Experimental comparison of fluid and thermal characteristics of microchannel and metal foam heat sinks

Download
2011
Ateş, Ahmet Muaz
Doubling transistor count for every two years in a computer chip, transmitter and receiver (T/R) module of a phased-array antenna that demands higher power with smaller dimensions are all results of miniaturization in electronics packaging. These technologies nowadays depend on improvement of reliable high performance heat sink to perform in narrower volumes. Employing microchannels or open cell metal foam heat sinks are two recently developing promising methods of cooling high heat fluxes. Although recent studies especially on microchannels can give a rough estimate on performances of these two methods, since using metal foams as heat sinks is still needed further studies, a direct experimental comparison of heat exchanger performances of these two techniques is still needed especially for thermal design engineers to decide the method of cooling. For this study, microchannels with channel widths of 300 µm, 420 µm, 500 µm and 900 µm were produced. Also, 92% porous 10, 20 and 40 ppi 6101-T6 open cell aluminum metal foams with compression factors 1,2, and 3 that have the same finned volume of microchannels with exactly same dimensions were used to manufacture heat sinks with method of vacuum brazing. They all have tested under same conditions with volumetric flow rate ranging from 0,167 l/min to 1,33 l/min and 60 W of heat power. Channel height was 4 mm for all heat sinks and distilled water used as cooling fluid. After experiments, pressure drops and thermal resistances were compared with tabulated and graphical forms. Also, the use of metal foam and microchannel heat sinks were highlighted with their advantages and disadvantages for future projects.

Suggestions

Cmos class e power amplifier modelling and design including channel resistance effects
Demir, İbrahim; Demir, Şimşek; Department of Electrical and Electronics Engineering (2004)
CMOS is the favorite candidate process for the high integration of the wireless communication IC blocks, RF frontend and digital baseband circuitry. Also the design of the RF power amplifier stage is the one of the most important part of the RF CMOS circuit design. Since high frequency and high power simultaneously exists on this stage, devices works on the limits of the process. Therefore standard device models may not be valid enough for a successful design. In the thesis high frequency passive device and...
Millimeter wave gunn diode oscillators
Lüy, Ülkü; Toker, Canan; Department of Electrical and Electronics Engineering (2007)
This thesis presents the design and implementation of a millimeter-wave Gunn diode oscillator operating at 35 GHz (Ka (R) 26.5-40 GHz Band). The aim of the study is to produce a high frequency, high power signal from a negative resistance device situated in a waveguide cavity by applying a direct current bias. First the physics of Gunn diodes is studied and the requirements that Gunn diode operates within the negative differential resistance region is obtained. Then the best design configuration is selected...
Optimization of a heat sink with heterogeneous heat flux boundary condition
Turgut, Eren; Güvenç Yazıcıoğlu, Almıla; Department of Mechanical Engineering (2019)
Advancements in micro/nanotechnology along with the size reduction in avionics, raise the importance of microchannel heat sink utilization in the field of electronics cooling. The usage of conventional uniform pin fin arrays or microchannels in the presence of non-uniform heating conditions are not sufficient to overcome the occurrence of the hotspots. Consequently, significant temperature gradients take place at the surface to be cooled. In this study, the effects of some design parameters on the non-unifo...
Milimeter wave microstrip launchers and antenna arrays
Akgün, Erdem; Hızal, Altunkan; Department of Electrical and Electronics Engineering (2006)
Coaxial-to-microstrip launcher and microstrip patch array antenna are designed to work at center frequency of 36.85 GHz with a bandwidth higher than 300 MHz. The antenna array design also includes the feeding network distributing the power to each antenna element. The design parameters are defined on this report and optimized by using an Electromagnetic Simulation software program. In order to verify the theoretical results, microstrip patch array antenna is produced as a prototype. Measurements of antenna ...
Analysis and design of passive microwave and optical devices using the multimode interference technique
Sunay, Ahmet Sertaç; Birand, Mehmet Tuncay; Department of Electrical and Electronics Engineering (2005)
The Multimode Interference (MMI) mechanism is a powerful toool used in the analysis and design of a certain class of optical, microwave and millimeter wave devices. The principles of the MMI method and the self-imaging principle is described. Using this method, NXM MMI couplers, MMI splitter/combiners are analyzed. Computer simulations for illustrating the "Multimode Interference Mechanism" are carried out. The MMI approach is used to analyze overmoded 'rectangular metallic' and 'dielectric slab' type of wa...
Citation Formats
A. M. Ateş, “Experimental comparison of fluid and thermal characteristics of microchannel and metal foam heat sinks,” M.S. - Master of Science, Middle East Technical University, 2011.