Optimization of Finned Heat Sinks for Impingement Cooling of Electronic Packages

1998 ◽  
Vol 120 (3) ◽  
pp. 259-266 ◽  
Author(s):  
Y. Kondo ◽  
M. Behnia ◽  
W. Nakayama ◽  
H. Matsushima
Keyword(s):  
Cost Effective ◽  
Heat Sinks ◽  
Design Parameters ◽  
Air Cooling ◽  
Electronic Packages ◽  
Impingement Cooling ◽  
Computational Fluid Dynamics Simulations ◽  
Design Calculations ◽  
Dynamics Simulations ◽  
Fin Thickness

The study of optimization of finned heat sinks for impingement cooling of electronic components was undertaken. The procedure was based on a semiempirical zonal approach to the determination of thermal resistance as well as pressure drop. To test the validity of the model’s predictions, experiments and CFD (computational fluid dynamics) simulations were performed. The results provided support for the approach. The model enables cost-effective design calculations to be performed for the optimization of heat sinks. We performed such calculations to optimize an LSI heat sink in consideration of sixteen design parameters, including fin thickness, fin spacing, fin height, and flow-orifice dimensions. For the particular application considered in our study, the optimum fin thickness was found to be 0.15 mm. The characteristics and limitations of air cooling for such applications were investigated under various conditions.

Optimization of Pin-Fin Heat Sinks for Impingement Cooling of Electronic Packages

2000 ◽  
Vol 122 (3) ◽  
pp. 240-246 ◽  
Author(s):  
Y. Kondo ◽  
H. Matsushima ◽  
T. Komatsu
Keyword(s):  
Cost Effective ◽  
Heat Sinks ◽  
Design Parameters ◽  
Air Cooling ◽  
Electronic Packages ◽  
Electronic Components ◽  
Impingement Cooling ◽  
Zonal Model ◽  
Pin Fin ◽  
Semi Empirical

Optimization of pin-fin heat sinks for impingement cooling of electronic components was studied. The study was based on a semi-empirical zonal model for determining thermal resistance as well as pressure drop. To test the validity of the model’s predictions, experiments and flow visualization were performed. The experimental results validated the model. The model enables cost-effective designs to be calculated in order to optimize pin-fin heat sinks. These calculations took into consideration 16 design parameters including pin diameter, minimum spacing between pins, and fin height. For the particular blower considered in our study, the optimum pin diameter was found being 0.35 mm. And the characteristics and limitations of air-cooling for such applications were investigated under various conditions. [S1043-7398(00)01704-7]

scholarly journals Evaluation of Active Heat Sinks Design under Forced Convection—Effect of Geometric and Boundary Parameters

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2041
Author(s):  
Eva C. Silva ◽  
Álvaro M. Sampaio ◽  
António J. Pontes
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Additive Manufacturing ◽  
Pressure Drop ◽  
Forced Convection ◽  
Thermal Performance ◽  
Heat Sinks ◽  
Trapezoidal Shape ◽  
Computational Fluid Dynamics Simulations ◽  
Dynamics Simulations

This study shows the performance of heat sinks (HS) with different designs under forced convection, varying geometric and boundary parameters, via computational fluid dynamics simulations. Initially, a complete and detailed analysis of the thermal performance of various conventional HS designs was taken. Afterwards, HS designs were modified following some additive manufacturing approaches. The HS performance was compared by measuring their temperatures and pressure drop after 15 s. Smaller diameters/thicknesses and larger fins/pins spacing provided better results. For fins HS, the use of radial fins, with an inverted trapezoidal shape and with larger holes was advantageous. Regarding pins HS, the best option contemplated circular pins in combination with frontal holes in their structure. Additionally, lattice HS, only possible to be produced by additive manufacturing, was also studied. Lower temperatures were obtained with a hexagon unit cell. Lastly, a comparison between the best HS in each category showed a lower thermal resistance for lattice HS. Despite the increase of at least 38% in pressure drop, a consequence of its frontal area, the temperature was 26% and 56% lower when compared to conventional pins and fins HS, respectively, and 9% and 28% lower when compared to the best pins and best fins of this study.

