Introduction of a novel electric field-based plate heat sink for heat transfer enhancement of thermal systems

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Nader Nourdanesh ◽  
Faramarz Ranjbar
Keyword(s):  
Heat Transfer ◽  
Electric Field ◽  
Thermal Management ◽  
High Voltage ◽  
Heat Sink ◽  
Heat Fluxes ◽  
Heat Sinks ◽  
Parallel Plates ◽  
Thermal Systems ◽  
Content Type

Purpose The purpose of this study is to use an electric field technique to design novel heat sinks capable of rejecting as much heat as possible in a limited space. Configuration of electrodes in this study can be used for increasing the efficiency of heat sinks. Design/methodology/approach This study investigates a novel electrohydrodynamic (EHD)-based heat sink for thermal management of electronic devices and thermal systems. The significant part of designing an EHD heat sink is the arrangement of the electrodes. A numerical simulation is performed for a heat sink with two parallel plates to determine the optimum dimensional configuration of electrodes. The upper plate of this heat sink is the ground electrode with a constant atmosphere temperature, and the lower plate of it with flush-mounted high-voltage electrodes has uniform heat flux. Findings The results show that heat transfer changes by the size of the vortices and the number of them. These vortices are emerged by the electric field, and the number of them increases with increasing the number of electrodes. The interaction of vortices size and number leads to having the lowest average temperature in the optimum case by two high voltage electrodes with widths of 7.5 mm and a 17.5 mm gap between them. In comparison with the case without the electric field, with increasing the applied voltage to 30 kV, the efficiency of this EHD heat sink increases up to 37%. Originality/value Improvements in electrical equipment make them more compact with higher heat fluxes. Hence, the amount of heat to be dissipated per area increases and needs thermal management to operate at their design temperatures. Therefore, to improve the performance and life span of electronic components and increase their efficiency, it is necessary to design heat sinks to decrease their maximum (peak) temperature.

Thermal Analysis of Miniature Low Profile Heat Sinks With and Without Fins

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
V. Egan ◽  
P. A. Walsh ◽  
E. Walsh ◽  
R. Grimes
Keyword(s):  
Heat Transfer ◽  
Heat Sink ◽  
Volume Flow Rate ◽  
Electronic Devices ◽  
Heat Fluxes ◽  
Heat Sinks ◽  
Superior Performance ◽  
Low Profile ◽  
In Series ◽  
Heat Sink Design

Reliable and efficient cooling solutions for portable electronic devices are now at the forefront of research due to consumer demand for manufacturers to downscale existing technologies. To achieve this, the power consumed has to be dissipated over smaller areas resulting in elevated heat fluxes. With regard to cooling such devices, the most popular choice is to integrate a fan driven heat sink, which for portable electronic devices must have a low profile. This paper presents an experimental investigation into such low profile cooling solutions, which incorporate one of the smallest commercially available fans in series with two different heat sink designs. The first of these is the conventionally used finned heat sink design, which was specifically optimized and custom manufactured in the current study to complement the driving fan. While the second design proposed is a novel “finless” type heat sink suitable for use in low profile applications. Together the driving fan and heat sinks combined were constrained to have a total footprint area of 465 mm2 and a profile height of only 5 mm, making them ideal for use in portable electronics. The objective was to evaluate the performance of the proposed finless heat sink design against a conventional finned heat sink, and this was achieved by means of thermal resistance and overall heat transfer coefficient measurements. It was found that the proposed finless design proved to be the superior cooling solution when operating at low fan speeds, while at the maximum fan speed tested of 8000 rpm both provided similar performance. Particle image velocimetry measurements were used to detail the flow structures within each heat sink and highlighted methods, which could further optimize their performance. Also, these measurements along with corresponding global volume flow rate measurements were used to elucidate the enhanced heat transfer characteristics observed for the finless design. Overall, it is shown that the proposed finless type heat sink can provide superior performance compared with conventional finned designs when used in low profile applications. In addition a number of secondary benefits associated with such a design are highlighted including lower cost, lower mass, lower acoustics, and reduced fouling issues.

