Thermal Management for the 21st Century - Improved Thermal Control & amp; Fuel Economy in an Army Medium Tactical Vehicle

2005 ◽  
Author(s):  
Robert W. Page ◽  
Wsewolod “Jeep” Hnatczuk ◽  
Jeffrey Kozierowski
Keyword(s):  
Thermal Management ◽  
21St Century ◽  
Fuel Economy ◽  
Thermal Control ◽  
Tactical Vehicle

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.

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.

Application of thermal management technique to thermal control for ultraviolet imaging spectrometers

2014 ◽  
Vol 22 (7) ◽  
pp. 1877-1885
Author(s):  
郭亮 GUO Liang ◽  
吴清文 WU Qing-wen ◽  
黄勇 HUANG Yong ◽  
王淑荣 WANG Shu-rong
Keyword(s):  
Thermal Management ◽  
Thermal Control ◽  
Management Technique

Adaptive Thermal Conductivity Metamaterials: Enabling Active and Passive Thermal Control

2018 ◽  
Vol 10 (5) ◽  
Author(s):  
Austin A. Phoenix ◽  
Evan Wilson
Keyword(s):  
Thermal Conductivity ◽  
Thermal Management ◽  
Passive Control ◽  
Coefficient Of Thermal Expansion ◽  
Thermal Strain ◽  
Thermal Control ◽  
Variable Thermal Conductivity ◽  
Highly Nonlinear ◽  
Wide Range ◽  
Nonlinear Thermal Conductivity

The novel adaptive thermal metamaterial developed in this paper provides a unique thermal management capability that can address the needs of future spacecraft. While advances in metamaterials have provided the ability to generate materials with a broad range of material properties, relatively little advancement has been made in the development of adaptive metamaterials. This metamaterial concept enables the development of materials with a highly nonlinear thermal conductivity as a function of temperature. Through enabling active or passive control of the metamaterials bulk effective thermal conductivity, this metamaterial that can improve the spacecraft's thermal management systems performance. This variable thermal conductivity is achieved through induced contact that results in changes in the F path length and the conductive path area. The contact can be generated internally using thermal strain from shape memory alloys, bimetal springs, and mismatches in coefficient of thermal expansion (CTE) or it can be generated externally using applied mechanical loading. The metamaterial can actively control the temperature of an interface by dynamically changing the bulk thermal conductivity controlling the instantaneous heat flux through the metamaterial. The design of thermal stability regions (regions of constant thermal conductivity versus temperature) into the nonlinear thermal conductivity as a function of temperature can provide passive thermal control. While this concept can be used in a wide range of applications, this paper focuses on the development of a metamaterial that achieves highly nonlinear thermal conductivity as a function of temperature to enable passive thermal control of spacecraft systems on orbit.

scholarly journals EXPERIMENTAL INVESTIGATIONS OF ADSORBED NATURAL GAS STORAGE SYSTEM WITH ENHANCED THERMAL MANAGEMENT

2012 ◽  
Vol 19 ◽  
pp. 190-195 ◽  
Author(s):  
KAZI AFZALUR RAHMAN ◽  
WAI SOONG LOH ◽  
KIM CHOON NG ◽  
WONGEE CHUN
Keyword(s):  
Natural Gas ◽  
Thermal Management ◽  
Storage Capacity ◽  
Storage System ◽  
Thermal Control ◽  
Experimental Investigations ◽  
Discharge Process ◽  
Adsorbed Natural Gas ◽  
Charge Process ◽  
Tube Type

An adsorbed natural gas (ANG) storage system with internal thermal control, based on fin and tube type heat exchanger is investigated in this study. The adsorbent bed, which consists of Maxsorb III activated carbon packed in between copper fins and tubes, is demonstrated to study the storage capacity and thermal management of the ANG storage system. The cylinder is pressurized up to 35 bar and water is circulated through the tubes during charge process for quick removal of adsorption heat, thus to increase the storage capacity. Similarly, the adsorbent bed is heated up during discharge process to maximize the gas delivery. The current experimental arrangement presented shows higher storage capacity and better thermal management than the adsorbent bed without fin and tube arrangement.

