Design and Simulation of Locally Enhanced Microchannel Heat Sink for Diode Partially Pumped Slab Laser

Author(s):  
Zhanfeng Guo ◽  
Yunna Sun ◽  
Yan Wang ◽  
Guangyuan Wang ◽  
Xutong Song ◽  
...  

With the power level of diode-pumped solid-state laser (DPSSL) rising continuously, its thermal effect has become the main problem limiting the laser performance. In this paper, based on the heat distribution of diode partially end-pumped slab(Innoslab) laser, a shunt rectangular microchannel heat sink with locally enhanced heat dissipation is designed. Firstly, multi-stage parallel short channels are designed in the heat concentration area to enhance the solid-liquid heat exchange in this area, and the effects of structure and working conditions on its heat dissipation performance are investigated. Secondly, the copper layer is introduced into the end face of the low thermal conductivity crystal to form a high thermal conductivity path, which alleviates the heat accumulation inside the crystal. Compared with the traditional liquid-cooled plate system, the maximum temperature of the laser crystal is reduced from 169.62℃ to 118.18℃, the pressure drop is reduced by 66.75%, and the total mass of the system is reduced to 4.87% of the original system, which effectively improves the practical performance of the device.

2016 ◽  
Vol 78 (10-2) ◽  
Author(s):  
Nik Ahmad Faiz Nik Mazlam ◽  
Normah Mohd-Ghazali ◽  
Thierry Mare ◽  
Patrice Estelle ◽  
Salma Halelfadl

The microchannel heat sink (MCHS) has been established as an effective heat removal system in electronic chip packaging. With increasing power demand, research has advanced beyond the conventional coolants of air and water towards nanofluids with their enhanced heat transfer capabilities. This research had been carried out on the optimization of the thermal and hydrodynamic performance of a rectangular microchannel heat sink (MCHS) cooled with carbon nanotube (CNT) nanofluid, a coolant that has recently been discovered with improved thermal conductivity. Unlike the common nanofluids with spherical particles, nanotubes generally come in cylindrical structure characterized with different aspect ratios. A volume concentration of 0.1% of the CNT nanofluid is used here; the nanotubes have an average diameter and length of 9.2 nm and 1.5 mm respectively. The nanofluid has a density of 1800 kg/m3 with carbon purity 90% by weight having lignin as the surfactant. The approach used for the optimization process is based on the thermal resistance model and it is analyzed by using the non-dominated sorting multi-objective genetic algorithm. Optimized outcomes include the channel aspect ratio and the channel wall ratio at the optimal values of thermal resistance and pumping power. The optimized results show that, at high operating temperature of 40°C the use of CNT nanofluid reduces the total thermal resistance by 3% compared to at 20°C and consequently improve the thermal performance of the fluid. In terms of the hydrodynamic performance, the pumping power is also being reduced significantly by 35% at 40°C compared to the lower operating temperature.  


2021 ◽  
Vol 1163 ◽  
pp. 73-88
Author(s):  
Md Tanbir Sarowar

Microchannel heat sink plays a vital role in removing a considerable amount of heat flux from a small surface area from different electronic devices. In recent times, the rapid development of electronic devices requires the improvement of these heat sinks to a greater extent. In this aspect, the selection of appropriate substrate materials of the heat sinks is of vital importance. In this paper, three boron-based ultra-high temperature ceramic materials (ZrB2, TiB2, and HfB2) are compared as a substrate material for the microchannel heat sink using a numerical approach. The fluid flow and heat transfer are analyzed using the finite volume method. The results showed that the maximum temperature of the heat source didn’t exceed 355K at 3.6MWm-2 for any material. The results also indicated HfB2 and TiB2 to be more useful as a substrate material than ZrB2. By applying 3.6 MWm-2 heat flux at the source, the maximum obtained surface heat transfer coefficient was 175.2 KWm-2K-1 in a heat sink having substrate material HfB2.


2021 ◽  
Author(s):  
Andisheh Tavakoli ◽  
Kambiz Vafai

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%.


2021 ◽  
pp. 2140015
Author(s):  
Min Miao ◽  
Hao Zhang ◽  
Hejie Yu ◽  
Lili Cao

With the increasing flourishing of miniaturized, multifunctional, and heterogeneously integrated system in package (SiP), heating problem is becoming more and more serious. In this paper, to meet the heat dissipation needs of the chips thus assembled and to achieve effective thermal management, linear, serpent and spiral shaped microchannel heat sinks were designed and fabricated into copper substrate by electrical discharge machining (EDM) and precision machining technology, acting both as the cooler and mounting base for passive and active SiP interposers. A test platform was set up to characterize the heat dissipation performance of the copper-based microchannel heat sink. The experimental and simulation results show that heat dissipation rate increases with the increasing heat flux density in the range 5–30 W/cm2 for the three microchannel designs, and the peak temperature can all be kept below 340 K (67[Formula: see text]C) even for the highest heat flux. The three designs are compared from the perspective of peak temperature, temperature distribution uniformity and pressure drop. In all, the solution proposed hereby provides a new and optimal option for in-situ cooling for densely integrated electronic hardware.


2012 ◽  
Vol 134 (10) ◽  
Author(s):  
Y. J. Lee ◽  
P. S. Lee ◽  
S. K. Chou

Sectional oblique fins are employed, in contrast to continuous fins in order to modulate the flow in microchannel heat sinks. The breakage of a continuous fin into oblique sections leads to the reinitialization of the thermal boundary layer at the leading edge of each oblique fin, effectively reducing the boundary layer thickness. This regeneration of entrance effects causes the flow to always be in a developing state, thus resulting in better heat transfer. In addition, the presence of smaller oblique channels diverts a small fraction of the flow into adjacent main channels. The secondary flows created improve fluid mixing, which serves to further enhance heat transfer. Both numerical simulations and experimental investigations of copper-based oblique finned microchannel heat sinks demonstrated that a highly augmented and uniform heat transfer performance, relative to the conventional microchannel, is achievable with such a passive technique. The average Nusselt number, Nuave, for the copper microchannel heat sink which uses water as the working fluid can increase as much as 103%, from 11.3 to 22.9. Besides, the augmented convective heat transfer leads to a reduction in maximum temperature rise by 12.6 °C. The associated pressure drop penalty is much smaller than the achieved heat transfer enhancement, rendering it as an effective heat transfer enhancement scheme for a single-phase microchannel heat sink.


Author(s):  
DEEWAKAR SHARMA ◽  
PARBAR PRATHAM SINGH ◽  
HARRY GARG

With increasing demand for higher computational speed and emerging micro-systems, thermal management poses serious challenge for efficient cooling. Among these liquid cooling using microchannels has gained significant attention and has been extended to its double layer configuration which eliminates the drawback of significant temperature variations in single layer system. The double layer configuration has been primarily analyzed for rectangular ducts. In this study the performance of trapezoidal shape double layer microchannel heat sink is investigated and compared to rectangular double layer heat sink of same flow area. Four different possible configurations are analyzed and comparative study among respective counter and parallel configuration is performed followed by comparison among each configuration. The performance is evaluated on the basis of maximum temperature attained at the heated surface as well as minimum temperature variations. Finally the best performing configuration is compared with double layer rectangular heat sink. Analysis shows that among various trapezoidal configurations, the one with larger side face to face is most suitable. Further comparative study with rectangular system shows that performance of trapezoidal double layer heat sink is superior in both aspects, i.e. minimum thermal resistance as well as minimum temperature variations.


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