Experimental Study on Natural Convection From Vertical Cylinders With Branched Fins

2013 ◽  
Author(s):  
Kuen Tae Park ◽  
Byeongdong Kang ◽  
Hyun Jung Kim ◽  
Dong-Kwon Kim
Keyword(s):  
Natural Convection ◽  
Heat Dissipation ◽  
Electronic Devices ◽  
Heat Sinks ◽  
Electronic Systems ◽  
Electronic Components ◽  
Cooling Systems ◽  
Cooling Technology ◽  
Vertical Cylinders

Advances in semiconductor technology and trends in slim and light electronic systems have led to a significant increase in heat dissipation density of the electronic devices. Therefore, effective cooling technology is essential for reliable operation of electronic components. Among various cooling systems, natural convection heat sinks have been proven to be appropriate because of their inherent simplicity, reliability, and low long-term cost. The present study is focused on natural convective heat transfer from the cylindrical heat sink. Especially, the branched fins, which are motivated by the branched design of nature shown in trees and lungs, are used. The heating power and surface temperature are measured for various types of branched fins and numbers of fins. The result showed that the branched fin dissipates 20% more heat compared to the normal plate fins. Therefore, heat sinks with branched fins have a potential as a next-generation cooling device.

scholarly journals Cooling Performance of Heat Sinks Used in Electronic Devices

2018 ◽  
Vol 171 ◽  
pp. 02003
Author(s):  
Ibrahim Mjallal ◽  
Hussein Farhat ◽  
Mohammad Hammoud ◽  
Samer Ali ◽  
Ali AL Shaer ◽  
...  
Keyword(s):  
Heat Sink ◽  
Electronic Devices ◽  
Heat Fluxes ◽  
Electronic Cooling ◽  
Heat Sinks ◽  
Passive Cooling ◽  
Short Term ◽  
Cooling Systems ◽  
Thermal Output ◽  
Electrical Devices

Existing passive cooling solutions limit the short-term thermal output of systems, thereby either limiting instantaneous performance or requiring active cooling solutions. As the temperature of the electronic devices increases, their failure rate increases. That’s why electrical devices should be cooled. Conventional electronic cooling systems usually consist of a metal heat sink coupled to a fan. This paper compares the heat distribution on a heat sink relative to different heat fluxes produced by electronic chips. The benefit of adding a fan is also investigated when high levels of heat generation are expected.

A Study on the Control of Residual Stress of Copper Thick-Film Using 2D Nanomaterial

2021 ◽  
Vol 21 (12) ◽  
pp. 5960-5964
Author(s):  
Kwon Jai Lee ◽  
Jee Young Oh ◽  
Kyong Nam Kim
Keyword(s):  
Residual Stress ◽  
Heat Dissipation ◽  
High Efficiency ◽  
Rapid Development ◽  
Electronic Devices ◽  
Copper Film ◽  
Electronics Industry ◽  
Electronic Components ◽  
Graphene Layers ◽  
Electronic Parts

With the rapid development of the electronics industry, high-density electronic devices and component mounting have gained popularity. Because of the heat generated from these devices, efficiency of the electronic parts is significantly lowered and life of various electronic devices is considerably shortened. Therefore, it is essential to efficiently dissipate the heat generated from the device to extend product life and ensure high efficiency of electronic components. This study evaluated how residual stress is impacted by the thickness of the deposited copper film, which is widely used as a heat dissipation material, and the number of graphene layers. The results confirmed that the residual stress decreased with increasing thickness. Moreover, the residual stress changed based on the transfer area of graphene, which had an elastic modulus eight times that of copper, indicating that the residual stress of the deposited copper film can be controlled.

