Thermal Performance of Metal Foam Heat Sink With Pin Fins for Nonuniform Heat Flux Electronics Cooling

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Yongtong Li ◽  
Liang Gong ◽  
Minghai Xu ◽  
Yogendra Joshi
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Heat Sink ◽  
Heat Transfer Performance ◽  
Metal Foam ◽  
Electronics Cooling ◽  
Flow Distribution ◽  
Junction Temperature ◽  
Transfer Performance ◽  
Pin Fins

Abstract In this paper, a concept of metal foam heat sink with pin fins (MFPF heat sink) is proposed to improve the cooling performance of high-powered electronics with nonuniform heat flux. Numerical simulations are carried out to investigate the thermohydraulic performance of MFPF heat sink, and the metal foam (MF) heat sink and traditional pin fin (PF) heat sink are employed for comparison. The capability of MFPF heat sink in handling nonuniform heat flux is examined under different power levels. It indicates that the MFPF heat sink greatly enhances the heat transfer performance, due to the common effects of the improved flow distribution and enhanced overall effective thermal conductivity (ETC). Results also show that the MFPF heat sink promotes the improvement of the bottom wall temperature uniformity. Porosity has more pronounced effects on heat transfer performance of MFPF heat sink than pore density. A nonuniform distribution heat flux (15–80–15 W/cm2) can be successfully dissipated using the proposed MFPF heat sink with the junction temperature below 95 °C at Re of 500.

An Experimental Study of Two Phase Flow in Impinging Micro Channels

2013 ◽  
Author(s):  
Liang-Han Chien ◽  
Han-Yang Liu ◽  
Wun-Rong Liao
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Flow Rate ◽  
Heat Sink ◽  
Heat Transfer Performance ◽  
Experimental Result ◽  
Working Fluid ◽  
Transfer Performance ◽  
Two Phase ◽  
Micro Channels

A heat sink integrating micro-channels with multiple jets was designed to achieve better heat transfer performance for chip cooling. Dielectric fluid FC-72 was the working fluid. The heat sink contained 11 micro-channels, and each channel was 0.8 mm high, 0.6 mm wide, and 12 mm in length. There were 3 or 5 pores on each micro-channel. The pore diameters were either 0.24 or 0.4 mm, and the pore spacing ranged from 1.5 to 3 mm. In the tests, the saturation temperature of cooling device was set at 30 and 50°C, and the volume flow rate ranged from 9.1 to 73.6 ml/min per channel (total flow rate = 100∼810 ml/min). The experimental result showed that heat transfer performance increased with increasing flow rate for single phase heat transfer. For heat flux between 20 and 100 kW/m2, the wall superheat decreases with increasing flow rate at a fixed heat flux. However, the influence of the flow rate diminished when the channels are in two phase heat transfer regime. Except for the lowest flow rate (9.1 ml/min), the heat transfer performance increased with increasing jet diameter/spacing ratios. The best surface had three nozzles of 0.4 mm diameter in 3.0 mm jet spacing. It had the lowest thermal resistance of 0.0611 K / W in the range of 200 ∼ 240 W heat input.

Enhanced Boiling of FC-72 on Silicon Chips With Micro-Pin-Fins and Submicron-Scale Roughness

2001 ◽  
Vol 124 (2) ◽  
pp. 383-390 ◽  
Author(s):  
H. Honda ◽  
H. Takamastu ◽  
J. J. Wei
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Heat Transfer Performance ◽  
High Heat ◽  
High Heat Flux ◽  
Transfer Performance ◽  
Wall Superheat ◽  
Submicron Scale ◽  
Pin Fins ◽  
Scale Roughness

