Empirical Optimization of High Density Plate-Fin Heat Sink for Constant Pumping Power in Low Profile Cooling Application

2005 ◽  
Author(s):  
Kazuaki Yazawa ◽  
Tatsuro Yoshida ◽  
Shinji Nakagawa ◽  
Masaru Ishizuka
Keyword(s):  
Fluid Dynamic ◽  
Dynamic Performance ◽  
High Heat ◽  
Heat Sinks ◽  
High Heat Flux ◽  
Pumping Power ◽  
Low Profile ◽  
Data Points ◽  
Narrow Space ◽  
The Impact

Since the VLSI processors are increasing power in accordance with exponential law, cooling solutions for such as personal computers have been evolving for over a decade. Recent heat sinks are designed with high dense fins and low profile to adapt to a high heat flux source within a slim enclosure. To achieve such compact cooling solution, thin fin and small gap is desirable. In addition, the pumping power is also limited by the allowable narrow space for fans. Thus it is important to minimize the thermal resistance for given pumping power that we define the optimum. Due to the lack of literatures on topic of low profile and high dense fins experiments, an apparatus was specially built to measure the thermal and fluid dynamic performance at the same time. Since such a high dense fin arrangement requires extra space on the sides by manufacturing reasons, the impact of bypass flow needs to be considered. The experiments are carefully carried out and the results are precisely compared with numerical analysis. The numerical model aiming to find the optimum for given pumping power is discussed with extrapolating the data points. This report is concluded with the best configuration of plate fins of low profile heat sinks for a given fan performance.

Characterization and Analysis of Low Profile Plate-Fin Heat Sinks for Advanced Thermal Packaging of Consumer Electronics

2005 ◽  
Author(s):  
K. Yazawa ◽  
T. Yoshida ◽  
S. Nakagawa ◽  
M. Ishizuka
Keyword(s):  
Heat Sink ◽  
Fluid Dynamic ◽  
Consumer Electronics ◽  
Heat Sinks ◽  
Pumping Power ◽  
Cooling Fan ◽  
Vlsi Chip ◽  
Low Profile ◽  
Advanced Packaging ◽  
Better Than

Thermal performance in conjunction with fluid dynamic characterization and analysis on low profile heat sink was carried out. Regardless to the increasing power of VLSI chip, recent advanced packaging for compact and slim enclosure for consumer electronics requires a low profile heat sink with a small space available for cooling fan that limits the power of pumping airflow. Therefore, highly integrated fins for low profile heat sink become important to be characterized and modeled. Such low profile and high fin density heat sink has non-ideal shape for shrouding that has not been modeled yet. Proposed semi-bypass model particularly for the practical application of such heat sink is discussed with experimental results and numerical analysis. The apparatus is designed to measure both thermal and fluid dynamic characteristics at the same time. The results are compared based on tested range and found in good agreement at near optimum design. With utilizing this analytic model, cooling performance is optimized with fin number for given pumping power. To understand the shroud impact, these heat sinks are compared with similar foot print and conventional open fin heat sinks which have been already characterized. In addition, semi-bypass impact is also compared with ideally full shroud case in the model. Interestingly, this semi-bypass design is found slightly better than full shroud heat sinks in terms of the performance for same given pumping power.

Thermohydrodynamic Performance Evaluation of Recharging, Interrupted and Simple Microchannels: A Comparative Study

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Sangram Kumar Samal ◽  
Manoj Kumar Moharana
Keyword(s):  
Heat Transfer ◽  
Aspect Ratio ◽  
Three Dimensional ◽  
High Heat ◽  
Heat Sinks ◽  
High Heat Flux ◽  
Transverse Wall ◽  
Performance Factor ◽  
Channel Aspect Ratio ◽  
Small Channels