Design of Air and Liquid Cooling Systems for Electronic Components Using Concurrent Simulation and Experiment

Volume 4 ◽  
2004 ◽  
Author(s):  
T. Icoz ◽  
N. Verma ◽  
Y. Jaluria
Keyword(s):  
Heat Transfer ◽  
The Other ◽  
Simple Problem ◽  
Electronic Systems ◽  
Efficient Design ◽  
Electronic Components ◽  
Liquid Cooling ◽  
Cooling Systems ◽  
Simulation And Experiment ◽  
Concurrent Simulation

The design of cooling systems for electronic equipment is getting more involved and challenging due to increase in demand for faster and more reliable electronic systems. Therefore, robust and more efficient design and optimization methodologies are required. Conventional approaches are based on sequential use of numerical simulation and experiment. Thus, they fail to use certain advantages of using both tools concurrently. The present study is aimed at combining simulation and experiment in a concurrent manner such that outputs of each approach drives the other to achieve better engineering design in a more efficient way. In this study, a relatively simple problem involving heat transfer from multiple heat sources, simulating electronic components, located in a horizontal channel was investigated experimentally and numerically. Two experimental setups were fabricated for air and liquid cooling experiments to study the effects of different coolants. De-ionized water was used as the liquid coolant in one case and air in the other. The effects of separation distance and flow conditions on the heat transfer and fluid flow characteristics were investigated in details for both coolants. Cooling capabilities of different cooling arrangements were compared and the results from simulations and experiments were combined to provide quantitative inputs for the design. The domains over which experimental or the numerical approach is superior to the other are determined. Simulations are used to guide the experiments and vice versa. It is found that the proposed optimization methodology can be implemented in the design of cooling systems for electronic components for faster and more efficient convergence. This methodology can also be extended to more complex and practical electronic systems.

Improved Heat Dissipation Capability on Electronic Motor Control Devices

2005 ◽  
Author(s):  
Wei Tong
Keyword(s):  
Heat Transfer ◽  
Motor Control ◽  
Heat Dissipation ◽  
Electronic Devices ◽  
Heat Sinks ◽  
Vortex Generators ◽  
Maximum Temperature ◽  
Complex Heat Transfer ◽  
Pin Fins ◽  
Control Devices

Heat sinks have been widely used in electronic industry to maintain the operation temperatures of electronic devices lower than their allowable values and thus are often critical to the device performance and life. However, it is difficult to design heat sinks to satisfy all design specifications optimally under complex heat transfer phenomena. The present work discloses a new design of heat sinks to improve heat dissipation capability for electric motor control devices. The heat sink contains a plurality of raindrop-shaped pin fins, acting as vortex generators to increase the rate of heat transfer and in turn, to increase the cooling efficiency of the heat sinks. Numerical results have shown that with the new designed heat sinks, the maximum temperature can reduce about 30% over the conventional heat sinks.

scholarly journals Stretchable, dynamic covalent polymers for soft, long-lived bioresorbable electronic stimulators designed to facilitate neuromuscular regeneration

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Yeon Sik Choi ◽  
Yuan-Yu Hsueh ◽  
Jahyun Koo ◽  
Quansan Yang ◽  
Raudel Avila ◽  
...  
Keyword(s):  
Electronic Devices ◽  
Advanced Materials ◽  
Peripheral Nerve Injuries ◽  
Electronic Components ◽  
Elastic Substrate ◽  
Design Considerations ◽  
Disease States ◽  
Surgical Extraction ◽  
Chemical Design

AbstractBioresorbable electronic stimulators are of rapidly growing interest as unusual therapeutic platforms, i.e., bioelectronic medicines, for treating disease states, accelerating wound healing processes and eliminating infections. Here, we present advanced materials that support operation in these systems over clinically relevant timeframes, ultimately bioresorbing harmlessly to benign products without residues, to eliminate the need for surgical extraction. Our findings overcome key challenges of bioresorbable electronic devices by realizing lifetimes that match clinical needs. The devices exploit a bioresorbable dynamic covalent polymer that facilitates tight bonding to itself and other surfaces, as a soft, elastic substrate and encapsulation coating for wireless electronic components. We describe the underlying features and chemical design considerations for this polymer, and the biocompatibility of its constituent materials. In devices with optimized, wireless designs, these polymers enable stable, long-lived operation as distal stimulators in a rat model of peripheral nerve injuries, thereby demonstrating the potential of programmable long-term electrical stimulation for maintaining muscle receptivity and enhancing functional recovery.

