Thermal Characteristics of a Synthetic Jet Integrated Heat Sink Design for Air-Cooled Electronics

2009 ◽  
Author(s):  
Yogen Utturkar ◽  
Mehmet Arik ◽  
Tunc Icoz
Keyword(s):  
Heat Sink ◽  
Low Cost ◽  
Thermal Characteristics ◽  
Heat Removal ◽  
Synthetic Jet ◽  
Air Cooling ◽  
Air Jets ◽  
Trade Offs ◽  
Thermal Solution ◽  
Near Term

Thermal management is currently one of the key limitations in the design of electronic systems. Parallel to the advancements in the electronics industry and increase in power dissipation the development of effective, low-cost, compact heat removal solutions become extremely critical to ensure a failsafe and reliable operation. While liquid cooling is poised to provide the cooling capability for next generation electronics, its use in present-day products is less prevalent due to risks associated with condensation, leakage, and pumping power. Consequently, air-cooling strategies still continue to vie for near-term cooling needs in the electronic industry. In cohort with these trends, an advanced air-cooling solution in form of a synthetic jet assisted heat sink has been investigated in the present study. The study focuses on key design aspect of the heat sink fin design, synthetic jet design and characterization, and the interaction of unsteady air jets with the heat sink fins. Numerical simulations are employed to investigate 3D unsteady flow dynamics and experimental setup is designed and built for validation. The paper systematically presents the design trade-offs associated with the number of jets in the thermal solution and the jet driving conditions (voltage and frequency), in terms of the thermal performance and the cost. Overall, the synthetic jet integrated heat sink has demonstrably been shown to dissipate up to 4.7 times better than conventional natural convection heat sink with a COP value of greater than 40 within a volume of 25 in3.

Cooling Performance Evaluation of Synthetic Jet Based Thermal Solution Module

2015 ◽  
Vol 7 (3) ◽  
Author(s):  
Ahmad Jalilvand ◽  
Masataka Mochizuki ◽  
Yuji Saito ◽  
Yoji Kawahara ◽  
Randeep Singh ◽  
...  
Keyword(s):  
Thermal Resistance ◽  
Heat Pipe ◽  
Heat Sink ◽  
Electronic Devices ◽  
Heat Removal ◽  
Synthetic Jet ◽  
Air Jet ◽  
Convective Thermal ◽  
Thermal Solution ◽  
Pipe Heat

The convective thermal resistance which represents the heat removal from the heat sink surface of a heat pipe/heat sink module to mean coolant flow temperature is often a dominant contributor to the overall thermal resistance of a heat pipe/heat sink module or remote heat exchange (RHE). RHE is a thermal solution module composed of a heat spreader, thin flattened heat pipe with low profile heat sink which is widely used for the thermal management of compact portable electronic devices. Minimizing the convective thermal resistance at the heat sink of RHE as well as thickness reduction is often an important objective for the thermal designers. Recently, an alternate air mover system which operates based on piezoelectricity is developed. This device is called dual cooling jet (DCJ) in short which can be fabricated with very small thickness down to 1.0 mm. Thin DCJ as a synthetic jet generates air jet with more than 7 m/s air flow velocity which is promising for the increasing demands of thinner next generation portable electronic devices. DCJ is a promising device to dissipate the heat from the heat sink of a RHE. In this work, the performance of RHE is evaluated when heat is dissipated from its heat sink by DCJ. The results are compared with conventional rotary fan. The results show that more than 12 W of heat can be dissipated by DCJ which can easily compete with some commercialized rotary mini blowers while having much smaller thickness. Various configuration of heat sink–DCJ combinations as well as size and shape of both heat sink and DCJ are tested and based on thermal resistance data, cooling effectiveness of DCJ is studied.

