Download or read book Active Heat Transfer Enhancement in Integrated Fan Heat Sinks written by Wayne Lawrence Staats and published by . This book was released on 2012 with total page 211 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modern computer processors require significant cooling to achieve their full performance. The "efficiency" of heat sinks is also becoming more important: cooling of electronics consumes 1% of worldwide electricity use by some estimates. Unfortunately, current cooling technologies often focus on improving heat transfer at the expense of efficiency. The present work focuses on a unique, compact, and efficient air cooled heat sink which addresses these shortcomings. While conventional air cooled heat sinks typically use a separate fan to force air flow over heated fins, the new design incorporates centrifugal fans directly into the body of a loop heat pipe with multiple planar condensers. These "integrated fans" rotate between the planar condensers, in close proximity to the hot surfaces, establishing a radially outward flow of cooling air. The proximity of the rotating impellers to the condenser surfaces results in a marked enhancement in the convective heat transfer coefficient without a large increase in input power. To develop an understanding of the heat transfer in integrated fan heat sinks, a series of experiments was performed to simultaneously characterize the fan performance and average heat transfer coefficients. These characterizations were performed for 15 different impeller profiles with various impeller-to-gap thickness ratios. The local heat transfer coefficient was also measured using a new heated-thin-film infrared thermography technique capable of applying various thermal boundary conditions. The heat transfer was found to be a function of the flow and rotational Reynolds numbers, and the results suggest that turbulent flow structures introduced by the fans govern the transport of thermal energy in the air. The insensitivity of the heat transfer to the impeller profile decouples the fan design from the convection enhancement problem, greatly simplifying the heat sink design process. Based on the experimental results, heat transfer and fan performance correlations were developed (most notably, a two-parameter correlation that predicts the dimensionless heat transfer coefficients across 98% of the experimental work to within 20% relative RMS error). Finally, models were developed to describe the scaling of the heat transfer and mechanical power consumption in multi-fan heat sinks. These models were assessed against experimental results from two prototypes, and suggest that future integrated fan heat sink designs can achieve a 4x reduction in thermal resistance and 3x increase in coefficient of performance compared to current state-of-the-art air cooled heat sinks.
Download or read book Advances in Heat Transfer Enhancement written by Sujoy Kumar Saha and published by Springer. This book was released on 2016-04-23 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Brief addresses the phenomena of heat transfer enhancement. A companion edition in the SpringerBrief Subseries on Thermal Engineering and Applied Science to three other monographs including “Critical Heat Flux in Flow Boiling in Microchannels,” this volume is idea for professionals, researchers, and graduate students concerned with electronic cooling.
Download or read book Heat Transfer Enhancement in Plate and Fin Extended Surfaces written by Sujoy Kumar Saha and published by Springer. This book was released on 2019-06-24 with total page 145 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Brief deals with heat transfer and friction in plate and fin extended heat transfer enhancement surfaces. It examines Offset-Strip Fin (OSF), Enhancement Principle, Analytically Based Models for j and f vs. Re, Transition from Laminar to Turbulent Region, Correlations for j and f vs. Re, Use of OSF with Liquids, Effect of Percent Fin Offset, Effect of Burred Edges, Louver fin, heat transfer and friction correlations, flow structure in the louver fin array, analytical model for heat transfer and friction, convex louver fin, wavy fin, 3D corrugated fin, perforated fin, pin fins and wire mesh, types of vortex generators, metal foam fin, plain fin, packings, numerical simulation of various types of fins.
Download or read book Heat Transfer Enhancement of Microchannel Heat Sink Using Transcritical Carbon Dioxide as the Coolant written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Silicon Microchannel Heat Sinks written by Lian Zhang and published by Springer Science & Business Media. This book was released on 2013-03-14 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two-phase microchannel cooling is one of the most promising thermal-management technologies for future high-power IC chips. Understanding the boiling process and the two-phase-flow behavior in microchannels is the key to successful implementation of a microchannel heat sink. This book focuses on the phase-change phenomena and the heat transfer in sub-150 nm diameter silicon microchannels, with emphasis on thermal measurement and modeling, and the impact of small dimensions on two-phase flow regimes.
Download or read book Enhancement of Heat Transfer from Heat Sinks by Shrouding Under Uniform Heat Flux Condition written by Tai Hing Ngai and published by . This book was released on 1988 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Heat Transfer written by Younes Shabany and published by CRC Press. This book was released on 2009-12-17 with total page 526 pages. Available in PDF, EPUB and Kindle. Book excerpt: The continuing trend toward miniaturization and high power density electronics results in a growing interdependency between different fields of engineering. In particular, thermal management has become essential to the design and manufacturing of most electronic systems.Heat Transfer: Thermal Management of Electronics details how engineers can use
Download or read book Heat Transfer and Fluid Flow in Minichannels and Microchannels written by Satish Kandlikar and published by Elsevier. This book was released on 2006 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt: &Quot;This book explores flow through passages with hydraulic diameters from about 1 [mu]m to 3 mm, covering the range of minichannels and microchannels. Design equations along with solved examples and practice problems are also included to serve the needs of practicing engineers and students in a graduate course."--BOOK JACKET.