Analysis and Control of Pouring Ladle with Weir for Sloshing and Volume-Moving Vibration in Pouring Cut-Off Process

2017 ◽  
Vol 11 (4) ◽  
pp. 645-656
Author(s):  
Atsushi Ito ◽  
Ryosuke Tasaki ◽  
Makio Suzuki ◽  
Kazuhiko Terashima ◽  
◽  
...  
Keyword(s):  
Molten Metal ◽  
Vibration Suppression ◽  
Flow Behavior ◽  
Design Parameters ◽  
Control Input ◽  
Control Approach ◽  
Body Side ◽  
Computational Fluid Dynamics Simulations ◽  
Dynamics Simulations ◽  
And Control

This paper presents analysis results of molten metal vibration for the pouring ladle of an automatic pouring system and proposes vibration suppression control during backward tilting of the ladle in the pouring cut-off process. The pouring ladle has a weir to avoid contamination of the molten metal. The weir separates the interior of the ladle into a body side and a nozzle side. First, weir effects on flow behavior are analyzed by comparing ladles with and without weirs using computational fluid dynamics simulations. In this analysis, a trapezoidal shaped input is designed as a backward tilting velocity. As a result, molten metal in the ladle with weir shows not only sloshing but also moving-volume vibration at the weir opening area. Secondly, the center points of the tilting motion are each verified by residual vibrations using FFT analysis. The frequencies of vibrating elements are nearly identical; however, analysis results show that the sloshing magnitude varies with changing center point of the tilting motion. In addition, effects of weir position and opening area on peak frequencies are analyzed. Each condition affects a frequency of moving-volume vibration. In addition, weir position changes sloshing frequencies at both body side and nozzle side of the pouring ladle. Finally, the suppression control input for each vibration is designed using the Input Shaping control approach. Design parameters for the control input were identified from residual vibrations, and assumed to be a second-order lag system. The effectiveness of the proposed suppression control input is verified by comparison with the non-controlled case.

Least-Volume Optimization of Finned Heat Sinks for Burn-in Air-Cooling Solutions

2003 ◽  
Author(s):  
Zhaojuan He ◽  
Patrick E. Phelan
Keyword(s):  
Heat Sink ◽  
Heat Dissipation ◽  
Past Research ◽  
Heat Sinks ◽  
Air Cooling ◽  
Electronic Packages ◽  
Pin Fin ◽  
Heat Spreaders ◽  
Forced Air ◽  
Innovative Techniques

With the development and increasing use of high-density components with their high power dissipation needs, electronic packages have required the investigation of innovative techniques for the efficient dissipation of heat. One prevalent method is the use of forced convection heat spreaders, called heat sinks, which are also widely used in Burn-In (BI) ovens. There are some contradictions remaining in recent research on modeling and Nusselt number correlations of heat sinks in forced air convection. This paper begins by reviewing past research for different finned heat sink geometries with and without bypass flow over the heat sinks. A new method called Least Volume Optimization is then proposed to analyze the thermal performance of finned heat sinks for BI air-cooling solutions. The analysis shows that the volumetric heat dissipation of a parallel plate fin heat sink is higher than that of a pin fin heat sink, based on an optimal fin geometry.

Parametrization of the fire-smoke exhaust system for a large and high-rise atrium in Shanghai through salt-bath experiment

2016 ◽  
Vol 26 (2) ◽  
pp. 272-291 ◽  
Author(s):  
Jian Wang ◽  
Juan Gui ◽  
Jun Gao ◽  
Xueli Hu
Keyword(s):  
Exhaust System ◽  
Salt Bath ◽  
Design Parameters ◽  
Smoke Movement ◽  
High Rise ◽  
Filling Time ◽  
Fire Smoke ◽  
Computational Fluid Dynamics Simulations ◽  
Dynamics Simulations ◽  
Smoke Filling

Present specifications in Building Codes in China lack design parameters for smoke exhaust for large and high-rise atrium in buildings. An investigation of natural smoke filling and parametrization of fire-smoke exhaust in an atrium building in Shanghai was conducted based on salt-bath experiment, due to dynamic analogy between thermal smoke movement in air and brine dispersion in water. To obtain a small, scaled-down version of an atrium with a high polyfoam fire up to 1 MW, the brine-bath experiment was conducted with calcium chloride for small strength fire in small-space rooms, to demonstrate the natural smoke filling within the atrium. The interface height and filling time derived was highly comparable to those obtained by empirical equations. The results of computational fluid dynamics simulations agreed well with the salt-bath experiments. The evacuation time was also calculated with a dimensionless interface height of 0.2 to determine whether there was sufficient time for occupants to escape. The smoke filling process under mechanical smoke exhaust was also investigated by experiments, to parametrize the fire smoke exhaust system in the atrium. The optimal smoke exhaust level, natural and mechanical make-up level were determined and were recommended as the design parameters for the construction of atrium in buildings.

