High-performance Planar Thermal Diode with Wickless Components

2021 ◽  
Author(s):  
George Damoulakis ◽  
Mohamad Jafari-Gukeh ◽  
Theodore P. Koukoravas ◽  
Constantine Megaridis
Keyword(s):  
Thermal Management ◽  
High Performance ◽  
Building Materials ◽  
Condensed Medium ◽  
Thermal Control ◽  
Electronics Packaging ◽  
Vapor Chamber ◽  
Reverse Mode ◽  
Low Profile ◽  
Specific Direction

Abstract The characterization "thermal diode" has been used to portray systems that spread heat very efficiently in a specific direction but obstruct it from flowing in the opposite direction. In this study, a planar vapor chamber with a wickless, wettability-patterned condenser is fabricated and tested as a thermal diode. When the chamber operates in the forward mode, heat is naturally driven away from the heat source; in the reverse mode, the system blocks heat backflow, thus working as a thermal diode. The low-profile assembly takes advantage of the phase-changing properties of water inside a closed loop comprised of a classical thin-wick evaporator opposing a wickless wettability-patterned condenser, when the chamber operates in the forward (heat-transporting) mode. The wettability patterned plate -when on the cooled side- enables spatial controlled dropwise and filmwise condensation and offers an efficient transport mechanism of the condensed medium on superhydrophilic wedge tracks by way of capillary forces. The same chamber acts as a thermal blocker when the opposing wick-covered plate is on the cool side, trapping the liquid in the pores and blocking heat flow. With this system, thermal diodicities exceeding 20 have been achieved, and are tunable by altering the wettability pattern as needed for different purposes. The present vapor chamber - thermal diode design could be well-suited for an extensive range of thermal-management applications, ranging from aerospace, spacecraft, and construction building materials, to electronics protection, electronics packaging, refrigeration, thermal control during energy harvesting, thermal isolation, etc.

scholarly journals Micro channels in macro thermal management solutions

2006 ◽  
Vol 10 (1) ◽  
pp. 81-98
Author(s):  
Boris Kosoy
Keyword(s):  
Surface Roughness ◽  
Thermal Management ◽  
High Performance ◽  
Electronic Device ◽  
Three Dimensional ◽  
Thermal Control ◽  
Consumer Products ◽  
Working Fluid ◽  
Channel Height ◽  
Micro Channels

Modern progress in electronics is associated with increase in computing ability and processing speed, as well as decrease in size. Future applications of electronic devices in aviation, aero space and high performance consumer products? industry demand on very stringent specifications concerning miniaturization, component density, power density and reliability. Excess heat produces stresses on internal components inside the electronic device, thus creating reliability problems. Thus, a problem of heat generation and its efficient removal arises and it has led to the development of advanced thermal control systems. Present research analyses a thermodynamic feasibility of micro capillary heat pumped net works in thermal management of electronic systems, considers basic technological constrains and de sign availability, and identifies perspective directions for the further studies. Computer Fluid Dynamics studies have been per formed on the laminar convective heat transfer and pressure drop of working fluid in silicon micro channels. Surface roughness is simulated via regular constructal, and stochastic models. Three-dimensional numerical solution shows significant effects of surface roughness in terms of the rough element geometry such as height, size, spacing and the channel height on the velocity and pressure fields.

FINLESS Heat Sinks, High Performance and Low Cost for Low Profile Cooling Applications

2011 ◽  
Author(s):  
Ed Walsh ◽  
Ronan Grimes ◽  
Patrick Walsh ◽  
Jason Stafford
Keyword(s):  
Heat Transfer ◽  
Thermal Management ◽  
High Performance ◽  
Imaging Techniques ◽  
Low Cost ◽  
Local Heat Transfer ◽  
Consumer Products ◽  
Laminar Flows ◽  
Transfer Coefficients ◽  
Low Profile

The need for low profile, sustainable thermal management solutions is becoming a critical need in electronics from consumer products to server cabinets. This work presents a FINLESS thermal management solution that utilises fluidic structures generated within it to enhance the heat transfer performance. The FINLESS thermal management solution can be manufactured to have a height of ∼5mm or even less when using low profile motors. Particle Image Velocimetry (PIV) combined with Infra-Red (IR) imaging techniques are used to explain the underlying flow physics that results in increased heat transfer rates compared to typical laminar flows. It is found that the local heat transfer coefficients in the finless design are up to 300% greater than those achieved at the same Reynolds number using conventional boundary layer theory. The additional benefits in terms of sustainability of the approach are also highlighted.

scholarly journals Recent Advances in Thermal Metamaterials and Their Future Applications for Electronics Packaging

