Design Analysis of a 3-D, Ultra-High Performance, Scalable, Micro Convective Heat Sink With NPCM

2003 ◽  
Author(s):  
Y.-X. Tao ◽  
R. Moreno ◽  
Y. Hao
Keyword(s):  
Phase Change ◽  
Heat Sink ◽  
High Performance ◽  
Phase Change Materials ◽  
High Surface ◽  
Volume Ratio ◽  
Cooling Capacity ◽  
System Level ◽  
Uniform Heat Flux ◽  
Order Of Magnitude

The paper proposes a new design of a scalable, heat sink containing 3-D micro/nano network, utilizing liquid mixed with nano phase change materials (NPCM) and having a high surface-to-volume ratio geometry. The conceptual design is capable of reaching 105 W/cm3 using encapsulated nano-size phase change materials, which would result in an order of magnitude higher cooling capacity than typical microchannel heat sink of the same volume and same pumping power. It is also scalable to submicron range, resulting even higher cooling capacity. An analysis for a working model (10 × 10 × 1 mm) is presented utilizing energy conservation principle and uniform temperature and uniform heat flux boundary conditions. The average phase change heat transfer coefficient is obtained using the numerical model results. A process of micro electrochemical deposition to fabricate the target model is illustrated, and the issues associated with system-level applications are discussed.

Performance Analysis of an Ultrahigh Performance, 3-D Micro Convective Heat Sink With a Nearly Fractal Plumbing System

Volume 4 ◽  
2004 ◽  
Author(s):  
R. Moreno ◽  
Y.-X. Tao
Keyword(s):  
Convective Heat ◽  
Heat Sink ◽  
High Performance ◽  
Silver Film ◽  
High Surface ◽  
Tape Casting ◽  
Volume Ratio ◽  
Pumping Power ◽  
Flow And Heat Transfer ◽  
Point To Point

This paper presents the design and CFD analysis of a 3-D, active micro convective heat sink having high surface-to-volume ratio geometry. The heat sink consists of an array of elemental units arranged in parallel. Each unit is constructed as a network of nearly fractal geometry. The design of each unit uses the constructal method to minimize the point-to-point temperature difference within the heat sink and Murray’s Law to minimize pressure drop across the device. The heat sink is designed for the tape casting fabrication method using thick silver film techniques and co–fired with low temperature co-fired ceramic substrate. To analyze fluid flow and heat transfer characteristics of the design, we use the Fluent CFD software. The numerical results are presented to validate the theoretical optimization and outline the ultra-high performance characteristics of the heat sink such as the overall thermal resistance, pumping power and effectiveness.

Experimental Study of an Ultra-High Performance, 3-D Micro Convective Heat Sink With a Constructal Plumbing System

2004 ◽  
Author(s):  
R. Moreno ◽  
Y.-X. Tao
Keyword(s):  
Experimental Study ◽  
Pressure Drop ◽  
Convective Heat ◽  
Heat Sink ◽  
High Performance ◽  
Theoretical Calculations ◽  
High Surface ◽  
Tape Casting ◽  
Volume Ratio ◽  
Point To Point

This paper presents the fabrication and results of an experimental study carried out to determine the thermal fluid performance of a 3-D, active micro convective heat sink having high surface-to-volume ratio geometry. The heat sink consists of an array of elemental units arranged in parallel. Each unit is constructed as a network of nearly fractal geometry. The design of each unit uses the constructal method to minimize the point-to-point temperature difference within the heat sink and Murray’s Law to minimize pressure drop across the device. One elemental unit of the heat sink was manufactured using the tape casting fabrication method with thick silver film techniques. An experiment was conducted using water as the coolant under laminar flow conditions to obtain the pressure drop and heat transfer characteristics of the 3-D micro convective heat sink. The results were then compared with theoretical calculations.