Characterization of Light Weight Heat Sink Materials for Thermal Management of Electronics

2007 ◽  
Author(s):  
Tunc Icoz ◽  
Mehmet Arik ◽  
John T. Dardis
Keyword(s):  
Thermal Management ◽  
Heat Sink ◽  
High Efficiency ◽  
Computational Study ◽  
Heat Sinks ◽  
Advanced Materials ◽  
Air Cooling ◽  
Thermal Management Of Electronics ◽  
Thermal Solution

Thermal management of electronics is a critical part of maintaining high efficiency and reliability. Adequate cooling must be balanced with weight and volumetric requirements, especially for passive air-cooling solutions in electronics applications where space and weight are at a premium. It should be noted that there are systems where thermal solution takes more than 95% of the total weight of the system. Therefore, it is necessary to investigate and utilize advanced materials to design low weight and compact systems. Many of the advanced materials have anisotropic thermal properties and their performances depend strongly on taking advantage of superior properties in the desired directions. Therefore, control of thermal conductivity plays an important role in utilization of such materials for cooling applications. Because of the complexity introduced by anisotropic properties, thermal performances of advanced materials are yet to be fully understood. Present study is an experimental and computational study on characterization of thermal performances of advanced materials for heat sink applications. Numerical simulations and experiments are performed to characterize thermal performances of four different materials. An estimated weight savings in excess of 75% with lightweight materials are observed compared to the traditionally used heat sinks.

scholarly journals The Impact of Environmental Factors on the Thermal Characteristic of a Lithium–ion Battery

Batteries ◽  
2020 ◽  
Vol 6 (1) ◽  
pp. 3 ◽  
Author(s):  
Gerd Liebig ◽  
Ulf Kirstein ◽  
Stefan Geißendörfer ◽  
Frank Schuldt ◽  
Carsten Agert
Keyword(s):  
Lithium Ion Battery ◽  
Thermal Characteristic ◽  
Thermal Characteristics ◽  
Heat Removal ◽  
Lithium Ion ◽  
Air Cooling ◽  
Heat Rejection ◽  
Study Results ◽  
Electrochemical Model ◽  
The Impact

To draw reliable conclusions about the thermal characteristic of or a preferential cooling strategy for a lithium–ion battery, the correct set of thermal input parameters and a detailed battery layout is crucial. In our previous work, an electrochemical model for a commercially-available, 40 Ah prismatic lithium–ion battery was validated under heuristic temperature dependence. In this work the validated electrochemical model is coupled to a spatially resolved, three dimensional (3D), thermal model of the same battery to evaluate the thermal characteristics, i.e., thermal barriers and preferential heat rejection patterns, within common environment layouts. We discuss to which extent the knowledge of the batteries’ interior layout can be constructively used for the design of an exterior battery thermal management. It is found from the study results that: (1) Increasing the current rate without considering an increased heat removal flux at natural convection at higher temperatures will lead to increased model deviations; (2) Centralized fan air-cooling within a climate chamber in a multi cell test arrangement can lead to significantly different thermal characteristics at each battery cell; (3) Increasing the interfacial surface area, at which preferential battery interior and exterior heat rejection match, can significantly lower the temperature rise and inhomogeneity within the electrode stack and increase the batteries’ lifespan.

Thermal Design Criteria for Extraordinary Performance of Devices Cooled by Microchannel Heat Sink

2010 ◽  
Vol 2 (4) ◽  
Author(s):  
Dylan Farnam ◽  
Bahgat Sammakia ◽  
Kanad Ghose
Keyword(s):  
Contact Area ◽  
Heat Sink ◽  
Heat Removal ◽  
Thermal Design ◽  
Heat Sinks ◽  
Design Criteria ◽  
Microchannel Heat Sink ◽  
Device Architecture ◽  
Microchannel Heat Sinks ◽  
Thermal Solution

Increasing power dissipation in microprocessors and other devices is leading to the consideration of more capable thermal solutions than the traditional air-cooled fin heat sinks. Microchannel heat sinks (MHSs) are promising candidates for long-term thermal solution given their simplicity, performance, and the development of MHS-compatible 3D device architecture. As the traditional methods of cooling generally have uniform heat removal on the contact area with the device, thermal consequences of design have traditionally been considered only after the layout of components on a device is finalized in accordance with connection and other criteria. Unlike traditional cooling solutions, however, microchannel heat sinks provide highly nonuniform heat removal on the contact area with the device. This feature is of utmost importance and can actually be used quite advantageously, if considered during the design phase of a device. In this study, simple thermal design criteria governing the general placement of components on devices to be cooled by microchannel heat sink are developed and presented. These thermal criteria are not meant to supersede connection and other important design criteria but are intended as a necessary and valuable supplement. Full-scale numerical simulations of a device with a realistic power map cooled by microchannel heat sink prove the effectiveness of the criteria, showing large reduction in maximum operating temperature and harmful temperature gradients. The simulations further show that the device and microchannel heat sink can dissipate a comparatively high amount of power, with little thermal danger, when design considers the criteria developed herein.

