scholarly journals Constructal Design of an Arrow-Shaped High Thermal Conductivity Channel in a Square Heat Generation Body

Entropy ◽  
2020 ◽  
Vol 22 (4) ◽  
pp. 475 ◽  
Author(s):  
Fengyin Zhang ◽  
Huijun Feng ◽  
Lingen Chen ◽  
Jiang You ◽  
Zhihui Xie
Keyword(s):  
Thermal Conductivity ◽  
Heat Conduction ◽  
Heat Generation ◽  
Degrees Of Freedom ◽  
High Thermal Conductivity ◽  
Maximum Temperature ◽  
Thermal Conductivity Ratio ◽  
Maximum Temperature Difference ◽  
Conduction Model ◽  
Three Degrees Of Freedom

A heat conduction model with an arrow-shaped high thermal conductivity channel (ASHTCC) in a square heat generation body (SHGB) is established in this paper. By taking the minimum maximum temperature difference (MMTD) as the optimization goal, constructal designs of the ASHTCC are conducted based on single, two, and three degrees of freedom optimizations under the condition of fixed ASHTCC material. The outcomes illustrate that the heat conduction performance (HCP) of the SHGB is better when the structure of the ASHTCC tends to be flat. Increasing the thermal conductivity ratio and area fraction of the ASHTCC material can improve the HCP of the SHGB. In the discussed numerical examples, the MMTD obtained by three degrees of freedom optimization are reduced by 8.42% and 4.40%, respectively, compared with those obtained by single and two degrees of freedom optimizations. Therefore, three degrees of freedom optimization can further improve the HCP of the SHGB. Compared the HCPs of the SHGBs with ASHTCC and the T-shaped one, the MMTD of the former is reduced by 13.0%. Thus, the structure of the ASHTCC is proven to be superior to that of the T-shaped one. The optimization results gained in this paper have reference values for the optimal structure designs for the heat dissipations of various electronic devices.

Introduce a novel configurationof microchannel andhigh-conductivity insertsfor cooling of disc-shaped electronic components

2019 ◽  
Vol 30 (6) ◽  
pp. 2845-2859 ◽  
Author(s):  
Reza Dadsetani ◽  
Ghanbar Ali Sheikhzadeh ◽  
Mohammad Reza Hajmohammadi ◽  
Mohammad Reza Safaei
Keyword(s):  
Thermal Conductivity ◽  
Hybrid Method ◽  
High Thermal Conductivity ◽  
Maximum Temperature ◽  
Thermal Conductivity Ratio ◽  
Conductivity Ratio ◽  
Electronic Components ◽  
Content Type ◽  
Micro Pump ◽  
Hybrid Configuration

Purpose Electronic components’ efficiency is the cornerstone of technology progress. The cooling process used for electronic components plays a main role in their performance. Embedded high-conductivity material and provided microchannel heat sink are two common cooling methods. The former is expensive to implement while the latter needs micro-pump, which consumes energy to circulate the flow. The aim of this study is providing a new configuration and method for improving the performance of electronic components. Design/methodology/approach To manage these challenges and improve the cooling efficiency, a novel method named Hybrid is presented here. Each method's performance has been investigated, and the results are widely compared with others. Considering the micro-pump power, the supply of the microchannel flow and the thermal conductivity ratio (thermal conductivity ratio is defined as the ratio of thermal conductivity of high thermal conductivity material to the thermal conductivity of base solid), the maximum disk temperature of each method was evaluated and compared to others. Findings The results indicated that the Hybrid method can reduce the maximum disk temperature up to 90 per cent compared to the embedded high thermal conductivity at the same thermal conductivity ratio. Moreover, the Hybrid method further reduces the maximum disk temperature up to 75 per cent compared to the microchannel, at equivalent power consumption. Originality/value The information in this research is presented in such a way that designers can choose the desired composition, the limited amount of consumed energy and the high temperature of the component. According to the study of radial-hybrid configuration, the different ratio of microchannel and materials with a high thermal conductivity coefficient in the constant cooling volume was investigated. The goal of the investigation was to decrease the maximum temperature of a plate on constant energy consumption. This aim has been obtained in the radial-hybrid configuration.