Thermal Contact Resistance of Phase Change and Grease Type Polymeric Materials

2000 ◽  
Author(s):  
Ravi S. Prasher ◽  
Craig Simmons ◽  
Gary Solbrekken
Keyword(s):  
Thermal Conductivity ◽  
Contact Resistance ◽  
Phase Change ◽  
High Performance ◽  
Phase Change Materials ◽  
Thermal Contact ◽  
Polymeric Materials ◽  
Thermal Interface Material ◽  
Heat Spreader ◽  
Thermal Grease

Abstract Thermal interface material (TIM) between the die and the heat spreader or between the heat spreader and the heat sink in any electronic package plays a very important role in the thermal management of electronic cooling. Due to increased power and power density high-performance TIMs are sought every day. Phase change materials (PCM) seem to be very good alternative to traditionally used thermal greases because of various reasons. These phase change materials also have the advantage of being reworked easily without damaging the die. Typically these phase change materials are polymer based and are particle laden to enhance their thermal conductivity. The thermal conductivity of these materials is relatively well understood than their contact resistance. Current work focuses on explicitly measuring the contact resistance and the thermal conductivity of a particular phase change TIM and some silicon-based greases. Effect of various parameters, which can affect the contact resistance of theses TIMs and Greases, are also captured. The steady state measurements of the thermal conductivity and the contact resistance was done on an interface tester. In general the work on the contact resistance of fluid-like polymer based TIM, such as thermal grease or phase change polymer has been experimental in the past. A semi-analytical model, which captures the various parameters affecting the contact resistance of two class of materials; the phase change and the thermal grease is also developed in this paper. This model fits very well with the experimental data.

Magnetically tightened form-stable phase change materials with modular assembly and geometric conformality features

2021 ◽  
Author(s):  
Yongyu Lu ◽  
Dehai Yu ◽  
Haoxuan Dong ◽  
Jinran Lv ◽  
Lichen Wang ◽  
...  
Keyword(s):  
Phase Change ◽  
High Performance ◽  
Magnetic Particles ◽  
Phase Change Materials ◽  
Stable Phase ◽  
Free Standing ◽  
Modular Assembly ◽  
Significant Step ◽  
Dynamic Assembly ◽  
Surrounding Space

Abstract Recently, phase change materials (PCMs) have attracted significant attention due to their promising applications in many fields like solar energy and chip cooling. However, the present PCMs seriously suffer inevitable leakage and low thermal conduction. Magnetism can produce invisible field effects in the surrounding space. If there exist magnetic particles within this region, the effects will act on them emerging various fascinating phenomena. Inspired by this, we introduce hard magnetic particles (which can keep the effect after removing the magnetic field) to PCMs synthesizing an unprecedented magnetically tightened form-stable PCMs (MTPCMs), achieving multifunctions of leakage-proof, dynamic assembly and morphological reconfiguration, superior high thermal (increasing of 1400%~1600%) and electrical (>104 S/m) conductivity, and prominent compressive strength. Novel free-standing temperature control and high-performance thermal and electric conversion systems based on MTPCMs are furthermore developed. This work is a significant step toward exploiting a smart PCM for electronics and low-temperature energy storage.

Evaluation of Phase Change Materials for Personal Cooling Applications

2021 ◽  
pp. 0887302X2110530
Author(s):  
Lennart Teunissen ◽  
Emiel Janssen ◽  
Joost Schootstra ◽  
Linda Plaude ◽  
Kaspar Jansen
Keyword(s):  
Phase Change ◽  
Phase Change Materials ◽  
Cooling Capacity ◽  
Packaging Material ◽  
Inorganic Salts ◽  
Cooling Power ◽  
Water Based ◽  
Similar Content ◽  
Personal Cooling ◽  
Power Segmentation

Eleven phase change materials (PCMs) for cooling humans in heat-stressed conditions were evaluated for their cooling characteristics. Effects of packaging material and segmentation were also investigated. Sample packs with a different type PCM (water- and oil-based PCMs, cooling gels, inorganic salts) or different packaging (aluminum, TPU, TPU + neoprene) were investigated on a hotplate. Cooling capacity, duration, and power were determined. Secondly, a PCM pack with hexagon compartments was compared to an unsegmented version with similar content. Cooling power decreased whereas cooling duration increased with increasing melting temperature. The water-based PCMs showed a >2x higher cooling power than other PCMs, but were relatively short-lived. The flexible gels and salts did not demonstrate a phase change plateau in cooling power, compromising their cooling potential. Using a TPU or aluminum packaging was indifferent. Adding neoprene considerably extended cooling duration, while decreasing power. Segmentation has practical benefits, but substantially lowered contact area and therefore cooling power.