Computational fluid dynamics for thermal performance of a water-cooled minichannel heat sink with different chip arrangements

2014 ◽  
Vol 24 (4) ◽  
pp. 797-810 ◽  
Author(s):  
Gongnan Xie ◽  
Shian Li ◽  
Bengt Sunden ◽  
Weihong Zhang
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Thermal Performance ◽  
Heat Sink ◽  
Electronic Devices ◽  
Heat Sinks ◽  
Bottom Surface ◽  
Moderate Pressure ◽  
Content Type

Purpose – With the development of electronic devices, including the desires of integration, miniaturization, high performance and the output power, cooling requirement of chips have been increased gradually. Water-cooled minichannel is an effective cooling technology for cooling of heat sinks. The minichannel flow geometry offers large surface area for heat transfer and a high convective heat transfer coefficient with only a moderate pressure loss. The purpose of this paper is to analyze a minichannel heat sink having the bottom size of 35 mm×35 mm numerically. Two kinds of chip arrangement are investigated: diagonal arrangement and parallel arrangement. Design/methodology/approach – Computational fluid dynamics (CFD) technique is used to investigate the flow and thermal fields in forced convection in a three-dimensional minichannels heat sink with different chip arrangements. The standard k-e turbulence model is applied for the turbulence simulations on the minichannel heat sink. Findings – The results show that the bottom surface of the heat sink with various chip arrangements will have different temperature distribution and thermal resistance. A suitable chip arrangement will achieve a good cooling performance for electronic devices. Research limitations/implications – The fluid is incompressible and the thermophysical properties are constant. Practical implications – New and additional data will be helpful as guidelines in the design of heat sinks to achieve a good thermal performance and a long lifetime in operation. Originality/value – In real engineering situations, chips are always placed in various manners according to design conditions and constraints. In this case the assumption of uniform heat flux is acceptable for the surfaces of the chips rather than for the entire bottom surface of the heat sink.

Experimental Characterization of a Carbon Fiber Composite Material Heat Sink in Boiling Heat Transfer Using FC-72

2006 ◽  
Author(s):  
Venugopal Gandikota ◽  
Harish Chengalvala ◽  
Amy S. Fleischer ◽  
G. F. Jones
Keyword(s):  
Heat Transfer ◽  
Composite Material ◽  
Carbon Fiber ◽  
Thermal Management ◽  
Thermal Performance ◽  
Heat Sink ◽  
Heat Fluxes ◽  
Two Phase ◽  
Operating Temperatures ◽  
Power Densities

The on-going trend towards increasing device performance while shrinking device size often results in escalating power densities and high operating temperatures. High operating temperatures may lead to reduced reliability and induced thermal stresses. Therefore, it is necessary to employ new and innovative thermal management techniques to maintain a suitable junction temperature at high power densities. For this reason, there is interest in a variety of liquid cooling techniques. This study analyzes a composite material heat sink. The heat sink consists of a very large number of small cross-section fins fabricated from carbon pitch fibers and epoxy. These carbon pitch fibers have a high thermal conductivity along the length of the fin. It is expected that the longer length will result in more heat transfer surface area and a more effective heat sink. This experimental study characterizes the thermal performance of the carbon-fiber heat sink in a two-phase closed loop thermosyphon using FC-72 as the operating fluid. The influence of heat load, thermosyphon fill volume, and condenser operating temperature on the overall thermal performance is examined. The results of this experiment provide significant insight into the possible implementation and benefits of carbon fiber heat sink technology in two-phase flow leading to significant improvements in thermal management strategies for advanced electronics. The carbon fiber heat sink yielded heat transfer coefficients in the range of 1300-1500 W/m2 K for heat fluxes in the range up to 3.2 W/cm2. Resistances in the range of 0.20 K/W – 0.23 K/W were achieved for the same heat fluxes. Condenser temperature and fill ratio did not show a significant effect on any of the results.

The Flow and Heat Transfer Characteristic of Curved Channel CPU Water-Cooled Heat Sinks

2013 ◽  
Vol 391 ◽  
pp. 213-216
Author(s):  
Yan Feng Liu ◽  
Xiang Hong Li ◽  
Shi Ping Li
Keyword(s):  
Heat Transfer ◽  
Heat Sink ◽  
Rectangular Channel ◽  
Transfer Characteristic ◽  
Heat Fluxes ◽  
Heat Sinks ◽  
Curved Channel ◽  
Flow And Heat Transfer ◽  
Heat Sink Temperature ◽  
Better Than

This article conducted numerical simulation and experimental study of curved channel laminar flow and heat transfer characteristics with different Reynolds number and different heat fluxes, it also showed the comparison with straight rectangular channel of a same heat transfer area. The results showed that: cooling effect of curved channel heat sink is better than that of straight rectangular channel heat sink, temperature distribution appears to be more uniform as well; The experimental results showed that the curved channel heat sink can effectively satisfy the needs of the CPU cooling.