Thermally Conductive Plastics for Enhanced Thermal Management

2015 ◽  
Vol 2015 (1) ◽  
pp. 000530-000535
Author(s):  
Chandrashekar Raman
Keyword(s):  
Thermal Conductivity ◽  
Natural Convection ◽  
Thermal Management ◽  
Electronic Devices ◽  
Heat Sinks ◽  
Significant Challenge ◽  
Design Engineers ◽  
Thermally Conductive ◽  
New Material ◽  
Conductive Plastics

Electronic devices continue to shrink while continuing to offer increasing functionality. This trend poses a significant challenge to design engineers who need to adequately address the increasing thermal management requirements of these devices on a shrinking footprint. Thermally conductive plastics have been gaining attention as an innovative new material option to address this challenge. While plastics are typically poor conductors of heat, it is possible to increase the thermal conductivity with the use of certain additives. Unique ceramic additives like boron nitride offer the added advantage of enabling thermally conductive plastic formulations that are also electrically insulating. The replacement of aluminum heat sinks in free (natural) convection environments with thermally conductive plastics is discussed in this paper. The results show it may indeed be possible to replace aluminum with thermally conductive plastic heat sinks in convection limited environments, and if judicious redesign of the plastic heat sink is incorporated, an improved thermal management solution can be realized. Additionally, the benefits of enhancing existing plastic housings to enable an improved thermal management solution are discussed. The results also show that modest enhancements to the thermal conductivity of existing plastic housings can yield significant improvements to the overall thermal management solution as well.

Effect of Synthetic Jets Over Natural Convection Heat Sinks

2008 ◽  
Author(s):  
Mehmet Arik ◽  
Yogen Utturkar ◽  
Murat Ozmusul
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Heat Sink ◽  
Heat Dissipation ◽  
Synthetic Jet ◽  
Synthetic Jets ◽  
Operating Conditions ◽  
Heat Sinks ◽  
Junction Temperature ◽  
Allowable Limit

In moderate power electronics applications, the most preferred way of thermal management is natural convection to air with or without heat sinks. Though the use of heat sinks is fairly adequate for modest heat dissipation needs, it suffers from some serious performance limitations. Firstly, a large volume of the heat sink is required to keep the junction temperature at an allowable limit. This need arises because of the low convective film coefficients due to close spacing. In the present computational and experimental study, we propose a synthetic jet embedded heat sink to enhance the performance levels beyond two times within the same volume of a regular passive heat sink. Synthetic jets are meso-scale devices producing high velocity periodic jet streams at high velocities. As a result, by carefully positioning of these jets in the thermal real estate, the heat transfer over the surfaces can be dramatically augmented. This increase in the heat transfer rate is able to compensate for the loss of fin area happening due to the embedding of the jet within the heat sink volume, thus causing an overall increase in the heat dissipation. Heat transfer enhancements of 2.2 times over baseline natural convection cooled heat sinks are measured. Thermal resistances are compared for a range of jet operating conditions and found to be less than 0.9 K/W. Local temperatures obtained from experimental and computational agreed within ± 5%.

