Full Scale Simulation of an Integrated Monolithic Heat Sink for Thermal Management of a High Power Density GaN-SiC Chip

2015 ◽  
Author(s):  
Tanya Liu ◽  
Farzad Houshmand ◽  
Catherine Gorle ◽  
Sebastian Scholl ◽  
Hyoungsoon Lee ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Thermal Management ◽  
Power Density ◽  
Mass Flow ◽  
High Power ◽  
Heat Sink ◽  
High Power Density ◽  
Flow Rates ◽  
Mass Flow Rates ◽  
Insight Into

Advances in manufacturing techniques are inspiring the design of novel integrated microscale thermal cooling devices seeking to push the limits of current thermal management solutions in high heat flux applications. These advanced cooling technologies can be used to improve the performance of high power density electronics such as GaN-based RF power amplifiers. However, their optimal design requires careful analysis of the combined effects of conduction and convection. Many numerical simulations and optimization studies have been performed for single cell models of microchannel heat sinks, but these simulations do not provide insight into the flow and heat transfer through the entire device. This study therefore presents the results of conjugate heat transfer CFD simulations for a complex copper monolithic heat sink integrated with a 100 micron thick, 5 mm by 1 mm high power density GaN-SiC chip. The computational model (13 million cells) represents both the chip and the heat sink, which consists of multiple inlets and outlets for fluid entry and exit, delivery and collection manifold systems, and an array of fins that form rectangular microchannels. Total chip powers of up to 150 W at the GaN gates were considered, and a quarter of the device was modeled for total inlet mass flow rates of 1.44 g/s and 1.8 g/s (0.36 g/s and 0.45 g/s for the quarter device), corresponding to laminar flow at Reynolds numbers between 19.5 and 119.3. It was observed that the mass flow rates through individual microchannels in the device vary by up to 45%, depending on the inlet/outlet locations and pressure drop in the manifolds. The results demonstrate that full device simulations provide valuable insight into the multiple parameters that affect cooling performance.

scholarly journals THE ADVANTAGES OF EVAPORATION IN MICRO-SCALE CHANNELS TO COOL MICROELETRONIC DEVICES

2007 ◽  
Vol 6 (2) ◽  
pp. 34 ◽  
Author(s):  
G. Ribatski ◽  
L. Cabezas-Gómez ◽  
H. A. Navarro ◽  
J. M. Saíz-Jabardo
Keyword(s):  
Specific Heat ◽  
Thermal Management ◽  
Power Density ◽  
High Power ◽  
Heat Sink ◽  
Flow Boiling ◽  
Electronic Devices ◽  
Management Systems ◽  
High Power Density ◽  
Micro Scale

In this paper, the importance of the development of new high power density thermal management systems for electronic devices is assessed. It is described the new heat sink technologies under development to be used in the cooling of microprocessors. The main difficulties to be overcome before the spreading of one specific heat sink configuration are identified. At the end, it is concluded that a heat sink based on flow boiling in micro-scale channels is the most promising approach.

Transient Heat Transfer in Microscale Porous Materials Heated by Microsecond Laser Pulse of High Power Density

2002 ◽  
Author(s):  
Fangming Jiang ◽  
Dengying Liu ◽  
Jim S.-J. Chen ◽  
Richard S. Cohen
Keyword(s):  
Heat Transfer ◽  
Heat Conduction ◽  
Laser Pulse ◽  
Power Density ◽  
High Power ◽  
Hyperbolic Model ◽  
Transient Temperature ◽  
Hyperbolic Heat Conduction ◽  
High Power Density ◽  
High Heat Transfer

A novel experimental method was developed to measure the rapid transient temperature variations (heating rate > 107 K/s) of porous samples heated by high surface heat fluxes. With a thin film (0.1 μm thick) resistance thermometer of platinum as the temperature sensor and a super-high speed digital oscilloscope (up to 100 MHz) as the data recorder, rapid transient temperature variation in a porous material heated by a microsecond laser pulse of high power density is measured. Experimental results indicate that for high heat transfer cases (q′ > 109 W/m2) with short durations (5 – 20 μs) of heating, non-Fourier heat conduction behaviors appear. The non-Fourier hyperbolic heat conduction model and the traditional Fourier parabolic model are employed to simulate this thermal case respectively and the FDM is used to perform the numerical analysis. The hyperbolic model predicts thermal wave behavior in qualitative agreement with the experimental data.