Research of Strontium Silicate Modified Zinc Oxide Thermal Control Coatings

2013 ◽  
Vol 821-822 ◽  
pp. 1236-1239 ◽  
Author(s):  
Xiaoan Yue ◽  
Zheng Quan Zhang ◽  
En Ze Wang ◽  
Song Qin Xia
Keyword(s):  
Zinc Oxide ◽  
Optical Properties ◽  
Thermal Management ◽  
Near Infrared ◽  
Composite Coatings ◽  
Thermal Control ◽  
The Novel ◽  
Infrared Band ◽  
Thermal Control Coatings ◽  
Strontium Silicate

Thermal control coatings (TCCs) play an important role in thermal management of spacecrafts and satellites by their thermo-optical properties. In this research, the novel TCCs were prepared by incorporating the self-made strontium silicate and zinc oxide into the potassium silicate binder. The effects of strontium silicate on phase composition, microstructure and optical performance of TCCs were studied using scanning electron microscope and spectroreflectometer. The results show that: strontium silicate can improve near infrared band (1000~2400nm) spectra reflectance. Compared with traditional zinc oxide TCCs, the novel composite coatings enhance the reflectance , and improve the optical properties.

Enhancing the Performance of Photovoltaic Powered Reverse Osmosis Desalination Systems by Active Thermal Management

2011 ◽  
Author(s):  
Leah Kelley ◽  
Amy M. Bilton ◽  
Steven Dubowsky
Keyword(s):  
Thermal Management ◽  
Reverse Osmosis ◽  
Fresh Water ◽  
Low Cost ◽  
Simulation Models ◽  
Cost Effective ◽  
Thermal Control ◽  
Solar Panel ◽  
Experimental Results ◽  
Feed Water

Reverse osmosis (RO) is a well-known process for desalinating seawater and brackish groundwater. Desalination is energy-intensive, so using photovoltaic (PV) panels to power the process is an attractive and cost-effective concept, especially for community-scale systems. Increasing the system efficiency will lower the total cost of water produced, making the systems more economically competitive for a greater number of geographic locations. It is noted in this paper that the amount of water produced by a PV-powered RO (PVRO) system can be increased if the temperatures of the solar panel and the reverse osmosis feed water are actively managed. For a given level of solar radiation, a photovoltaic panel produces more power at a lower temperature. Also, for a given power, an RO system produces more clean water at a higher input (feed) water temperature. An active thermal management system is needed to exploit these complementary characteristics by cooling the solar panel and warming the RO feed water, increasing the amount of fresh water produced. This can be accomplished by running the RO feed water through a heat exchanger attached to the back of the solar panel, cooling it. Furthermore, the ability to cool the solar panels permits the addition of low-cost, flat-plate concentrating mirrors to be used with the PV panels, which further increases the PV power output. The flow of the water through the respective units must be actively controlled as there are limits for the maximum temperatures of both the RO water and PV panels. In this paper, a concept for an active PVRO thermal control system is presented. Simulations and experimental results show the effectiveness of this approach. In experiment, a 57% increase in fresh water production was achieved. These experimental results agree well with simulation models.

Thermal Management and Alignment Strategies in MEMS Tunable Laser Packaging

2009 ◽  
Vol 74 ◽  
pp. 319-322
Author(s):  
Ji Fang Tao ◽  
Jonathan Tamil ◽  
Jian Wu ◽  
Kun Xu ◽  
Jin Tong Lin ◽  
...  
Keyword(s):  
Thermal Management ◽  
Tunable Laser ◽  
Thermal Control ◽  
High Accuracy ◽  
Vertical Alignment ◽  
Thermo Electric ◽  
Laser Chip ◽  
Optical Alignment ◽  
Bonding Method ◽  
Packaging Cost

A packaging architecture is developed for MEMS tunable laser (MEMS-TL). The hybrid integration of chips is realized under high accuracy thermal control and precise alignment. The thermal conductivity of the laser chip has been improved up to 60% by the proper substrate design of device and epi-down bonding method. Under the analysis of heat flux, we employ a thermo-electric cooler (TEC) to stabilize the temperature. The substrate is designed to accommodate gain chips with minimal active optical alignment, thus reducing the packaging cost. With this packaging scheme, the insertion loss is greatly induced less than 1 dB due to the advantages of horizontal and vertical alignment in optical fiber fastening and laser diode bonding.

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.

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