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.

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.

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.

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.

scholarly journals Design Considerations for Borehole Thermal Energy Storage (BTES): A Review with Emphasis on Convective Heat Transfer

Geofluids ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-26 ◽  
Author(s):  
Helge Skarphagen ◽  
David Banks ◽  
Bjørn S. Frengstad ◽  
Harald Gether
Keyword(s):  
Energy Storage ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Theoretical Calculations ◽  
High Surface ◽  
High Surface Area ◽  
Volume Ratio ◽  
Thermal Recovery ◽  
Conductive Heat ◽  
Geological Environment

Borehole thermal energy storage (BTES) exploits the high volumetric heat capacity of rock-forming minerals and pore water to store large quantities of heat (or cold) on a seasonal basis in the geological environment. The BTES is a volume of rock or sediment accessed via an array of borehole heat exchangers (BHE). Even well-designed BTES arrays will lose a significant quantity of heat to the adjacent and subjacent rocks/sediments and to the surface; both theoretical calculations and empirical observations suggest that seasonal thermal recovery factors in excess of 50% are difficult to obtain. Storage efficiency may be dramatically reduced in cases where (i) natural groundwater advection through the BTES removes stored heat, (ii) extensive free convection cells (thermosiphons) are allowed to form, and (iii) poor BTES design results in a high surface area/volume ratio of the array shape, allowing high conductive heat losses. The most efficient array shape will typically be a cylinder with similar dimensions of diameter and depth, preferably with an insulated top surface. Despite the potential for moderate thermal recovery, the sheer volume of thermal storage that the natural geological environment offers can still make BTES a very attractive strategy for seasonal thermal energy storage within a “smart” district heat network, especially when coupled with more efficient surficial engineered dynamic thermal energy stores (DTES).

An Analytical Study of the Optimized Performance of an Impingement Heat Sink

2004 ◽  
Vol 126 (4) ◽  
pp. 528-534 ◽  
Author(s):  
S. B. Sathe ◽  
B. G. Sammakia
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Heat Sink ◽  
High Performance ◽  
Cross Flow ◽  
High Heat ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
High Heat Transfer ◽  
Flow Through

The results of a study of a new and unique high-performance air-cooled impingement heat sink are presented. An extensive numerical investigation of the heat sink performance is conducted and is verified by experimental data. The study is relevant to cooling of high-power chips and modules in air-cooled environments and applies to workstations or mainframes. In the study, a rectangular jet impinges on a set of parallel fins and then turns into cross flow. The effects of the fin thickness, gap nozzle width and fin shape on the heat transfer and pressure drop are investigated. It is found that pressure drop is reduced by cutting the fins in the central impingement zone without sacrificing the heat transfer due to a reduction in the extent of the stagnant zone. A combination of fin thicknesses of the order of 0.5 mm and channel gaps of 0.8 mm with appropriate central cutout yielded heat transfer coefficients over 1500 W/m2 K at a pressure drop of less than 100 N/m2, as is typically available in high-end workstations. A detailed study of flow-through heat sinks subject to the same constraints as the impingement heat sink showed that the flow-through heat sink could not achieve the high heat transfer coefficients at a low pressure drop.

Semimetallic vanadium molybdenum sulfide for high-performance battery electrodes

2018 ◽  
Vol 6 (20) ◽  
pp. 9411-9419 ◽  
Author(s):  
Qingfeng Zhang ◽  
Longlu Wang ◽  
Jue Wang ◽  
Xinzhi Yu ◽  
Junmin Ge ◽  
...  
Keyword(s):  
Lithium Ion Batteries ◽  
Electrode Material ◽  
High Performance ◽  
High Surface ◽  
Volume Ratio ◽  
Lithium Ion ◽  
Diffusion Path ◽  
Molybdenum Sulfide ◽  
Two Dimensional

The ultrathin thickness and lateral morphology of a two dimensional (2D) MoS2 nanosheet contribute to its high surface-to-volume ratio and short diffusion path, rendering it a brilliant electrode material for lithium-ion batteries (LIBs).

One-dimensional inorganic semiconductor nanostructures: A new carrier for nanosensors

2010 ◽  
Vol 82 (11) ◽  
pp. 2185-2198 ◽  
Author(s):  
Xiaosheng Fang ◽  
Linfeng Hu ◽  
Changhui Ye ◽  
Lide Zhang
Keyword(s):  
High Performance ◽  
High Surface ◽  
Volume Ratio ◽  
Semiconductor Nanostructures ◽  
One Dimensional ◽  
Semiconductor Nanostructure ◽  
Research Activities ◽  
Wide Range ◽  
Inorganic Semiconductor ◽  
Art Research

One-dimensional (1D) inorganic semiconductor nanostructures have witnessed an explosion of interest over the last decade because of advances in their controlled synthesis and unique property and potential applications. A wide range of gases, chemicals, biomedical nanosensors, and photodetectors have been assembled using 1D inorganic semiconductor nanostructures. The high-performance characteristics of these nanosensors are particularly attributable to the inorganic semiconducting nanostructure high surface-to-volume ratio (SVR) and its rationally designed surface. In this review, we provide a brief summary of the state-of-the-art research activities in the field of 1D inorganic semiconductor nanostructure-based nanosensors. Some perspectives and the outlook for future developments in this area are presented.

Sign in / Sign up

Export Citation Format

Share Document