scholarly journals Estimating the effective conductivity for ellipse-inclusion model with Kapitza thermal resistance

2021 ◽  
Vol 8 ◽  
pp. 16
Author(s):  
Van-Luat Nguyen
Keyword(s):  
Thermal Conductivity ◽  
Fourier Transform ◽  
Thermal Resistance ◽  
Effective Conductivity ◽  
Dimensional Space ◽  
Imperfect Interface ◽  
Two Dimensional ◽  
Imperfect Interfaces ◽  
Equivalent Inclusion ◽  
Resistance Model

The ellipse assemblage model with imperfect interface has quite complex microstructure, that can be considered an extension of the circle assemblage model with imperfect interfaces. The paper introduces an approximate method for computing the effective conductivity of isotropic composites with imperfect interfaces in two-dimensional space. Based on the coated-ellipse assemblage model and the equivalent inclusion approximation, one can determine the effective thermal conductivity of the composites. The polarization approximation is given in an explicit form (PEK) and this method will be applied to calculate the effective conductivity of the composite with Kapitza thermal resistance model. The PEK result will have compared with the Fast Fourier Transform (FFT) simulation and Hashin-strikman bounds (HS).

scholarly journals Effective conductivity of isotropic composite with Kapitza thermal resistance

2018 ◽  
Author(s):  
Kien Trung Nguyen ◽  
Luat Van Nguyen ◽  
Chinh Duc Pham
Keyword(s):  
Thermal Conductivity ◽  
Thermal Resistance ◽  
Effective Thermal Conductivity ◽  
Effective Conductivity ◽  
Imperfect Interface ◽  
Simple Method ◽  
Isotropic Composite ◽  
Equivalent Inclusion

A simple method is introduced for computing the effective conductivity of isotropic composite with imperfect interface. Based on the doubly-coated circle assemblage model, one can determine the effective thermal conductivity of the composite. The application of this model to the composite with imperfect interface of the Kapitza's type is proposed. The results obtained were compared with the FFT simulation and the equivalent inclusion approximation in 2D show the effectiveness of the methods.

scholarly journals Size dependent of the effective conductivity of composite with imperfect interfaces

2020 ◽  
Author(s):  
Nguyen Trung Kien
Keyword(s):  
Fourier Transform ◽  
Size Effect ◽  
Effective Properties ◽  
Effective Conductivity ◽  
Imperfect Interface ◽  
Numerical Results ◽  
Imperfect Interfaces ◽  
Size Dependent ◽  
Equivalent Inclusion ◽  
The Fourier Transform

Based on the circle assemblage model, the effective properties of the inclusion with imperfect interface are derived. The equivalent inclusion is incorporated in the Fourier Transform algorithm to determine the effective conductivity of the composite with lowly conducting or highly conducting interface. The size effect is considered for both cases. Numerical results are provided to illustrate the dependence of the effective conductivity on the size of inhomogeneities.

Computational Evaluation of Effective Conductivity of Particulate Composites with Imperfect Interfaces

2009 ◽  
Vol 631-632 ◽  
pp. 35-40
Author(s):  
M. Zhang ◽  
Peng Cheng Zhai ◽  
Qing Jie Zhang
Keyword(s):  
Thermal Conductivity ◽  
Effective Thermal Conductivity ◽  
Effective Properties ◽  
Effective Conductivity ◽  
Three Dimensional ◽  
Particulate Composite ◽  
Imperfect Interface ◽  
Particulate Composites ◽  
Imperfect Interfaces ◽  
Volume Fractions

This paper is aimed to numerically evaluate the effective thermal conductivity of randomly distributed spherical particle composite with imperfect interface between the constituents. A numerical homogenization technique based on the finite element method (FEM) with representative volume element (RVE) was used to evaluate the effective properties with periodic boundary conditions. Modified random sequential adsorption algorithm (RSA) is applied to generate the three dimensional RVE models of randomly distributed spheres of identical size with the volume fractions up to 50%. Several investigations have been conducted to estimate the influence of the imperfect interfaces on the effective conductivity of particulate composite. Numerical results reveal that for the given composite, due to the existence of an interfacial thermal barrier resistance, the effective thermal conductivity depends not only on the volume fractions of the particle but on the particle size.

Optimization of Pass Design of Bidirectional Thermal-Insulation Bricks

2014 ◽  
Vol 1008-1009 ◽  
pp. 1348-1351
Author(s):  
Sha Sha Dong ◽  
Xiao Ping Feng
Keyword(s):  
Thermal Conductivity ◽  
Thermal Resistance ◽  
Thermal Insulation ◽  
Thermal Performance ◽  
Element Model ◽  
Two Dimensional ◽  
Pass Design ◽  
Dimensional Finite Element ◽  
The Impact ◽  
Better Than

The thermal performance of perforated brick is affected by various factors, thermal conductivity, the holes rates, the pass design and etc. included. In order to analyze the impact of the pass design on the thermal performance of bidirectional thermal insulation bricks, the two-dimensional finite element model was developed using ANSYS. The simulated result shows that existence of vertical holes can enhance the thermal resistance in the longer dimension of the perforated brick. Under the condition of the same holes rates, narrowing the width of the vertical holes helps to improve the thermal resistance in the shorter dimension of the perforated brick. The function of these blocks are extremely influenced by the distribution of the vertical holes, the concentrated better than the both-sided when it comes to advancing the whole function.

Effective Thermal Conductivity of Composites with Different Particle Geometries and Interfacial Thermal Resistance

2010 ◽  
Vol 152-153 ◽  
pp. 269-273
Author(s):  
Mei Zhang ◽  
Peng Cheng Zhai
Keyword(s):  
Thermal Conductivity ◽  
Thermal Resistance ◽  
Effective Thermal Conductivity ◽  
Imperfect Interface ◽  
Interfacial Thermal Resistance ◽  
Surface Integral ◽  
Two Phase ◽  
Self Consistent ◽  
Consistent Method ◽  
Barrier Resistance

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.

PCB Trace Thermal Analysis and Effective Conductivity

1992 ◽  
Vol 114 (4) ◽  
pp. 413-419 ◽  
Author(s):  
T. F. Lemczyk ◽  
B. L. Mack ◽  
J. R. Culham ◽  
M. M. Yovanovich
Keyword(s):  
Thermal Conductivity ◽  
Thermal Analysis ◽  
Heat Source ◽  
Printed Circuit Board ◽  
Effective Conductivity ◽  
Cell Model ◽  
Homogeneous Medium ◽  
Electrical Current ◽  
Circuit Board ◽  
Two Dimensional

The electrical current carrying capability of a surface or buried trace located within a fiberglass printed circuit board (PCB), is of important interest in the microelectronics industry. The maximum allowable trace power, hence local integrity and maximum allowable operating temperature, will depend on several parameters including the circuit board thermal conductivity, thickness, trace size and location. A two-dimensional, steady-state thermal conduction analysis is made on a finite, plane homogeneous medium (PCB), to examine the trace behavior. The trace is modeled as a zero-thickness, strip heat source with specified uniform temperature, and it’s position in the medium is varied. A two-dimensional thermal analysis is also performed on a multilayered cell model with finite heat source, to establish an accurate, effective thermal conductivity for a typical PCB. Results are tabulated and presented graphically for both the two-dimensional trace and effective conductivity models.

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