loading below ~10 vol% at the interfacial thermal resistance of ~1.0×10-8 m2K/W, which may give insight into the relationship between the thermal behavior of MWCNT-matrix interfaces and the thermal conductivity of composites. This model is also a useful tool to evaluate the effects of MWCNT-matrix interfacial thermal resistance, volume fraction, thermal conductivity and diameter of MWCNTs on the thermal conductivity of other types of MWCNT/ polymer composites.


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