Optimal Design for Thermal Performance of a Heat Sink Integrated With Thermoelectric Cooler

2005 ◽  
Author(s):  
M. C. Wu ◽  
C. H. Peng ◽  
C. Y. Lee ◽  
C. J. Fang ◽  
Y. H. Hung
Keyword(s):  
Sensitivity Analysis ◽  
Optimal Design ◽  
Thermal Performance ◽  
Heat Sink ◽  
Optimization Technique ◽  
Empirical Method ◽  
Heat Sinks ◽  
Air Cooling ◽  
Thermoelectric Coolers ◽  
Semi Empirical

The demand for high execution speed and memory capacity for modern computers results in an increasing circuit density per unit chip and high power dissipation per unit volume. Consequently, traditional air cooling technology such as air-cooled heat sink is reaching the limits for electronic applications. Thermoelectric coolers are regarded as potential solutions for enhancing the performance of air-cooled heat sinks. In the present study, a semi-empirical method for exploring the thermal performance of a heat sink integrated with or without TEC has been successfully established. A concept of design of experiments (DOE) is applied, and a statistical method for sensitivity analysis of the influencing parameters is performed to determine the key factors that are critical to the design. By the statistical sensitivity analysis of ANOVA F-test for the temperature reduction (ΔTC−B) and COP of the TEC, the factor contributions of QP, Rext and I are 31.66%, 33.73%, 34.61% as well as 14.9%, 0%, 85.1%, respectively. By employing the gradient-based numerical optimization technique, a series of constrained optimal designs have been performed. Under the given constraints of COP≧2, the optimal value of ΔTC−B (3.3°C) is obtained with the corresponding Qp (31.99W) and Qte (16W). Comparisons between the results by the present optimal design and those obtained by the semi-empirical results have been made with a satisfactory agreement. The present optimal design shows that a heat sink integrated with TEC can extend the upper limits of thermal management for traditional air-cooled heat sinks.

Improving the Thermal Performance of a Forced Convection Air Cooled Solution: Part 1 — Modification of Heat Sink Assembly

2013 ◽  
Author(s):  
Saeed Ghalambor ◽  
John Edward Fernandes ◽  
Dereje Agonafer ◽  
Veerendra Mulay
Keyword(s):  
Pressure Distribution ◽  
Forced Convection ◽  
Thermal Performance ◽  
Heat Sink ◽  
Heat Sinks ◽  
Thermal Interface Material ◽  
Air Cooling ◽  
Interfacial Pressure ◽  
Interfacial Contact ◽  
Torque Analysis

Forced convection air cooling using heat sinks is one of the most prevalent methods in thermal management of microelectronic devices. Improving the performance of such a solution may involve minimizing the external thermal resistance (Rext) of the package. For a given heat sink design, this can be achieved by reducing the thermal interface material (TIM) thickness through promotion of a uniform interfacial pressure distribution between the device and heat sink. In this study, a dual-CPU rackmount server is considered and modifications to the heat sink assembly such as backplate thickness and bolting configuration are investigated to achieve the aforementioned improvements. A full-scale, simplified model of the motherboard is deployed in ANSYS Mechanical, with emphasis on non-linear contact analysis and torque analysis of spring screws, to determine the optimal design of the heat sink assembly. It is observed that improved interfacial contact and pressure distribution is achieved by increasing the number of screws (loading points) and positioning them as close to the contact area as possible. The numerical model is validated by comparison with experimental measurements within reasonable accuracy. Based on the results of numerical analysis, the heat sink assembly is modified and improvement over the base configuration is experimentally quantified through interfacial pressure measurement. The effect of improved interfacial contact on thermal performance of the solution is discussed.

A Semi-Empirically Thermal Optimization for Heat Sink/TEC Assemblies With Various External Thermal Resistances

2007 ◽  
Author(s):  
M. C. Wu ◽  
T. Y. Wu ◽  
J. T. Horng ◽  
S. F. Chang ◽  
P. L. Chen ◽  
...  
Keyword(s):  
Thermal Resistance ◽  
Thermal Performance ◽  
Network Models ◽  
Empirical Method ◽  
Heat Sinks ◽  
Performance Improvements ◽  
Design Variables ◽  
Fitting Method ◽  
Parametric Studies ◽  
Semi Empirical

An effective semi-empirical method that combines thermal network models and empirical correlations for exploring the thermal performance of heat sinks and HS/TEC assemblies under different external thermal resistances is successfully established. A series of parametric studies, including the effects of external thermal resistance, input current of TEC and pumping heat capacity, on thermal performance improvements of HS/TEC assemblies have been performed. The Response Surface Methodology (RSM) is applied to establish explicit models of the thermal performance of HS/TEC assemblies under various external thermal resistances in terms of the design variables through statistical fitting method. Furthermore, the numerical optimization results for HS/TEC assemblies under different constraints are obtained. With constrained optimal designs of HS/TEC assemblies, the HS/TEC assemblies can provide excellent thermal performance improvements on (1) the reduction of thermal resistance, (2) the enhancement of module heat loads and (3) the improvement of external thermal resistance.