Experiments were conducted to study the effects of micro-pin-fins and submicron-scale roughness on the boiling heat transfer from a silicon chip immersed in a pool of degassed and gas-dissolved FC-72. Square pin-fins with fin dimensions of 50×50×60μm3 (width×thickness×height) and submicron-scale roughness (RMS roughness of 25 to 32 nm) were fabricated on the surface of square silicon chip 10×10×0.5mm3 by use of microelectronic fabrication techniques. Experiments were conducted at the liquid subcoolings of 0, 3, 25, and 45 K. Both the micro-pin-finned chip and the chip with submicron-scale roughness showed a considerable heat transfer enhancement as compared to a smooth chip in the nucleate boiling region. The chip with submicron-scale roughness showed a higher heat transfer performance than the micro-pin-finned chip in the low-heat-flux region. The micro-pin-finned chip showed a steep increase in the heat flux with increasing wall superheat. This chip showed a higher heat transfer performance than the chip with submicron-scale roughness in the high-heat-flux region. The micro-pin-finned chip with submicron-scale roughness on it showed the highest heat transfer performance in the high-heat-flux region. While the wall superheat at boiling incipience was strongly dependent on the dissolved gas content, it was little affected by the liquid subcooling.

Proposal of a Micro/Mini Cooling Device Using Fins-Installed Porous Media for High Heat Flux Removal Exceeding 1000W/cm2

2009 ◽  
Author(s):  
Kazuhisa Yuki ◽  
Akira Matsui ◽  
Hidetoshi Hashizume ◽  
Koichi Suzuki
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Heat Sink ◽  
Heat Transfer Performance ◽  
High Heat ◽  
Heat Sinks ◽  
High Heat Flux ◽  
Transfer Performance ◽  
Cooling Device ◽  
Fin Thickness

Heat transfer characteristics of micro-sized bronze particle-sintered porous heat sinks and copper minichannel-fins heat sinks are experimentally investigated in order to clarify the feasibility of a newly proposed micro/mini cooling device using fins-installed porous media. Regarding the porous heat sinks, fin effect toward more inside of the porous medium is promoted by sintering the porous heat sink on the heat transfer surface, which results in increasing the heat transfer performance up to 0.8MW/m2K at heat flux of 8.2MW/m2 though there still remains a large pressure loss issue. In addition, the results clarify that the heat exchanging area exists only in the vicinity of the heat transfer surface. As to the minichannel-fins heat sinks, the influence of the channel width and the fin thickness are evaluated in detail. As a result, the minichannel-fins heat sink having the narrower channel width (i.e. scale effect) and lower porosity (i.e. thicker fin thickness with larger heat capacity) achieves higher heat transfer performance up to 0.10MW/m2K at 8.3MW/m2. However, rapid increase of pressure loss, which is occasionally observed in a microchannel due to vapor bubbles choking the narrow channel, still remains as an issue under flow boiling conditions in the minichannel. Finally, heat transfer performance of the fin-installed porous heat sink is numerically predicted by the control volume method. The simulation confirms that the heat transfer coefficient at each wall superheat of 0 and 30 degrees has performance 2.5 times and 2.0 times higher than that of the normal fins, which indicates that this heat sink coupling the micro and mini channels has high potential as efficient cooling method under high heat flux conditions exceeding 10MW/m2.

Convective Heat Transfer Performance of FC-72 in a Pin-Finned Channel

2008 ◽  
Author(s):  
Liang-Han Chien ◽  
S.-Y. Pei ◽  
T.-Y. Wu
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Flow Rate ◽  
Smooth Surface ◽  
Heat Transfer Performance ◽  
Fluid Temperature ◽  
Transfer Performance ◽  
Finned Surface

This study investigates the influence of the heat flux and mass velocity on convective heat transfer performance of FC-72 in a rectangular channel of 20mm in width and 2 mm in height. The heated side has either a smooth surface or a pin-finned surface. The inlet fluid temperature is maintained at 30°C. The total length of the test channel is 113 mm, with a heated length of 25mm. The flow rate varies between 80 and 960 ml/min, and the heat flux sets between 18 and 50 W/cm2. The experimental results show that the controlling variable is heat flux instead of flow rate because of the boiling activities in FC-72. At a fixed flow rate, the pin-finned surface yields up to 20% higher heat transfer coefficient and greater critical heat flux than those of a smooth surface.

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