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Jae Choon Kim ◽  
Zongqing Ren ◽  
Anil Yuksel ◽  
Ercan M. Dede ◽  
Prabhakar R. Bandaru ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Thermal Management ◽  
High Performance ◽  
State Of The Art ◽  
Electronics Packaging ◽  
The State ◽  
Future Research ◽  
Conductive Heat ◽  
Recent Advances ◽  
Conventional Cooling

Abstract Thermal metamaterials exhibit thermal properties that do not exist in nature but can be rationally designed to offer unique capabilities of controlling heat transfer. Recent advances have demonstrated successful manipulation of conductive heat transfer and led to novel heat guiding structures such as thermal cloaks, concentrators, etc. These advances imply new opportunities to guide heat transfer in complex systems and new packaging approaches as related to thermal management of electronics. Such aspects are important, as trends of electronics packaging toward higher power, higher density, and 2.5D/3D integration are making thermal management even more challenging. While conventional cooling solutions based on large thermal-conductivity materials as well as heat pipes and heat exchangers may dissipate the heat from a source to a sink in a uniform manner, thermal metamaterials could help dissipate the heat in a deterministic manner and avoid thermal crosstalk and local hot spots. This paper reviews recent advances of thermal metamaterials that are potentially relevant to electronics packaging. While providing an overview of the state-of-the-art and critical 2.5D/3D-integrated packaging challenges, this paper also discusses the implications of thermal metamaterials for the future of electronic packaging thermal management. Thermal metamaterials could provide a solution to nontrivial thermal management challenges. Future research will need to take on the new challenges in implementing the thermal metamaterial designs in high-performance heterogeneous packages to continue to advance the state-of-the-art in electronics packaging.

scholarly journals A Review on the Development of Rotman Lens Antenna

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Shruti Vashist ◽  
M. K. Soni ◽  
P. K. Singhal
Keyword(s):  
High Performance ◽  
Beam Steering ◽  
Phase Error ◽  
Antenna System ◽  
Surveillance Systems ◽  
Electronic Warfare ◽  
Design Concepts ◽  
Low Profile ◽  
True Time ◽  
The One

Rotman lenses are the beguiling devices used by the beamforming networks (BFNs). These lenses are generally used in the radar surveillance systems to see targets in multiple directions due to its multibeam capability without physically moving the antenna system. Now a days these lenses are being integrated into many radars and electronic warfare systems around the world. The antenna should be capable of producing multiple beams which can be steered without changing the orientation of the antenna. Microwave lenses are the one who support low-phase error, wideband, and wide-angle scanning. They are the true time delay (TTD) devices producing frequency independent beam steering. The emerging printed lenses in recent years have facilitated the advancement of designing high performance but low-profile, light-weight, and small-size and networks (BFNs). This paper will review and analyze various design concepts used over the years to improve the scanning capability of the lens developed by various researchers.

Exergy Analysis of Data Center Thermal Management Systems

2003 ◽  
Author(s):  
Amip J. Shah ◽  
Van P. Carey ◽  
Cullen E. Bash ◽  
Chandrakant D. Patel
Keyword(s):  
Thermal Management ◽  
Data Center ◽  
Data Centers ◽  
Exergy Analysis ◽  
Thermal Control ◽  
Management Systems ◽  
World Systems ◽  
Sample Data ◽  
Potential Applications ◽  
Temperature Ranges

Data centers today contain more computing and networking equipment than ever before. As a result, a higher amount of cooling is required to maintain facilities within operable temperature ranges. Increasing amounts of resources are spent to achieve thermal control, and tremendous potential benefit lies in the optimization of the cooling process. This paper describes a study performed on data center thermal management systems using the thermodynamic concept of exergy. Specifically, an exergy analysis has been performed on sample data centers in an attempt to identify local and overall inefficiencies within thermal management systems. The development of a model using finite volume analysis has been described, and potential applications to real-world systems have been illustrated. Preliminary results suggest that such an exergy-based analysis can be a useful tool in the design and enhancement of thermal management systems.

Empty Substrate‐Integrated Waveguides: A Low‐Cost and Low‐Profile Alternative for High‐Performance Microwave Devices

2020 ◽  
pp. 1-23
Author(s):  
Ángel Belenguer ◽  
Héctor Esteban ◽  
Alejandro L. Borja ◽  
José A. Ballesteros ◽  
Marcos Fernández ◽  
...  
Keyword(s):  
High Performance ◽  
Low Cost ◽  
Microwave Devices ◽  
Substrate Integrated Waveguides ◽  
Low Profile
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