Yongtong Li¹, Liang Gong^{1, *}, Hui Lu¹, Dexin Zhang¹, Bin Ding¹

CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.2, pp. 895-912, 2020, DOI:10.32604/cmes.2020.09009 - 01 May 2020

Abstract In the present study, the thermal performance of metal foam heat sink was numerically investigated by adopting the local thermal non-equilibrium (LTNE) model and local thermal equilibrium (LTE) model. Temperature field distributions and temperature difference field distributions of solid and fluid phases were presented. Detailed thermal performance comparisons based on the LTE and LTNE models were evaluated by considering the effects of the relevant metal foam morphological and channel geometrical parameters. Results indicate that a distinct temperature difference exists between the solid and fluid phases when the LTNE effect is pronounced. The average Nusselt numbers… More >

Jin Wang^{1, 2, 3}, Yu Gao², Chang Zhou², R. Simon Sherratt⁴, Lei Wang^{5, *}

CMC-Computers, Materials & Continua, Vol.62, No.2, pp. 695-711, 2020, DOI:10.32604/cmc.2020.08674

Abstract Wireless Sensor Networks (WSNs) are usually formed with many tiny sensors which are randomly deployed within sensing field for target monitoring. These sensors can transmit their monitored data to the sink in a multi-hop communication manner. However, the ‘hot spots’ problem will be caused since nodes near sink will consume more energy during forwarding. Recently, mobile sink based technology provides an alternative solution for the long-distance communication and sensor nodes only need to use single hop communication to the mobile sink during data transmission. Even though it is difficult to consider many network metrics such… More >

Emran Khoshrouye Ghiasi, Reza Saleh^*

Frontiers in Heat and Mass Transfer, Vol.12, pp. 1-7, 2019, DOI:10.5098/hmt.12.4

Abstract In this paper, two-dimensional magnetohydrodynamic (MHD) flow of Casson fluid over a fixed plate under non-uniform heat source/sink and Joule heating is analyzed by the homotopy analysis method (HAM). The governing boundary-layer equations have been reduced to the ordinary differential equations (ODEs) through the similarity variables. The current HAM-series solution is compared and successfully validated by the previous studies. Furthermore, the effects of thermo-physical parameters on the current solution are precisely examined. It is found that the skin friction coefficient and local Nusselt number are greatly affected by the Hartmann number. It can be concluded More >

Chadwick D. Sevart^* , Theodore L. Bergman

Frontiers in Heat and Mass Transfer, Vol.13, pp. 1-18, 2019, DOI:10.5098/hmt.13.18

Abstract A design approach is proposed and demonstrated to identify desirable two-dimensional solid geometries, cooled by natural convection, that offer superior thermal performance in terms of reduced overall (conduction-convection) thermal resistance. The approach utilizes (i) heat transfer modeling in conjunction with (ii) various novel shape evolution rules. Predictions demonstrate the evolution of the solid shape and associated reduction of the overall thermal resistance. Parametric simulations reveal the dependence of the predicted solid shape on the evolution rule employed, the thermal conductivity of the solid material, and the strength of advection within the fluid. More >

G. Nagaraju^a,∗ , Mahesh Garvandha^b, J.V. Ramana Murthy^c

Frontiers in Heat and Mass Transfer, Vol.13, pp. 1-8, 2019, DOI:10.5098/hmt.13.6

Abstract This paper analyzes a hypothesis of the 2−dimensional thermal transport behavior of Newtonian axisymmetric, viscous heating flow in a horizontal pipe. The flow is subjected to an externally applied uniform suction across the pipe wall in the polar direction, a constant magnetic field perpendicular to the wall and a uniform heat source/sink on the surface of the cylinder. The thermal boundary condition is imposed as a uniform heat flux. The Velocity fields are expressed in terms of stream function and the solution is obtained using the homotopy analysis method (HAM). Graphs are designed to analyze More >

Ming Zhao^* , Yang Tian

Frontiers in Heat and Mass Transfer, Vol.13, pp. 1-10, 2019, DOI:10.5098/hmt.13.4

Abstract The field synergy principle and thermal resistance analysis were carried out for the heat transfer enhancement of a chip heat sink. Thermal analysis of the heat dissipation capacity is applied for setting up the gallery on the rib, changing the fan ventilation diameter, and changing the rib height. The results show that the analysis of field synergy principle agrees well with that of the thermal analysis, and setting up a gallery on the rib can improve the heat capacity of the heat sink. Meanwhile, the results also show that decreasing diameter of the ventilation causes More >

B. Orr^a,* , R. Singh^a, T. L. Phan^a , M. Mochizuki^b

Frontiers in Heat and Mass Transfer, Vol.13, pp. 1-6, 2019, DOI:10.5098/hmt.13.1

Abstract One of the problems with cooling an IGBT inverter chip is that its heat generation is not constant. These chips tend to produce heat in pulses which results in high peak chip temperatures. Transient modelling is required to determine the suitability of a heat sink and to ensure the max peak temperature is not exceeded. This paper demonstrates a method of transient thermal analysis using a thermal resistance / capacitor network. A sample heat sink was modelled and then experimentally tested to validate the model. A novel method of modelling phase change materials (PCM) using More >

Ziad Saghir, Cayley Delisle, Christopher Welsford^*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.1, pp. 19-19, 2019, DOI:10.32604/icces.2019.05145

Abstract The enhancement of consumer and industrial electronics has led to an increase in both the power and compactness of the products available. However, with these increases follows a subsequent increase in the thermal losses experienced across, for example, a central processing unit (CPU). As well, the need to dissipate waste thermal energy is compounded by the increased compactness. As the chipsets become smaller, the threads contained therein also reduce in size and as such become more sensitive to temperature gradients which can cause deformation. Although this deformation is miniscule, its continuous repetition can ultimately result… More >

Izyan Syazana Awaludin^{1, 2}, Anuar Ishak^2,*, Ioan Pop³

CMES-Computer Modeling in Engineering & Sciences, Vol.120, No.1, pp. 203-214, 2019, DOI:10.32604/cmes.2019.06594

Abstract The present study considers the magnetohydrodynamic (MHD) stagnation point flow with chemical reaction effect over a permeable stretching/shrinking sheet. The partial differential equations are reduced to a set of ordinary differential equations using a similarity transformation. The transformed equations are then solved numerically by employing the bvp4c function available in the MATLAB software. The numerical results illustrate the effects of several parameters on the skin friction coefficient, local Nusselt number and the local Sherwood number. Dual solutions are obtained for a certain range of parameters. The temporal stability analysis is carried out to determine which More >

Mirmanto^*, I.B. Alit, I.M.A. Sayoga, R. Sutanto, Nurchayati, A. Mulyanto

Frontiers in Heat and Mass Transfer, Vol.10, pp. 1-7, 2018, DOI:10.5098/hmt.10.34

Abstract A comparison study of the use of two different heat removal units was conducted to examine the performance of thermoelectric cooler box. The heat removal units employed were a heat sink fin-fan and a double fan heat pipe. Parameters measured as performance indicators are cooling capacity, temperature differences, and COP. In addition, the effect of electrical power on temperature difference and COP was also investigated. The cooler box size is 285 mm x 245 mm x 200 mm and constructed from styrofoam. The results show that there is no difference of the use of a More >