Numerical Simulation of Thermal Conductivity of Nanofluids

2010 ◽  
Author(s):  
Jing Fan ◽  
Liqiu Wang
Keyword(s):  
Thermal Conductivity ◽  
Heat Conduction ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Interfacial Thermal Resistance ◽  
Thermal Conductivity Ratio ◽  
Radius Of Gyration ◽  
Particle Volume ◽  
Geometrical Structures ◽  
Conductivity Enhancement

The recent first-principle model shows a dual-phase-lagging heat conduction in nanofluids at the macroscale. The macroscopic heat-conduction behavior and the thermal conductivity of nanofluids are determined by their molecular physics and microscale physics. We examine numerically effects of particle-fluid thermal conductivity ratio, particle volume fraction, shape, aggregation, and size distribution on macroscale thermal properties for nine types of nanofluids, without considering the interfacial thermal resistance and dynamic processes on particle-fluid interfaces and particle-particle contacting surfaces. The particle radius of gyration and non-dimensional particle-fluid interfacial area in the unit cell are two very important parameters in characterizing the effect of particles’ geometrical structures on thermal conductivity of nanofluids. Nanofluids containing cross-particle networks have conductivity which practically reaches the Hashin-Shtrikman bounds. Moreover, particle aggregation influences the effective thermal conductivity only when the distance between particles is less than the particle dimension. Uniformly-sized particles are desirable for the conductivity enhancement, although to a limited extent.

Design and Optimization of a Composite Heat Spreader to Improve the Thermal Management of a 3D Integrated Circuit

2021 ◽  
Author(s):  
Andisheh Tavakoli ◽  
Kambiz Vafai
Keyword(s):  
Thermal Conductivity ◽  
Heat Sink ◽  
Variable Temperature ◽  
Heat Removal ◽  
High Conductivity ◽  
High Thermal Conductivity ◽  
Maximum Temperature ◽  
Optimal Distribution ◽  
Heat Spreader ◽  
The Impact

Abstract The present study analyzes the optimal distribution of a limited amount of high thermal conductivity material to enhance the heat removal of circular 3D integrated circuits, IC. The structure of the heat spreader is designed as a composite of high thermal conductivity (Boron Arsenide) and moderate thermal conductivity (copper) materials. The volume ratio of high-conductivity inserts to the total volume of the spreader is set at a fixed pertinent ratio. Two different boundary conditions of constant and variable temperature are considered for the heat sink. To examine the impact of adding high-conductivity inserts on the cooling performance of the heat spreader, various patterns of the single and double ring inserts are studied. A parametric study is performed to find the optimal location of the rings. Moreover, the optimal distribution of the high-conductivity material between the inner and outer rings is found. The results show that for the optimal conditions, the maximum temperature of the 3D IC is reduced up to 10%; while the size of the heat sink, and heat spreader can be diminished by as much as 200%.

scholarly journals A Fractional Single-Phase-Lag Model of Heat Conduction for Describing Propagation of the Maximum Temperature in a Finite Medium

Entropy ◽  
2018 ◽  
Vol 20 (11) ◽  
pp. 876 ◽  
Author(s):  
Stanisław Kukla ◽  
Urszula Siedlecka
Keyword(s):  
Heat Conduction ◽  
Hollow Cylinder ◽  
Single Phase ◽  
Heat Conduction Problem ◽  
Expansion Method ◽  
Maximum Temperature ◽  
Phase Lag ◽  
Conduction Model ◽  
Laplace Transform Technique ◽  
Finite Medium

In this paper, an investigation of the maximum temperature propagation in a finite medium is presented. The heat conduction in the medium was modelled by using a single-phase-lag equation with fractional Caputo derivatives. The formulation and solution of the problem concern the heat conduction in a slab, a hollow cylinder, and a hollow sphere, which are subjected to a heat source represented by the Robotnov function and a harmonically varying ambient temperature. The problem with time-dependent Robin and homogenous Neumann boundary conditions has been solved by using an eigenfunction expansion method and the Laplace transform technique. The solution of the heat conduction problem was used for determination of the maximum temperature trajectories. The trajectories and propagation speeds of the temperature maxima in the medium depend on the order of fractional derivatives occurring in the heat conduction model. These dependencies for the heat conduction in the hollow cylinder have been numerically investigated.