A Paramedic Treatment for Modeling Explicitly Solvated Chemical Reaction Mechanisms

2018 ◽  
Author(s):  
Yasemin Basdogan ◽  
John Keith
Keyword(s):  
Reaction Mechanism ◽  
Chemical Reaction ◽  
Reaction Mechanisms ◽  
Reaction Pathway ◽  
Optimization Procedure ◽  
Cost Effective ◽  
Chemical Reaction Mechanisms ◽  
Solvent Molecules ◽  
Dynamics Simulations ◽  
Mbh Reaction

<div> <div> <div> <p>We report a static quantum chemistry modeling treatment to study how solvent molecules affect chemical reaction mechanisms without dynamics simulations. This modeling scheme uses a global optimization procedure to identify low energy intermediate states with different numbers of explicit solvent molecules and then the growing string method to locate sequential transition states along a reaction pathway. Testing this approach on the acid-catalyzed Morita-Baylis-Hillman (MBH) reaction in methanol, we found a reaction mechanism that is consistent with both recent experiments and computationally intensive dynamics simulations with explicit solvation. In doing so, we explain unphysical pitfalls that obfuscate computational modeling that uses microsolvated reaction intermediates. This new paramedic approach can promisingly capture essential physical chemistry of the complicated and multistep MBH reaction mechanism, and the energy profiles found with this model appear reasonably insensitive to the level of theory used for energy calculations. Thus, it should be a useful and computationally cost-effective approach for modeling solvent mediated reaction mechanisms when dynamics simulations are not possible. </p> </div> </div> </div>

Electrochemical cleaning of soils with different concentrations of oil pollution using a single source of electrical voltage

2020 ◽  
Vol 10 (6) ◽  
pp. 674-680
Author(s):  
Nikolay S. Shulaev ◽  
◽  
Valeriya V. Pryanichnikova ◽  
Ramil R. Kadyrov ◽  
Inna V. Ovsyannikova ◽  
...  
Keyword(s):  
Contaminated Soils ◽  
Oil Pollution ◽  
Cost Effective ◽  
Electrical Energy ◽  
Design Parameters ◽  
Technological Infrastructure ◽  
Chemical Reagents ◽  
Electrode Space ◽  
Soil Excavation ◽  
Interelectrode Resistance

The most essential scientifific and practical task in the area of ecological safety of pipelines operation is the development and improvement of methods of purifification and restoration of oil-contaminated soils. One of the most effificient and cost effective methods is electrochemical purifification, that does not require the use of expensive chemical reagents and soil excavation. However, the consideration of non-uniform contamination of various soil sections is required. The article examines the features of the organization and technological infrastructure for electrochemical purifification of non-uniformly contaminated soils when using a single electrical energy source, a method for calculating the design parameters of the corresponding installation is proposed. Effificient purifification of non-uniformly contaminated soil when using a specifified voltage is possible through the use of different-sized electrodes. For each soil type, the amount of transmitted electric charge required for soil purifification is determined by the concentration of the contaminant. Allocation of cathodes and anodes as parallel batteries and their connection using individual buses is an effective and energy-effificient solution, since an almost-uniform electric fifield is created in an inter-electrode space, thus allowing the reduction of the interelectrode resistance of the medium.

Experimental and Analytical Investigation of Compact Liquid Cooled Heat Sinks

2004 ◽  
Author(s):  
M. Zugic ◽  
J. R. Culham ◽  
P. Teertstra ◽  
Y. Muzychka ◽  
K. Horne ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Experimental Tests ◽  
Reynolds Numbers ◽  
High Heat ◽  
Analytical Investigation ◽  
Boundary Resistance ◽  
Heat Fluxes ◽  
Heat Sinks ◽  
Air Cooling ◽  
Design Tools

Compact, liquid cooled heat sinks are used in applications where high heat fluxes and boundary resistance preclude the use of more traditional air cooling techniques. Four different liquid cooled heat sink designs, whose core geometry is formed by overlapped ribbed plates, are examined. The objective of this analysis is to develop models that can be used as design tools for the prediction of overall heat transfer and pressure drop of heat sinks. Models are validated for Reynolds numbers between 300 and 5000 using experimental tests. The agreement between the experiments and the models ranges from 2.35% to 15.3% RMS.

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