Abstract In this study, a three-dimensional numerical investigation on the thermohydrodynamic performance of a recently proposed recharging microchannel (RMC) is carried out. In this design, a straight microchannel is split into more than one smaller length channels (having individual inlet and outlet) placed end to end. This design enhances overall heat transfer and maintains temperature uniformity across the substrate length. The comparison of fluid flow and heat transfer performance of RMC, interrupted microchannel (IMC) and straight microchannel (SMC) with the same hydraulic diameter and substrate length are presented to explore the effect of geometrical configuration on heat transfer enhancement. The parametric variations include the number of channels (n), transverse wall length (Ltw), channel aspect ratio (α), and flow Reynolds number. The results reveal that recharging microchannel shows better thermal performance compared to simple and interrupted microchannel with a maximum performance factor of 1.80. The results also indicate that the performance factor of RMC increases with an increase in the number of small channels, transverse wall length, and channel aspect ratio. The outcome of this study indicates the possible use of recharging microchannel heat sinks for high heat flux removal applications such as electronic cooling.

Effect of Orientation and Draining on Linear Spray Array Thermal Management

2007 ◽  
Author(s):  
Benjamin M. Regner ◽  
Timothy A. Shedd
Keyword(s):  
Heat Transfer ◽  
Fluid Management ◽  
High Heat ◽  
Practical Implementation ◽  
High Heat Flux ◽  
Large Area ◽  
Candidate Solution ◽  
The Impact ◽  
Volumetric Flux ◽  
Uniform Droplet

Spray cooling is a candidate solution for high heat flux cooling applications, and previous work has investigated the impact of parameters of conical sprays such as volumetric flux and Sauter mean diameter on heat transfer performance. However, there has been little work on the impact of drainage and spray orientation on spray performances. In addition, conical sprays are not very practical for large area coverage in compact packages, so this study, presents a novel arrangment that uses linear sprays impinging at an angle such that fluid management and uniform droplet coverage of large areas are both improved. Results for the heat transfer coefficient and CHF of a constrained, practical implementation of a spray array (as opposed to a laboratory-only geometry) are presented for FC-72, FC-40 and HFE-7000.

scholarly journals Computational Study of Heat Transfer inside Different PCMs Enhanced by Al2O3 Nanoparticles in a Copper Heat Sink at High Heat Loads

Nanomaterials ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 284 ◽  
Author(s):  
Nadezhda S. Bondareva ◽  
Nikita S. Gibanov ◽  
Mikhail A. Sheremet
Keyword(s):  
Phase Change ◽  
Phase Change Materials ◽  
Computational Study ◽  
Conjugate Problem ◽  
High Heat ◽  
Solid Particles ◽  
Heat Sinks ◽  
Al2o3 Nanoparticles ◽  
Electronic Elements ◽  
The Impact

The cooling of electronic elements is one of the most important problems in the development of architecture in electronic technology. One promising developing cooling method is heat sinks based on the phase change materials (PCMs) enhanced by nano-sized solid particles. In this paper, the influence of the PCM’s physical properties and the concentration of nanoparticles on heat and mass transfer inside a closed radiator with fins, in the presence of a source of constant volumetric heat generation, is analyzed. The conjugate problem of nano-enhanced phase change materials (NePCMs) melting is considered, taking into account natural convection in the melt under the impact of the external convective cooling. A two-dimensional problem is formulated in the non-primitive variables, such as stream function and vorticity. A single-phase nano-liquid model is employed to describe the transport within NePCMs.

scholarly journals Numerical Study of Double-Layered Microchannel Heat Sinks with Different Cross-Sectional Shapes

Entropy ◽  
2018 ◽  
Vol 21 (1) ◽  
pp. 16 ◽  
Author(s):  
Daxiang Deng ◽  
Guang Pi ◽  
Weixun Zhang ◽  
Peng Wang ◽  
Ting Fu
Keyword(s):  
Pressure Drop ◽  
Thermal Resistance ◽  
Thermal Performance ◽  
Numerical Study ◽  
Heat Sinks ◽  
High Heat Flux ◽  
Pumping Power ◽  
Cross Sectional ◽  
Prime Concern ◽  
Microchannel Heat Sinks