Computations for a Three-by-Three Array of Protrusions Cooled by Liquid Immersion: Effect of Substrate Thermal Conductivity

1995 ◽  
Vol 117 (4) ◽  
pp. 294-300 ◽  
Author(s):  
D. Mukutmoni ◽  
Y. K. Joshi ◽  
M. D. Kelleher
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Fluid Flow ◽  
Natural Convection ◽  
Computational Study ◽  
Fluid Velocity ◽  
Heat Sinks ◽  
Electronic Components ◽  
Liquid Immersion ◽  
Fluid Velocity Field

A computational study of natural convection in an enclosure as applied to applications in cooling of electronic components is reported. The investigation is for a configuration consisting of a three by three array of heated protrusions placed on a vertical substrate. The vertical sidewalls are all insulated, and the top and bottom walls serve as isothermal heat sinks. A thin layer at the back of each protrusion is the heat source, where heat is generated uniformly and volumetrically. The coolant is the flourinert liquid FC75. The code was first validated with experimental results reported earlier on the same configuration. The effect of the substrate conductivity, κs on the heat transfer and fluid flow was then studied for power levels of 0.1 and 0.7 Watts per protrusion. The computations indicate that the effect of increasing κs is dramatic. The protrusion temperatures which were found to be nominally steady, were substantially reduced. The percentage of generated power that is directly conducted to the substrate increased with an increase in κs. The fluid velocity field, which was unsteady, was not significantly affected by changes in κs.

Enhanced Heat Transfer in Radial Heat Sinks for LED Lamps

2018 ◽  
Author(s):  
Fernando Cano-Banda ◽  
Ana Gallardo-Gutierrez ◽  
Jesus Garcia-Gonzalez ◽  
Abel Hernandez-Guerrero ◽  
Luis Luviano-Ortiz
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Heat Sink ◽  
Heat Dissipation ◽  
Heat Sinks ◽  
Output Analysis ◽  
Maximum Heat ◽  
Maximum Heat Transfer ◽  
Longitudinal Orientation ◽  
Radial Heat

A radial design of a passive heat sink for cooling LED illumination devices is analyzed numerically in order to identify the geometric shape that promotes better heat dissipation rates. Natural convection with the surrounding is considered during the operation of the heat sink. Due to the fact that natural convection is the main mechanism of heat transfer, the shape of the heat sink has a high influence in the heat dissipated. An analysis of the influence of different parameters of a heat sink is conducted in the presented study. The radial heat sink under analysis consists in a flat disc with rectangular fins on it, and the fins are distributed with a radial longitudinal orientation in a circular row arrangement. The number of rows can vary but there is a constant relation of two times the number of fins between the number of fins in an inner row and the next outer row. In order to find a correct configuration to improve the dissipation of heat, parameters like the number of fins, the length of the fins and the separation between fins are studied. The average Nusselt number and thermal resistance for each geometric configuration are compared. The output analysis provides the best shape for a maximum heat transfer.

scholarly journals Effect of Surface Microstructure on the Heat Dissipation Performance of Heat Sinks Used in Electronic Devices

Micromachines ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 265
Author(s):  
Yuxin You ◽  
Beibei Zhang ◽  
Sulian Tao ◽  
Zihui Liang ◽  
Biao Tang ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Thermal Radiation ◽  
Heat Sink ◽  
Heat Dissipation ◽  
Electronic Devices ◽  
High Heat ◽  
Heat Sinks ◽  
High Heat Flux ◽  
Thermal Emissivity ◽  
Effect Of Surface

Heat sinks are widely used in electronic devices with high heat flux. The design and build of microstructures on heat sinks has shown effectiveness in improving heat dissipation efficiency. In this paper, four kinds of treatment methods were used to make different microstructures on heat sink surfaces, and thermal radiation coating also applied onto the heat sink surfaces to improve thermal radiation. The surface roughness, thermal emissivity and heat dissipation performance with and without thermal radiation coating of the heat sinks were studied. The result shows that with an increase of surface roughness, the thermal emissivity can increase up to 2.5 times. With thermal radiation coating on a surface with microstructures, the heat dissipation was further improved because the heat conduction at the coating and heat sink interface was enhanced. Therefore, surface treatment can improve the heat dissipation performance of the heat sink significantly by enhancing the thermal convection, radiation and conduction.

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