scholarly journals Advanced Thermal Management for High Power Density Electronics

2017 ◽  
Author(s):  
Nenad Miljkovic ◽  
Thomas Foulkes ◽  
Junho Oh ◽  
Patrick Birbarah ◽  
Robert Pilawa-Podgurski ◽  
...  
Keyword(s):  
Thermal Management ◽  
Power Density ◽  
High Power ◽  
High Power Density

Application of the Transient Heat Transfer Measurement Technique Using TLC in a Network Configuration With Intersecting Circular Passages

2018 ◽  
Author(s):  
Anika Steurer ◽  
Rico Poser ◽  
Jens von Wolfersdorf ◽  
Stefan Retzko
Keyword(s):  
Heat Transfer ◽  
Steady State ◽  
Mass Flow ◽  
Fluid Temperature ◽  
Thermochromic Liquid Crystal ◽  
Transfer Coefficients ◽  
Flow Rates ◽  
Flow Network ◽  
Mass Flow Rates ◽  
Time Information

The present study deals with the application of the transient thermochromic liquid crystal (TLC) technique in a flow network of intersecting circular passages as a potential internal turbine component cooling geometry. The investigated network consists of six circular passages with a diameter d = 20mm that intersect coplanar at an angle θ = 40°, the innermost in three, the outermost in one intersection level. Two additional non-intersecting passages serve as references. Such a flow network entails specific characteristics associated with the transient TLC method that have to be accounted for in the evaluation process: the strongly curved surfaces, the mixing and mass flow redistribution at each intersection point, and the resulting gradients between the wall and passage centerline temperatures. All this impedes the choice of a representative fluid reference temperature, which results in deviations using established evaluation methods. An alternative evaluation approach is introduced, which is supported by computational results obtained from steady-state three-dimensional RANS simulations using the SST turbulence model. The presented analysis uncouples local heat transfer coefficients from actually measured local temperatures but uses the time information of the thermocouples instead that represents the fluid temperature step change and evolution along the passages. This experimental time information is transferred to the steady-state numerical bulk temperatures, which are finally used as local references to evaluate the transient TLC experiments. As effective local mass flow rates in the passage sections are considered, the approach eventually allows for a conclusion whether heat transfer is locally enhanced due to higher mass flow rates or the intersection effects.

Embedded Microjets for Thermal Management of High Power-Density Electronic Devices

2019 ◽  
Vol 9 (2) ◽  
pp. 269-278 ◽  
Author(s):  
Stephen M. Walsh ◽  
Bernard A. Malouin ◽  
Eric A. Browne ◽  
Kevin R. Bagnall ◽  
Evelyn N. Wang ◽  
...  
Keyword(s):  
Thermal Management ◽  
Power Density ◽  
High Power ◽  
Electronic Devices ◽  
High Power Density

First and second thermodynamic law analyses applied to a solar dish collector

2014 ◽  
Vol 39 (4) ◽  
Author(s):  
Vahid Madadi ◽  
Touraj Tavakoli ◽  
Amir Rahimi
Keyword(s):  
Heat Transfer ◽  
Solar Radiation ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Exergy Efficiency ◽  
Exergy Destruction ◽  
Flow Rates ◽  
Energy And Exergy ◽  
Mass Flow Rates

AbstractThe energy and exergy performance of a parabolic dish collector is investigated experimentally and theoretically. The effect of receiver type, inlet temperature and mass flow rate of heat transfer fluid (HTF), receiver temperature, receiver aspect ratio and solar radiation are investigated. To evaluate the effect of the receiver aperture area on the system performance, three aperture diameters are considered. It is deduced that the fully opened receivers have the greatest exergy and thermal efficiency. The cylindrical receiver has greater energy and exergy efficiency than the conical one due to less exergy destruction. It is found that the highest exergy destruction is due to heat transfer between the sun and the receivers and counts for 35 % to 60 % of the total wasted exergy. For three selected receiver aperture diameters, the exergy efficiency is minimum for a specified HTF mass flow rate. High solar radiation allows the system to work at higher HTF inlet temperatures. To use this system in applications that need high temperatures, in cylindrical and conical receivers, the HTF mass flow rates lower than 0.05 and 0.09 kg/s are suggested, respectively. For applications that need higher amounts of energy content, higher HTF mass flow rates than the above mentioned values are recommended.