This work numerically studies the thermal and hydraulic performance of double-layered microchannel heat sinks (DL-MCHS) for their application in the cooling of high heat flux microelectronic devices. The superiority of double-layered microchannel heat sinks was assessed by a comparison with a single-layered microchannel heat sink (SL-MCHS) with the same triangular microchannels. Five DL-MCHSs with different cross-sectional shapes—triangular, rectangular, trapezoidal, circular and reentrant Ω-shaped—were explored and compared. The results showed that DL-MCHS decreased wall temperatures and thermal resistance considerably, induced much more uniform wall temperature distribution, and reduced the pressure drop and pumping power in comparison with SL-MCHS. The DL-MCHS with trapezoidal microchannels performed the worst with regard to thermal resistance, pressure drop, and pumping power. The DL-MCHS with rectangular microchannels produced the best overall thermal performance and seemed to be the optimum when thermal performance was the prime concern. Nevertheless, the DL-MCHS with reentrant Ω-shaped microchannels should be selected when pumping power consumption was the most important consideration.

Thermal Design of Microchannel Heat Sinks for Low-Orbit Micro-Satellites

2005 ◽  
Author(s):  
Amaury J. H. Heresztyn ◽  
Nicole C. DeJong Okamoto
Keyword(s):  
Heat Flux ◽  
Fluid Model ◽  
High Heat ◽  
Thermal Design ◽  
Heat Sinks ◽  
High Heat Flux ◽  
Propulsion Systems ◽  
Pressure Drops ◽  
Nuclear Propulsion ◽  
Microchannel Heat Sinks

As reduction in the size of electronics creates demand for smaller, less expensive and faster-to-produce spacecraft, the use of high heat flux electronics or advanced nuclear propulsion systems will increase the stress on the thermal subsystem. This work presents a thermal management solution to this problem using liquid-cooled microchannel heat sinks. First, a simple computer model is used to illustrate the need for an atypical cooling method when high-heat flux electronics are used. Second, a thermal/fluid model of microchannel heat sinks is developed and applied to address the satellite thermal need. The total thermal resistances and pressure drops show excellent comparison with published experimental and analytical results. Finally, the model of the microchannel heat sink is optimized to remove 25 W/cm2 over a footprint of 3.7cm2. The mass flow rate needed was significantly lower (almost 5–10 times lower) when compared to other published results, which means that micro-pumps available on the market will be sufficient. The integration of the microchannel system with the satellite is also discussed.

Numerical Simulation on Molten Metal Collision Behavior Using SPH Method Combined with Fractal Analysis on Morphology of Stacking Pattern

2016 ◽  
Vol 715 ◽  
pp. 203-209
Author(s):  
Masatoshi Futakawa ◽  
Kihei Tsutsui ◽  
Hiroyuki Kogawa ◽  
Takashi Naoe
Keyword(s):  
Proton Beam ◽  
Impact Velocity ◽  
Fractal Analysis ◽  
High Heat ◽  
Proton Accelerator ◽  
Beam Power ◽  
High Heat Flux ◽  
Stacking Pattern ◽  
And Behavior ◽  
The Impact

The developments of the high power proton accelerators become a worldwide interest to provide various applications, where the targets are demanded to efficiently produce secondary beams and to survive intensive MW class proton beam power supplied by the accelerators. Solid metal targets might be melted by very high heat flux that is caused by the intensive proton beam bombardment. In fact, the incident occurred at J-PARC (Japan Proton Accelerator Research Complex), in which the gold solid target was locally melted to explosively jet molten gold. The molten gold jet collided with a structural beryllium flange plate that has a function of vacuum boundary. Some parts of molten gold were splashed and the other stuck on the flange plate. The relationship between the impact velocity and the morphology of the sticking pattern on the plate was quantitatively evaluated by introducing fractal analysis. It was found that the fractal dimension is correlated with the impact velocity and might be a useful factor to indicate the localized impact force and behavior.

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