Download or read book Microfabricated Systems and MEMS VI written by Peter J. Hesketh and published by The Electrochemical Society. This book was released on 2002 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Heat Transfer Enhancement with Nanofluids written by Vincenzo Bianco and published by CRC Press. This book was released on 2015-04-01 with total page 473 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanofluids are gaining the attention of scientists and researchers around the world. This new category of heat transfer medium improves the thermal conductivity of fluid by suspending small solid particles within it and offers the possibility of increased heat transfer in a variety of applications. Bringing together expert contributions from
Download or read book Thermal Transport in Oblique Finned Micro Minichannels written by Yan Fan and published by Springer. This book was released on 2014-11-05 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The main aim of this book is to introduce and give an overview of a novel, easy, and highly effective heat transfer augmentation technique for single-phase micro/minichannel heat sink. The specific objectives of the volume are to: Introduce a novel planar oblique fin microchannel and cylindrical oblique fin minichannel heat sink design using passive heat transfer enhancement techniques Investigate the thermal transport in both planar and cylindrical oblique fin structures through numerical simulation and systematic experimental studies. Evaluate the feasibility of employing the proposed solution in cooling non-uniform heat fluxes and hotspot suppression Conduct the similarity analysis and parametric study to obtain empirical correlations to evaluate the total heat transfer rate of the oblique fin heat sink Investigate the flow mechanism and optimize the dimensions of cylindrical oblique fin heat sink Investigate the influence of edge effect on flow and temperature uniformity in these oblique fin channels.
Download or read book Integrated Interconnect Technologies for 3D Nanoelectronic Systems written by Muhannad S. Bakir and published by Artech House. This book was released on 2008-11-30 with total page 551 pages. Available in PDF, EPUB and Kindle. Book excerpt: This cutting-edge book on off-chip technologies puts the hottest breakthroughs in high-density compliant electrical interconnects, nanophotonics, and microfluidics at your fingertips, integrating the full range of mathematics, physics, and technology issues together in a single comprehensive source. You get full details on state-of-the-art I/O interconnects and packaging, including mechanically compliant I/O approaches, fabrication, and assembly, followed by the latest advances and applications in power delivery design, analysis, and modeling. The book explores interconnect structures, materials, and packages for achieving high-bandwidth off-chip electrical communication, including optical interconnects and chip-to-chip signaling approaches, and brings you up to speed on CMOS integrated optical devices, 3D integration, wafer stacking technology, and through-wafer interconnects.
Download or read book Principles of Enhanced Heat Transfer written by Ralph L. Webb and published by Wiley-Interscience. This book was released on 1994-03-28 with total page 584 pages. Available in PDF, EPUB and Kindle. Book excerpt: Indeed, today "second generation" enhancement concepts are routing in the automotive and refrigeration industries to obtain lower cost, smaller heat exchanger size, and higher energy efficiency in system operation. And the aerospace, process, and power generation industries are not far behind.
Download or read book Enhancement of Natural Convection Heat Transfer from Heat Sinks by Shrouding written by Peter Tien Lin Zing and published by . This book was released on 1987 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Numerical Validation of Cooling Performance of Phase Change Materials Integrated Into Heat Sinks for Electronics Cooling written by Shaima Mohamed Abu Ayyan and published by . This book was released on 2015 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study aims to analyze the cooling performance of phase change materials (PCMs) integrated into metallic heat sinks (HSs) both experimentally and numerically. For the experimental part of the study, a test setup has been constructed to test PCM integrated heat sinks. The heat sinks are prepared as metallic containments having fins with fixed inter-fin spacing. The volume between the heat sink fins is filled with PCM namely: a paraffin wax, salt hydrate-calcium chloride and milk-fat, then the whole system is sealed for testing under various heat loads at 4W, 6W, 8W and 10W. Four modes of operation are experimentally tested in this study: HS under natural convection, HS integrated with PCM under natural convection, HS under forced convection, and HS integrated with PCM under forced ventilation. The temperature of heat generating surface and the heat sink surface are monitored over time to evaluate the PCM thermal performance. From the results, the time lag and temperature drop in case of with PCM compared to without PCM shows the cooling effect of adding PCM under both natural and forced ventilation modes of heat removal. It found that inclusion of each of the three types of PCM into heat sinks with natural convection shows higher temperature drop (up-to 15 °C) in first 15 min of heating than inclusion of fan (forced convection) without PCM. However, the combination of both the fan ventilation and the PCM always maintain the lower temperature other three modes. This leads to conclusion that implementing a PCM in the heat sink will be very useful in thermal management of the electronic device and the application is more suitable under cyclic thermal loading conditions since in all cases the PCM completes melting in certain time and then shows a temperature rise. It is recommended to use forced convection combined with PCM filled in HS to increase the cooling effect while using PCM will be recommended for short time operation or cyclic operation such as switching operations where PCM can be regenerated to solid during off duty cycle to be ready for the next cycle of heat absorption. It is also recommended to use PCM integrated into a HS to provide a backup passive cooling support especially in case of failure of the fan system during operation as an additional safety cover. For the numerical part of the study, a three dimensional transient heat transfer numerical model using commercial ANSYS CFD software is developed and is validated against the experimental results. Next the numerical model is used to optimize the heat sink geometry, the PCM amount and the viii cooling-heating response in order to identify potential applications in electronic packaging in terms of temperature drop and charging-discharging cycle time. From parametric study, it is observed that a narrow melting point, not mixing of the PCM, good thermal conductivity, higher density, rectangular fin type and a reasonable package size are optimum for the temperature control of electronic devices employing heat sink with PCM.
Download or read book Enhancement of Air Jet Impingement Heat Transfer Using Pin Fin Heat Sinks written by Hani Ali El-Sheikh and published by . This book was released on 1999 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Development of Active Heat Transfer Enhancement Devices from Shape Memory Alloys in a Selective Laser Melting Process written by Mohd Shiraz Aris and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