Modeling Thermoelectric Device Enhancement of Heat Sink Performance

2007 ◽  
Author(s):  
Richard I. Roser ◽  
Robert M. Smythe ◽  
Malkiat Singh
Keyword(s):  
Thermal Resistance ◽  
Thermoelectric Material ◽  
Heat Sink ◽  
Graphical Representation ◽  
Heat Removal ◽  
Effect Of Temperature ◽  
Thermoelectric Device ◽  
Air Cooling ◽  
Material Parameters ◽  
Removal Capacity

Increased power density is straining the ability of air-cooled heat sink technologies to provide adequate cooling for heat-generating components. Several technologies are under investigation as replacements for air-cooling. Under specific conditions, a well-selected thermoelectric device [TED] can act as an enhancement to a heat sink’s heat removal capacity or allow it to achieve lower temperatures. Such improvements to heat sink performance using a thermoelectric device are possible without increasing airflow or heat sink dimensions. Proper sizing of this kind of optimized thermoelectric system involves consideration of multiple conditions, including the amount of heat being generated, the temperatures involved (typically, target case temperature and expected ambient temperature), and available voltage and current. Although thermoelectric devices are often thought of as inefficient, with Coefficients of Performance [COP] of less than 1, a well-selected TED can have a COP of much greater than 10. Existing methods for thermoelectric optimization, for the sake of simplicity, often ignore the thermal resistance of the heat sink or ignore the effect of temperature dependence of the thermoelectric material parameters of resistivity, thermal conductivity, and thermopower. To correctly include these factors in the design of the TED, a methodology has been developed to determine an optimum device while simultaneously considering the input parameters of θCA (case to ambient thermal resistance), heat load, target cooling temperatures, and available DC power. The method is iterative, involving the use of given input conditions to yield an estimate for expected final temperature conditions, which are used to produce an initial estimate of the thermoelectric material parameters, which in turn are used to calculate the optimized device. The performance of this device is calculated to determine a new estimate for temperatures and material parameters. The process is repeated until convergence occurs for the device design. The methodology can also demonstrate the performance benefits of integrating a TED into an existing conventional fan/sink system, and also describes conditions that are unsuitable for the use of TED’s. Graphical representation of the information can be readily generated as an aid to design.

Assessing Capabilities and Limitations of Air- and Liquid-Cooling for Low Profile Servers

2005 ◽  
Author(s):  
Albert Chan ◽  
Jie Wei
Keyword(s):  
Case Studies ◽  
Low Cost ◽  
Air Flow ◽  
Heat Removal ◽  
Air Cooling ◽  
Liquid Cooling ◽  
Widespread Application ◽  
Low Profile ◽  
Flow Through ◽  
Manufacturing Techniques

As microprocessor power exceeds 100W, adequate heat removal by convective air-flow through a heatsink increasingly becomes more challenging. This is especially true for low-profile servers with very limited volume for air-flow. It is therefore useful to have an idea of the limitations of air-cooling for such servers. In this paper, three case studies serve to illustrate the capability of typical air-cooled solutions for low-profile servers. These studies show the inherent limitations of air-cooled solutions for volume-constrained computer systems. Liquid-cooling has been used in cooling mainframe processors packaged in MCM format. Its use in low-cost servers is extremely limited. This paper will deal with issues that hinder widespread application of liquid-cooling in commercial servers. The most important issue is cost, followed by lack of commodity components suitable for liquid-cooled systems. One method to reduce cost is to use fabricate the cold plate using heatsink manufacturing techniques. Case studies are presented to show liquid-cooling with these lower cost cold plates can provide performance that exceeds air-cooling solutions. Finally, suggestions are offered for facilitating the introduction of liquid-cooling systems for future low-profile servers.   This paper was also originally published as part of the Proceedings of the ASME 2005 Heat Transfer Summer Conference.

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