Enhanced Miniature Loop Heat Pipe Cooling System for High Power Density Electronics

2012 ◽  
Vol 4 (2) ◽  
Author(s):  
J. H. Choi ◽  
B. H. Sung ◽  
J. H. Yoo ◽  
C. J. Kim ◽  
D.-A. Borca-Tasciuc
Keyword(s):  
Heat Transfer ◽  
Thermal Resistance ◽  
Power Density ◽  
Thermal Performance ◽  
High Power ◽  
Design Stage ◽  
Working Fluid ◽  
High Power Density ◽  
Graphic Processing Units ◽  
Maximum Heat

The implementation of high power density, multicore central and graphic processing units (CPUs and GPUs) coupled with higher clock rates of the high-end computing hardware requires enhanced cooling technologies able to attend high heat fluxes while meeting strict design constrains associated with system volume and weight. Miniature loop heat pipes (mLHP) emerge as one of the technologies best suited to meet all these demands. Nonetheless, operational problems, such as instable behavior during startup on evaporator side, have stunted the advent of commercialization. This paper investigates experimentally two types of mLHP systems designed for workstation CPUs employing disk shaped and rectangular evaporators, respectively. Since there is a strong demand for miniaturization in commercial applications, emphasis was also placed on physical size during the design stage of the new systems. One of the mLHP system investigated here is demonstrated to have an increased thermal performance at a reduced system weight. Specifically, it is shown that the system can reach a maximum heat transfer rate of 170 W with an overall thermal resistance of 0.12 K/W. The corresponding heat flux is 18.9 W/cm2, approximately 30% higher than that of larger size commercial systems. The studies carried out here also suggest that decreasing the thermal resistance between the heat source and the working fluid and maximizing the area for heat transfer are keys for obtaining an enhanced thermal performance.

scholarly journals Verification and Improving the Heat Transfer Model in Radiators in the Wide Change Operating Parameters

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6543
Author(s):  
Mieczysław Dzierzgowski
Keyword(s):  
Heat Transfer ◽  
Mass Flow ◽  
Water Mass ◽  
Heat Transfer Model ◽  
Operating Conditions ◽  
Transfer Model ◽  
Flow Rates ◽  
Wide Range ◽  
Different Types ◽  
Mass Flow Rates

Laboratory measurements and analyses conducted in a wide range of changes of water temperature and mass flow rate for different types of radiators allowed to provides limitations and assessment of the current radiators heat transfer model according to EN 442. The inaccuracy to determinate the radiator heat output according to EN 442, in case of low water mass flow rates may achieve up to 22.3% A revised New Extended Heat Transfer Model in Radiators NEHTMiRmd is general and suitable for different types of radiators both new radiators and radiators existing after a certain period of operation is presented. The NEHTMiRmd with very high accuracy describes the heat transfer processes not only in the nominal conditions—in which the radiators are designed, but what is particularly important also in operating conditions when the radiators water mass flow differ significantly from the nominal value and at the same time the supply temperature changes in the whole range radiators operating during the heating season. In order to prove that the presented new model NEHTMiRmd is general, the article presents numerous calculation examples for various types of radiators currently used. Achieved the high compatibility of the results of the simulation calculations with the measurement results for different types of radiators: iron elements (not ribbed), plate radiators (medium degree ribbed), convectors (high degree ribbed) in a very wide range of changes in the water mass flow rates and the supply temperature indicates that a verified NEHTMiRmd can also be used in designing and simulating calculations of the central heating installations, for the rational conversion of existing installations and district heating systems into low temperature energy efficient systems as well as to directly determine the actual energy efficiency, also to improve the indications of the heat cost allocators. In addition, it may form the basis for the future modification of the European Standards for radiator testing.

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