Additive Manufactured Impinging Coolant, Low Electromagnetic Interference, and Nonmetallic Heat Spreader: Design and Optimization

2020 ◽  
Vol 142 (4) ◽  
Author(s):  
Reece Whitt ◽  
Skyler Hudson ◽  
David Huitink ◽  
Zhao Yuan ◽  
Asif Emon ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Additive Manufacturing ◽  
Thermal Management ◽  
Convective Heat ◽  
High Voltage ◽  
Electromagnetic Interference ◽  
Electronic Device ◽  
Heat Removal ◽  
Heat Sinks ◽  
Transfer Coefficients

Abstract With the increase of electronic device power density, thermal management and reliability are increasingly critical in the design of power electronic systems. First, increased density challenges the capability of conventional heat sinks to adequately dissipate heat. Second, higher frequency switching in high voltage, high current, wide bandgap power modules is creating intensified electromagnetic interference (EMI) challenges, in which metallic heat removal systems will couple and create damaging current ringing. Furthermore, mobile power systems require lightweight heat removal methods that satisfy the heat loads dissipated during operation. In this effort, we introduce an additive manufacturing (AM) pathway to produce custom heat removal systems using nonmetallic materials, which take advantage of impinging fluid heat transfer to enable efficient thermal management. Herein, we leverage the precision of additive manufacturing techniques in the development of three-dimensional optimized flow channels for achieving enhanced effective convective heat transfer coefficients. The experimental performance of convective heat removal due to liquid impingement is compared with conventional heat sinks, with the requirement of simulating the heat transfer needed by a high voltage inverter. The implementation of nonmetallic materials manufacturing is aimed to reduce electromagnetic interference in a low weight and reduced cost package, making it useful for mobile power electronics.

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.

Hydoroil-Based Micro Pin Fin Heat Sink

2006 ◽  
Author(s):  
Ali Kosar ◽  
Chih-Jung Kuo ◽  
Yoav Peles
Keyword(s):  
Heat Sink ◽  
Hydraulic Performance ◽  
Heat Fluxes ◽  
Heat Sinks ◽  
Transfer Coefficients ◽  
Pin Fin ◽  
Nusselt Numbers ◽  
Friction Factors ◽  
Pin Fins ◽  
Micro Pin Fins

An experimental study on thermal-hydraulic performance of de-ionized water over a bank of shrouded NACA 66-021 hydrofoil micro pin fins with wetted perimeter of 1030-μm and chord thickness of 100 μm has been performed. Average heat transfer coefficients have been obtained over effective heat fluxes ranging from 4.0 to 308 W/cm2 and mass velocities from 134 to 6600 kg/m2s. The experimental data is reduced to the Nusselt numbers, Reynolds numbers, total thermal resistances, and friction factors in order to determine the thermal-hydraulic performance of the heat sink. It has been found that prodigious hydrodynamic improvement can be obtained with the hydrofoil-based micro pin fin heat sink compared to the circular pin fin device. Fluid flow over pin fin heat sinks comprised from hydrofoils yielded radically lower thermal resistances than circular pin fins for a similar pressure drop.

Influence of selected factors on parameters of a cooling system with a Peltier module and forced air flow

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Krzysztof Posobkiewicz ◽  
Krzysztof Górecki
Keyword(s):  
Thermal Resistance ◽  
Heat Sink ◽  
Cooling System ◽  
Heat Sinks ◽  
Cooling Power ◽  
Cooling Systems ◽  
Content Type ◽  
Peltier Module ◽  
Peltier Modules ◽  
Forced Air

Purpose The purpose of this study is to investigate the validation of the usefulness of cooling systems containing Peltier modules for cooling power devices based on measurements of the influence of selected factors on the value of thermal resistance of such a cooling system. Design/methodology/approach A cooling system containing a heat-sink, a Peltier module and a fan was built by the authors and the measurements of temperatures and thermal resistance in various supply conditions of the Peltier module and the fan were carried out and discussed. Findings Conclusions from the research carried out answer the question if the use of Peltier modules in active cooling systems provides any benefits comparing with cooling systems containing just passive heat-sinks or conventional active heat-sinks constructed of a heat-sink and a fan. Research limitations/implications The research carried out is the preliminary stage to asses if a compact thermal model of the investigated cooling system can be formulated. Originality/value In the paper, the original results of measurements and calculations of parameters of a cooling system containing a Peltier module and an active heat-sink are presented and discussed. An influence of power dissipated in the components of the cooling system on its efficiency is investigated.