High-performance composite phase change materials for energy conversion based on macroscopically three-dimensional structural materials

2019 ◽  
Vol 6 (2) ◽  
pp. 250-273 ◽  
Author(s):  
Jie Yang ◽  
Li-Sheng Tang ◽  
Lu Bai ◽  
Rui-Ying Bao ◽  
Zheng-Ying Liu ◽  
...  
Keyword(s):  
Phase Change ◽  
Energy Conversion ◽  
High Performance ◽  
Phase Change Materials ◽  
Three Dimensional ◽  
Structural Materials ◽  
Shape Stability ◽  
Efficient Energy ◽  
Composite Phase Change Materials ◽  
High Performance Composite

Macroscopically three-dimensional structural materials endow composite phase change materials with enhanced comprehensive performance, including excellent shape stability, high thermal conductivity and efficient energy conversion.

Merits of Employing Foam Encapsulated Phase Change Materials for Pulsed Power Electronics Cooling Applications

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
K. Lafdi ◽  
O. Mesalhy ◽  
A. Elgafy
Keyword(s):  
Phase Change ◽  
Heat Sink ◽  
Phase Change Materials ◽  
Electronics Cooling ◽  
Volume Averaging ◽  
Equation Model ◽  
Heat Diffusion ◽  
Solid Matrix ◽  
Design Parameters ◽  
Heat Diffusion Equation

In the present work, the potential of using foam structures impregnated with phase change materials (PCMs) as heat sinks for cooling of electronic devices has been numerically studied. Different design parameters have been investigated such as foam properties (porosity, pore size, and thermal conductivity), heat sink shape, orientation, and use of internal fins inside the foam-PCM composite. Due to huge difference in thermal properties between the PCM and the solid matrix, two energy equation model has been adopted to solve the energy conservation equations. This model can handle local thermal nonequilibrium condition between the PCM and the solid matrix. The numerical model is based on volume averaging technique, and the finite volume method is used to discretize the heat diffusion equation. The findings show that, for steady heat generation, the shape and orientation of the composite heat sink have significant impact on the system performance. Conversely, in the case of power spike input, use of a PCM with low melting point and high latent heat is more efficient.

A Comparative Numerical Study on Two-Phase Boiling Fluid Flow and Heat Transfer in the Microchannel Heat Sink With Different Manifold Arrangements

2020 ◽  
Author(s):  
Yang Luo ◽  
Jingzhi Zhang ◽  
Wei Li
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Heat Sink ◽  
Numerical Study ◽  
Flow Boiling ◽  
High Surface ◽  
Volume Ratio ◽  
High Heat Flux ◽  
Two Phase ◽  
Flow Maldistribution

Abstract The manifold microchannel (MMC) heat sink system has been widely used in high-heat-flux chip thermal management due to its high surface-to-volume ratio. Two-phase, three-dimensional numerical methods for subcooled flow boiling have been developed using a self-programming solver based on OpenFOAM. Four different types of manifold arrangements (Z-type, C-type, H-type and U-type) have been investigated at a fixed operational condition. The numerical results evaluate the effects of flow maldistribution caused by different manifold configurations. Before simulating the two-phase boiling flow in MIMC metamodels, single-phase liquid flow fields are performed at first to compare the flow maldistribution in microchannels. It can be concluded from the flow patterns that H-type and U-type manifolds provide a more even and a lower microchannel void fraction, which is conducive to improving the temperature uniformity and decreasing the effective thermal resistance. The simulation results also show that the wall temperature difference of H-type (0.471 K) is only about 10% of the Z-type (4.683 K). In addition, the U-type manifold configuration show the lowest average pressure drop at the inlet and outlet of the MIMC metamodel domain. However, H-type manifold also shows an impressive 59.9% decrease in pressure loss. Results indicate that both the H-type and the U-type manifolds for flow boiling in microchannels are recommended due to their better heat transfer performance and lower pressure drop when compared with Z-type and C-type.

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