The Effects of Hybrid Sandblasting Patterns on the Heat Transfer Performance in a Single-Phase Microchannel Heat Sink

2017 ◽  
Author(s):  
Saad K. Oudah ◽  
Ruixian Fang ◽  
Amitav Tikadar ◽  
Karim Egab ◽  
Chen Li ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Sink ◽  
Single Phase ◽  
Heat Transfer Performance ◽  
Bottom Surface ◽  
High Heat Flux ◽  
Microchannel Heat Sink ◽  
Transfer Performance ◽  
Two Phase ◽  
Number Range

An experimental investigation was conducted on a single phase microchannel heat sink, in which the bottom surface of the microchannel was modified with hybrid micro-sandblasting of elliptical patterns (HSEP) and fully sandblasting (FS) to passively enhance the microchannel heat transfer performance. The dimension of the microchannel is measured as 26 mm (L) × 5mm (W) × 0.35 mm (H), which results in a hydraulic diameter of 654 μm. Deionized water was used as the coolant, and the Reynolds number range between 85 to 650 was tested. The experimental results show that fully sandblasting (FS) bottom surface of the microchannel only slightly improved the heat transfer performance. However, the modified surface with HSEP enhanced the heat transfer performance substantially, compared to the benchmark results obtained with the bare surface (BS) microchannel. The pressure drops of the HSEP increased slightly compared to the BS and FS, due to the flow resistance of the microstructures. The proposed surface for enhancement of heat transfer will be useful in many high heat flux engineering applications. In the future, this study will be further extended to two-phase microchannel heat transfer.

Boiling/Evaporation Heat Transfer Augmentation Using Subchannels-Inserted Metal Porous Media

2013 ◽  
Author(s):  
Kazuhisa Yuki ◽  
Masahiro Uemura ◽  
Koichi Suzuki ◽  
Ken-ichi Sunamoto
Keyword(s):  
Heat Transfer ◽  
Porous Medium ◽  
Heat Sink ◽  
Heat Transfer Performance ◽  
Electronic Devices ◽  
High Heat Flux ◽  
Transfer Performance ◽  
Power Electronic ◽  
Copper Particles ◽  
Evaporation Heat

Two-phase flow loop system using a metal porous heat sink is proposed as a cooling system of the future power electronic devices with a heat load exceeding 300W/cm2. In this paper, as the first step, the heat transfer performance of the porous heat sink is evaluated under high heat flux conditions and the applicability and some engineering issues are discussed. The porous medium, which is fabricated by sintering copper particles, has a functional structure with several sub-channels inside it to enhance phase-change as well as discharge of generated vapor outside the porous medium. This porous heat sink is attached onto a heating chip and removes the heat by evaporating cooling liquid passing through the porous medium against the heat flow. Experiments using 30 kW of heating system show that the heat transfer performance of a copper-particles-sintered porous medium with the sub-channels exceeds 800W/cm2 in both high and low subcooling cases and achieves 300W/cm2 at a wall temperature of 150 °C (Tin = 70 °C) and 130 °C (Tin = 70 °C). These results prove that this porous heat sink is applicable enough for cooling 300 W/cm2 class of power electronic devices.

Optimization of Flow and Heat Transfer for a New Double-Layered Microchannel Heat Sink

2019 ◽  
Author(s):  
Huanling Liu ◽  
Bin Zhang
Keyword(s):  
Heat Transfer ◽  
Heat Sink ◽  
Heat Transfer Performance ◽  
Microchannel Heat Sink ◽  
Transfer Performance ◽  
Temperature Uniformity ◽  
Flow And Heat Transfer ◽  
Fluent Simulation ◽  
New Type ◽  
Improved Design

Abstract In this paper, we propose a new type of DL-MCHS to improve the substrate temperature uniformity of the microchannel heat sink, and conduct the optimization of the New DL-MCHS. The heat transfer and friction characteristics of the novel DL-MCHS are studied by numerical simulation. We compare the heat transfer performance the new DL-MCHS with the traditional TDL-MCHS (the DL-MCHS with truncated top channels λ = 0.38). The results prove the effectiveness of the improved design by FLUENT simulation. When the inlet velocity is kept constant and coolant is water, the heat transfer performance of the New DL-MCHS is higher than that of TDL-MCHS leading to an increase of the temperature uniformity. In order to achieving the best overall heat transfer performance, an optimization of New DL-MCHS is performed by GA (genetic algorithm).

Numerical Investigation of Flow Boiling in a Manifold Microchannel Heat Sink With Conjugate Heat Transfer

2019 ◽  
Author(s):  
Zhichuan Sun ◽  
Yang Luo ◽  
Junye Li ◽  
Wei Li ◽  
Jingzhi Zhang ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Numerical Investigation ◽  
Heat Sink ◽  
Conjugate Heat Transfer ◽  
Flow Boiling ◽  
High Heat Flux ◽  
Microchannel Heat Sink ◽  
Two Phase ◽  
Boiling Process ◽  
Manifold Microchannel

Abstract The manifold microchannel heat sink receives an increasing number of attention lately due to its high heat flux dissipation. Numerical investigation of boiling phenomena in manifold microchannel (MMC) heat sinks remains a challenge due to the complexity of fluid route and the limitation of numerical accuracy. In this study, a computational fluid dynamics (CFD) approach including subcooled two-phase flow boiling process and conjugate heat transfer effect is performed using a MMC unit cell model. Different from steady-state single phase prediction in MMC heat sink, this type of modeling allows for the transient simulation for two-phase interface evolution during the boiling process. A validation case is conducted to validate the heat transfer phenomenon among three phases. Besides, this model is used for the assessment of the manifold dimensions in terms of inlet and outlet widths at the mass flux of 1300 kg/m2·s. With different ratios of inlet-to-outlet area, the thermal resistances remain nearly stable.

Two-Phase Heat Transfer Performance of Dielectric Fluid HFE-7100 Within Multiport Microchannel

2008 ◽  
Author(s):  
Lung-Yi Lin ◽  
Yeau-Ren Jeng ◽  
Chi-Chuan Wang
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Single Phase ◽  
Heat Transfer Performance ◽  
Convective Heat Transfer Coefficient ◽  
Dielectric Fluid ◽  
Transfer Performance ◽  
Two Phase ◽  
Two Phase Heat Transfer

This study presents convective single-phase and boiling two-phase heat transfer performance of HFE-7100 coolant within multi-port microchannel heat sinks. The corresponding hydraulic diameters are 450 and 237 μm, respectively. For single-phase results, the presence of inlet/outlet locations inevitably gives rise to considerable increase of total pressure drop of a multi-port microchannel heat sink whereas has virtually no detectable influence on overall heat transfer performance provided that the effect of entrance has been accounted for. The convective boiling heat transfer coefficient for the HFE-7100 coolant shows a tremendous drop when vapor quality is above 0.6. For Dh = 450 μm, it is found that the mass flux effect on the convective heat transfer coefficient is rather small.

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.

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