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.

On the Characterisation of Finned and Finless Heat Sinks for Portable Electronics

2007 ◽  
Author(s):  
V. Egan ◽  
P. Walsh ◽  
E. Walsh ◽  
R. Grimes
Keyword(s):  
Thermal Resistance ◽  
Heat Sink ◽  
Electronic Devices ◽  
Heat Fluxes ◽  
Heat Sinks ◽  
Axial Fan ◽  
Maximum Heat ◽  
Maximum Heat Transfer ◽  
Low Profile ◽  
Profile Height

Reliable and efficient cooling solutions for portable electronic devices are now at the forefront of research due to consumer demand for manufacturers to downscale their existing technologies. The power required for these technologies now has to be dissipated over smaller areas resulting in elevated heat fluxes. The most popular choice among engineers in terms of cooling solutions is to integrate a fan with a heat sink and for portable electronic devices this involves the use of a low profile solution. In this paper an experimental investigation on the thermal performance of a finned and finless heat sink integrated with an axial fan, for the purpose of cooling a microchip, is presented. The objective is to characterise the performance of each heat sink in terms of thermal resistance and to develop an understanding of the flow structures in such systems. One of the smallest commercially available fans is used in conjunction with each heat sink giving a total footprint area of 465m2 and profile height of 5mm. Thermal resistances are measured over a range of fan speeds and detailed velocity measurements were taken of the flow within the heat sinks using Particle Image Velocimetry (PIV). The thermal analysis results indicate that the thermal resistance of the system is of order 30 deg C/W for both heat sinks. However, the finless heat sink resulted in slightly lower values over a range of intermediate fan speeds. Hence, indicating that the maximum heat transfer density, for a range of fan speeds, can be achieved with a finless heat sink. The results also define the limiting heat fluxes that can be dissipated in low profile miniature applications.

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.

Performance Comparison of Microchannel Heat Sink Using Boron-Based Ceramic Materials

2021 ◽  
Vol 1163 ◽  
pp. 73-88
Author(s):  
Md Tanbir Sarowar
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Heat Sink ◽  
Electronic Devices ◽  
Ceramic Materials ◽  
Substrate Material ◽  
Heat Sinks ◽  
Maximum Temperature ◽  
Microchannel Heat Sink ◽  
Small Surface

Microchannel heat sink plays a vital role in removing a considerable amount of heat flux from a small surface area from different electronic devices. In recent times, the rapid development of electronic devices requires the improvement of these heat sinks to a greater extent. In this aspect, the selection of appropriate substrate materials of the heat sinks is of vital importance. In this paper, three boron-based ultra-high temperature ceramic materials (ZrB2, TiB2, and HfB2) are compared as a substrate material for the microchannel heat sink using a numerical approach. The fluid flow and heat transfer are analyzed using the finite volume method. The results showed that the maximum temperature of the heat source didn’t exceed 355K at 3.6MWm-2 for any material. The results also indicated HfB2 and TiB2 to be more useful as a substrate material than ZrB2. By applying 3.6 MWm-2 heat flux at the source, the maximum obtained surface heat transfer coefficient was 175.2 KWm-2K-1 in a heat sink having substrate material HfB2.

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.

The Development of an Integrated Fan and Heat Sink Solution for Thermal Management in Low Profile Applications

2006 ◽  
Author(s):  
Ed Walsh ◽  
Ronan Grimes
Keyword(s):  
Heat Flux ◽  
Thermal Management ◽  
Heat Sink ◽  
Heat Sinks ◽  
Portable Electronics ◽  
Low Profile ◽  
Convection Cooling ◽  
New Methodologies ◽  
Heat Sink Design ◽  
Management Issues

The increasing heat flux densities from portable electronics are leading to new methodologies being implemented to provide thermal management within such devices. Many technologies are under development to transport heat within electronic equipment to allow it to be transported into the surroundings via conduction, natural convection and radiation. Few have considered the approach of implementing a forced convection cooling solution in such devices. This work addresses the potential of a low profile integrated fan and heat sink solution to electronics thermal management issues of the future, particularly focusing upon possible solutions in low profile portable electronics. We investigate two heat sink designs with mini channel features, applicable to low profile applications. The thermal performance of the heat sinks is seen to differ by approximately 40% and highlights the importance of efficient heat sink design at this scale.

scholarly journals Experimental analysis of effect of base with different inner geometries filled nano PCM for the thermal performance of the plate fin heat sink

2021 ◽  
pp. 243-243
Author(s):  
Periyannan Lakshmanan ◽  
Saravanan Periyasamy ◽  
Mohan Raman
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Reynolds Number ◽  
Phase Shift ◽  
Experimental Research ◽  
Thermal Performance ◽  
Heat Sink ◽  
Electronic Devices ◽  
Base Plate ◽  
Heat Sinks

Experimental research demonstrates the performance of electronic devices on plate fin heat sinks in order to guarantee that operating temperatures are kept as low as possible for reliability. Paraffin wax (PCM) is a substance that is used to store energy and the aluminum plate fin cavity base is chosen as a Thermal Conductivity Enhancer (TCEs). The effects of PCM material (Phase shift material), cavity form base (Rectangular, Triangular, Concave and Convex) with PCM, Reynolds number (Re= 4000-20000) on heat transfer effectiveness of plate fin heat sinks were experimentally explored in this research. The thermal performance of concave base plate fin heat sink with PCM is increased up to 7.8% compared to other cavity base heat sinks.