Numerical investigation of fast precooling of a cylindrical food product based on the hyperbolic heat conduction model

2013 ◽  
Vol 23 (6) ◽  
pp. 960-978 ◽  
Author(s):  
Mohammed Q. Al‐Odat
Keyword(s):  
Heat Conduction ◽  
Heat Generation ◽  
Internal Heat ◽  
Food Product ◽  
Heat Diffusion ◽  
Numerical Code ◽  
Hyperbolic Model ◽  
Hyperbolic Heat Conduction ◽  
Conduction Model ◽  
Content Type

PurposeIn this study, the purpose was to introduce two‐dimensional hyperbolic heat conduction equations in order to simulate the fast precooling process of a cylindrically shaped food product with internal heat generation. A modified model for internal heat generation due to respiration in the food product was proposed to take the effect of relaxation time into account. The obtained governing equations were solved numerically using an efficient finite difference technique. The influence of Biot number and heat generation parameters on thermal characteristics was examined and discussed. The results based on hyperbolic model were compared with the classical parabolic heat diffusion model. The present numerical code was validated via comparison with analytical solution and a good agreement was found.Design/methodology/approachThe obtained governing equations were solved numerically using an efficient finite difference technique.FindingsThe influence of Biot number and heat generation parameters on thermal characteristics was examined and discussed. The results based on hyperbolic model were compared with the classical parabolic heat diffusion model. The present numerical code was validated via comparison with analytical solution and a good agreement was found.Originality/valueTwo‐dimensional analysis of fast precooling of cylindrical food product based on hyperbolic heat conduction model has not been investigated yet.

Thermal Aspects of Grinding: The Effect of the Wheel Bond on Heat Transfer to an Abrasive Grain

1991 ◽  
Vol 113 (4) ◽  
pp. 395-401 ◽  
Author(s):  
M. W. Harris ◽  
A. S. Lavine
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Thermal Properties ◽  
Heat Conduction ◽  
Beneficial Effect ◽  
Surface Temperature ◽  
Thermal Damage ◽  
High Thermal Conductivity ◽  
Abrasive Grain ◽  
Grain Surface

Heat generated during grinding can cause thermal damage to the workpiece and wheel. It is therefore important to understand the thermal aspects of grinding. This paper addresses heat conduction into the wheel, by considering a single abrasive grain in contact with the workpiece. In particular, the effect of the bond material on conduction into the grain is investigated. The results for the grain surface temperature are given in terms of parameters describing the geometry and thermal properties of the grain and bond. The beneficial effect of a high thermal conductivity for both the grain and the bond is clearly demonstrated.

Enhancement of heat conduction in carbon nanotubes filled with fullerene molecules

2015 ◽  
Vol 17 (41) ◽  
pp. 27520-27526 ◽  
Author(s):  
Liu Cui ◽  
Yanhui Feng ◽  
Xinxin Zhang
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Mass Transfer ◽  
Heat Conduction ◽  
High Thermal Conductivity ◽  
Low Frequencies

C60-encapsulation-induced high thermal conductivity of carbon nanopeapods owing to phonon couplings at low frequencies and enhancement in mass transfer.

A Study on Storing Process of Thermoforming Using Finite Difference Method

2011 ◽  
Vol 314-316 ◽  
pp. 571-575
Author(s):  
Zhen Zhe Li ◽  
Gui Ying Shen ◽  
Xiao Qian Wang ◽  
Mei Qin Li ◽  
Yun De Shen
Keyword(s):  
Thermal Conductivity ◽  
Temperature Distribution ◽  
Finite Difference Method ◽  
Initial Temperature ◽  
Thickness Distribution ◽  
Time Dependent ◽  
Maximum Temperature ◽  
Uniform Thickness ◽  
Maximum Temperature Difference

Obtaining a uniform thickness of the final product using thermoforming is difficult, and the thickness distribution depends strongly on the distribution of the sheet temperature. In this paper, the time-dependent temperature distribution of the total sheets in the storing process was studied because the temperature after the storing process is the initial temperature of the preheating process. An analysis code for simulating the storing process was developed under the condition that the thermal conductivity caused by contact resistance between sheets was assumed as a large value. In this study, the number of sheets in the storing room was adjusted for finding out the effect of it. The analysis results show that maximum temperature difference between sheets was significantly different when adjusting the number of sheets in the storing room. The temperature distribution of the total sheets and the method for analysis in this study will be used to optimize the storing process for higher quality of final products.

Sign in / Sign up

Export Citation Format

Share Document