Heat transfer enhancement of circular and square LED geometry

Hatami

2021

Sci Rep

In current paper, a finned micro-channel is designed for the cooling application in Light Emitting Diode (LED), numerically using Galerkin weighted residual Finite Element Method (GFEM). Selected materials for LED-chip is GaN, Die from Si, Die-attach is made by Au-20Sn, substrate is copper and heat sink material is considered to be Al. To make a convection heat transfer for cooling process, Al2O3-water nanofluid is used as the cooling fluid flow through the micro-channel and tried to maximize the heat transfer efficiency by optimized geometry. For this aim, there geometry variables from the microchannel were selected and minimum possible geometry cases (11 cases) were proposed by Central composite design (CCD) and variables were optimized by the Response Surface Method (RSM). As a main result, parameter B, i.e. fin length had the most effect on the Nusselt number and Al2O3 nanoparticles with φ = 0.05 stated greatest heat transfer value. Also, different designs of fins arrangements, caused up to 6.5% increase in the nanofluid temperature which enhanced the LED cooling process.

Section: Introductionmentioning

confidence: 99%

Optimization of fins arrangements for the square light emitting diode (LED) cooling through nanofluid-filled microchannel

Hatami

2021

Sci Rep

“…Without PCM : is the structure ameliorated in our previous work Ben Salah and Ben Hamida (2018) Where an increasing of the number of the fin was prosed and it shows a good result for improving the natural convection. As it showed in Figure 4 the same dimensions of base and length of fins was conserved.…”

Section: Resultsmentioning

confidence: 88%

“… The initial structure of our LED heat sink was presented in Figure 1 and it was studied by Ha and Graham (2012) 20 × 20 × 2 mm of the Aluminum base attached to four parallel plate fins having 1.5 mm of thickness and separated by three cavities with 4 mm width. Without PCM : is the structure ameliorated in our previous work Ben Salah and Ben Hamida (2018) Where an increasing of the number of the fin was prosed and it shows a good result for improving the natural convection. As it showed in Figure 4 the same dimensions of base and length of fins was conserved.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Alternate PCM with air cavities in LED heat sink for transient thermal management

Salah

2019

HFF

Self Cite

Purpose The purpose of this paper is to optimize the configuration of a heat sink with phase change material for improving the cooling performance of light emitting diodes (LED). Design/methodology/approach A numerical three-dimensional time-dependent model is developed with COMSOL Multiphysics to simulate the phase change material melting process during both the charging and discharging period. Findings The model is validated with previously published works. It found a good agreement. The difference between filled cavities with phase change materials (PCM) and alternate cavities air-PCM is discussed. The last-mentioned showed a good ability for reducing the junction temperature during the melting time. Three cases of this configuration having the same total volume of PCM but a different number of cavities are compared. The case of ten fins with five PCM cavities is preferred because it permit a reduction of 21 per cent of the junction temperature with an enhancement ratio of 2:4. The performance of this case under different power input is verified. Originality/value The use of alternate air-PCM cavities of the heat sink. The use of PCM in LED to delay the peak temperature in the case of thermal shock (for example, damage of fan) An amount of energy is stored in the LED and it is evacuated to the ambient of the accommodation by the cycle of charging and discharging established (1,765 Joule stored and released each 13 min with 1 LED chip of 5 W).

“…Heat transfer performance is a very important topic due to it being present in different engineering domains like plasma manufacture, 1‐12 the improvement of thermal system performance such as solar collectors, 13 condensing and evaporating systems, 14 bubble absorber system, 15‐18 LED lamps, 19,20 heat exchanger, 21‐23 nano–encapsulated phase change materials (NEPCMs), 24‐27 and geothermal and nuclear energies. Currently, due to technological development the cooling of microelectronics devices has become a crucial topic, which attracts the interest of researchers.…”

Section: Introductionmentioning

confidence: 99%

Free convection and thermal radiation of a nanofluid inside an inclined L‐shaped microelectronic module under the Lorentz forces' impact

Massoudi

2020

Heat Trans

Self Cite

This study aims to study numerically the free convection and thermal radiation of an Ag‐water nanofluid inside an L‐shaped inclined microelectronic module under inclined Lorentz forces and uniform heat generation/absorption effects. The study is established using the software COMSOL Multiphysics based on the finite element method. The main results obtained show that convection heat flow enhances by increasing the Rayleigh number, radiation parameter and nanoparticles shape factor, however, it reduces with increasing the Hartmann number and the aspect ratio. In addition, the presence of uniform heat absorption improves the convection heat flow, by contrast, the presence of uniform heat generation damages this. Besides this, the Lorentz forces' directional impact on the convection heat flow is linked to module inclination. The average Nusselt reaches a maximum for module inclination γ = 45 °.