Forced Convection Air Cooling of Simulated Low Profile Electronic Components: Part 2—Heat Sink Effects

1991 ◽  
Vol 113 (1) ◽  
pp. 27-32 ◽  
Author(s):  
G. L. Lehmann ◽  
J. Pembroke
Keyword(s):  
Heat Transfer ◽  
Forced Convection ◽  
Flow Rate ◽  
Heat Sink ◽  
Heat Sinks ◽  
Air Cooling ◽  
Channel Spacing ◽  
Heat Transfer Behavior ◽  
Low Profile ◽  
Transfer Behavior

Forced convection air cooling of an array of low profile, card-mounted components has been investigated. A simulated array is attached to one wall of a low aspect ratio duct. This is the second half of a two-part study. In this second part the presence of a longitudinally finned heat sink is considered. The heat sink is a thermally passive “flow disturbance”. Laboratory measurements of the heat transfer rates downstream of the heat sink are reported and compared with the measured values which occur when no heat sinks are present. Data are presented for three heat sink geometries subject to variations in channel spacing and flow rate. In the flow range considered laminar, transitional and turbulent heat transfer behavior has been observed. The presence of a heat sink appears to “trip” the start of transition at lower Reynolds numbers than when no heat sinks are present. A Reynolds number based on component length provides a good correlation of the heat transfer behavior due to variations in flow rate and channel spacing. Heat transfer is most strongly effected by flow rate and position relative to the heat sink. Depending on the flow regime (laminar or turbulent) both relative enhancement and reductions in the component Nusselt number have been observed. The impact of introducing a heat sink is greatest for flow rates corresponding to transitional behavior.

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.

Implementations of Deflectors to Improve the Performance of Heat Sinks

2012 ◽  
Author(s):  
J. P. Ramirez-Vazquez ◽  
A. Hernandez-Guerrero ◽  
J. L. Zuñiga-Cerroblanco ◽  
J. C. Rubio-Arana
Keyword(s):  
Heat Sink ◽  
Numerical Study ◽  
Electronic Devices ◽  
Constant Heat Flux ◽  
Heat Fluxes ◽  
Heat Sinks ◽  
Hydrodynamic Behavior ◽  
Constant Heat ◽  
Pin Fin ◽  
Global Performance

This work presents a numerical study of the thermal and hydrodynamic behavior of a pin-fin heat sink where deflectors are placed along the flow of the coolant air; the effect of the arrangement of the fins and deflectors in the global performance of the heat sink is investigated. The fin geometry analyzed is rectangular, and the arrangement of the fins is inline. The heat sink is placed in a channel in which air flows, and a constant heat flux is applied at the bottom wall of the heat sink with values equivalent to the heat fluxes generated by current electronic devices. Deflectors are placed in the top of the channel in order to drive the air flow into the front and end of the heat sink. The results for the Nusselt number and for the pressure drop along the heat sink are reported. The best dimension of deflectors and pitch for the arrangement based on the thermal and hydraulic performance is attained.

Thermal Performance of Two and Three Dimensional Radial Flow Heat Sinks

2009 ◽  
Author(s):  
Ronan Grimes ◽  
Kieran Hanly ◽  
Edmond Walsh
Keyword(s):  
Heat Transfer ◽  
Heat Sink ◽  
Angular Displacement ◽  
Three Dimensional ◽  
Heat Sinks ◽  
Electronic Systems ◽  
Two Dimensional ◽  
Pressure Drops ◽  
Low Profile ◽  
Fin Spacing

Space and power constraints in many contemporary electronic systems place a greater importance than ever on efficient thermal management solutions. This paper investigates the performance and optimisation of air cooled heat sinks suitable for deployment in compact electronic devices. The heat sinks examined have circular footprint, with air flowing from the centre, radially outwards through radially aligned channels. Heat sink height is examined through experiments which were performed on heat sinks with high and low fins, with two and three dimensional flow and heat transfer phenomena respectively. In both cases the effect of angular fin spacing is investigated to determine optimum fin spacing for a range of heat sink pressure drops. Heat transfer correlations from literature which were originally developed for parallel finned heat sinks are compared with the experimental data. The main findings of the paper are that the performance of the high profile two dimensional heat sink is more sensitive to fin angular displacement than low profile three dimensional heat sinks. The parallel fin correlations from literature were found to predict the performance of the three dimensional heat sinks more accurately than the two dimensional heat sinks.

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