Fluid Flow and Heat Transfer of Liquid Sodium in Small-Scale Heat Sinks With Different Geometries

2021 ◽  
Author(s):  
Mahyar Pourghasemi ◽  
Nima Fathi
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Cross Sections ◽  
Heat Sink ◽  
Volume Ratio ◽  
Heat Sinks ◽  
Liquid Sodium ◽  
Small Scale ◽  
Nusselt Numbers ◽  
The Difference

Abstract 3-D numerical simulations are performed to investigate liquid sodium (Na) flow and the heat transfer within miniature heat sinks with different geometries and hydraulic diameters of less than 5 mm. Two different straight small-scale heat sinks with rectangular and triangular cross-sections are studied in the laminar flow with the Reynolds number up to 1900. The local and average Nusselt numbers are obtained and compared against eachother. At the same surface area to volume ratio, rectangular minichannel heat sink leads to almost 280% higher convective heat transfer rate in comparison with triangular heat sink. It is observed that the difference between thermal efficiencies of rectangular and triangular minichannel heat sinks was independent of flow Reynolds number.

High Heat Flux Boiling Heat Transfer for Laser Diode Arrays

2016 ◽  
Author(s):  
Todd M. Bandhauer ◽  
Taylor A. Bevis
Keyword(s):  
Heat Transfer ◽  
Thermal Management ◽  
Laser Diode ◽  
Boiling Heat Transfer ◽  
Single Phase ◽  
Laser Diodes ◽  
Heat Fluxes ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Laser Diode Arrays

The principle limit for achieving higher brightness of laser diode arrays is thermal management. State of the art laser diodes generate heat at fluxes in excess of 1 kW cm−2 on a plane parallel to the light emitting edge. As the laser diode bars are packed closer together, it becomes increasingly difficult to remove large amounts of heat in the diminishing space between neighboring diode bars. Thermal management of these diode arrays using conduction and natural convection is practically impossible, and, therefore, some form of forced convective cooling must be utilized. Cooling large arrays of laser diodes using single-phase convection heat transfer has been investigated for more than two decades by multiple investigators. Unfortunately, either large fluid temperature increases or very high flow velocities must be utilized to reject heat to a single phase fluid, and the practical threshold for single phase convective cooling of laser diodes appears to have been reached. In contrast, liquid-vapor phase change heat transport can occur with a negligible increase in temperature and, due to a high enthalpy of vaporization, at comparatively low mass flow rates. However, there have been no prior investigations at the conditions required for high brightness edge emitting laser diode arrays: >1 kW cm−2 and >10 kW cm−3. In the current investigation, flow boiling heat transfer at heat fluxes up to 1.1 kW cm−2 was studied in a microchannel heat sink with plurality of very small channels (45 × 200 microns) using R134a as the phase change fluid. The high aspect ratio channels (4.4:1) were manufactured using MEMS fabrication techniques, which yielded a large heat transfer surface area to volume ratio in the vicinity of the laser diode. To characterize the heat transfer performance, a test facility was constructed that enabled testing over a range of fluid saturation temperatures (15°C to 25°C). Due to the very small geometric features, significant heat spreading was observed, necessitating numerical methods to determine the average heat transfer coefficient from test data. This technique is crucial to accurately calculate the heat transfer coefficients for the current investigation, and it is shown that the analytical approach used by many previous investigations requires assumptions that are inadequate for the very small dimensions and heat fluxes observed in the present study. During the tests, the calculated outlet vapor quality exceeded 0.6 and the base heat flux reached a maximum of 1.1 kW cm−2. The resulting experimental heat transfer coefficients are found to be as large a 58.1 kW m−2 K−1 with an average uncertainty of ±11.1%, which includes uncertainty from all measured and calculated values, required assumptions, and geometric discretization error from meshing.

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