Effect of Flow Bypass on the Performance of Longitudinal Fin Heat Sinks

1994 ◽  
Vol 116 (3) ◽  
pp. 206-211 ◽  
Author(s):  
R. A. Wirtz ◽  
Weiming Chen ◽  
Ronghua Zhou
Keyword(s):  
Heat Transfer ◽  
Forced Convection ◽  
Thermal Performance ◽  
Heat Sink ◽  
Design Guidelines ◽  
Heat Sinks ◽  
Air Cooling ◽  
Regular Array ◽  
Electronic Package ◽  
And Performance

Heat transfer experiments are reported on the thermal performance of longitudinal fin heat sinks attached to an electronic package which is part of a regular array of packages undergoing forced convection air cooling. The effect of coolant bypass on the performance of the heat sink is assessed and performance correlations for reduced heat transfer due to this effect are developed. These correlations are used to develop design guidelines for optimal performance.

“Heat Shield”—An Enhancement Device for an Unshrouded, Forced Convection Heat Sink

2006 ◽  
Vol 128 (2) ◽  
pp. 172-176 ◽  
Author(s):  
Suzana Prstic ◽  
Avram Bar-Cohen
Keyword(s):  
Pressure Drop ◽  
Thermal Performance ◽  
Heat Sink ◽  
Thin Sheet ◽  
Heat Sinks ◽  
Heat Shield ◽  
Air Cooling ◽  
Thermal Enhancement ◽  
Thin Sheet Metal ◽  
Forced Air

The inherent advantages of forced air cooling have led to the widespread use of fully and partially shrouded heat sinks for the thermal management of high power microprocessors. The superior thermal performance that is achievable in the fully shrouded configuration is accompanied by a significant pressure drop penalty. The concept introduced in the current study, employs a thin sheet-metal “heat shield,” placed around a partially shrouded heat sink, to channel the flow directly into the heat sink. A combined numerical and experimental study has shown that the use of this “heat shield” can substantially enhance heat sink thermal performance, in a channel geometry and air flow range typical of commercial chip packages; making it comparable to that of a fully shrouded heat sink, with a substantially lower pressure drop (∼50%). In addition, this thermal enhancement device can be easily retrofitted into existing systems; improving performance without major channel and/or fan modifications.

scholarly journals Study of Mini Channel Heat Sink with Different Internal Configuration

2020 ◽  
Vol 319 ◽  
pp. 02004
Author(s):  
Muhammad Akif Rahman ◽  
Md Badrath Tamam ◽  
Md Sadman Faruque ◽  
A.K.M. Monjur Morshed
Keyword(s):  
Nusselt Number ◽  
Thermal Performance ◽  
Heat Sink ◽  
Rectangular Channel ◽  
Three Dimensional ◽  
Heat Sinks ◽  
Maximum Temperature ◽  
Rectangular Channels ◽  
Flow Through ◽  
Internal Configuration

In this paper a numerical analysis of three-dimensional laminar flow through rectangular channel heat sinks of different geometric configuration is presented and a comparison of thermal performance among the heat sinks is discussed. Liquid water was used as coolant in the aluminum made heat sink with a glass cover above it. The aspect ratio (section height to width) of rectangular channels of the mini-channel heat sink was 0.33. A heat flux of 20 W/cm2 was continuously applied at the bottom of the channel with different inlet velocity for Reynold’s number ranging from 150 to 1044. Interconnectors and obstacles at different positions and numbers inside the channel were introduced in order to enhance the thermal performance. These modifications cause secondary flow between the parallel channels and the obstacles disrupt the boundary layer formation of the flow inside the channel which leads to the increase in heat transfer rate. Finally, Nusselt number, overall thermal resistance and maximum temperature of the heat sink were calculated to compare the performances of the modified heat sinks with the conventional mini channel heat sink and it was observed that the heat sink with both interconnectors and obstacles enhanced the thermal performance more significantly than other configurations. A maximum of 36% increase in Nusselt number was observed (for Re =1044).

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.

Understanding the Impact of Flow Bypass on the Thermal Performance of Air Cooled Heat Sinks

2014 ◽  
Author(s):  
Krishna Kota ◽  
Mohamed M. Awad
Keyword(s):  
Energy Conservation ◽  
Thermal Resistance ◽  
Thermal Performance ◽  
Heat Sink ◽  
Heat Sinks ◽  
Laminar Regime ◽  
Flow Energy ◽  
Factor Α ◽  
The Impact ◽  
Fundamental Mass

In this effort, theoretical modeling was employed to understand the impact of flow bypass on the thermal performance of air cooled heat sinks. Fundamental mass and flow energy conservation equations across a longitudinal fin heat sink configuration and the bypass region were applied and a generic parameter, referred as the Flow Bypass Factor (α), was identified from the theoretical solution that mathematically captures the effect of flow bypass as a quantifiable parameter on the junction-to-ambient thermal resistance of the heat sink. From the results obtained, it was found that, at least in the laminar regime, the impact of flow bypass on performance can be neglected for cases when the bypass gap is typically less than 5% of the fin height, and is almost linear at high relative bypass gaps (i.e., usually for bypass gaps that are more than 10–15% of the fin height). It was also found that the heat sink thermal resistance is more sensitive to small bypass gaps and the effect of flow bypass decreases with increasing bypass gap.

Capillary Pumped Loop Heat Spreader for Electronics Cooling

2001 ◽  
Author(s):  
Jaewon Chung ◽  
Costas P. Grigoropoulos ◽  
Ralph Greif
Keyword(s):  
Electronics Cooling ◽  
Cooling Capacity ◽  
Impinging Jets ◽  
Heat Sinks ◽  
Manufacturing Cost ◽  
Air Cooling ◽  
Capillary Pumped Loop ◽  
Heat Spreader ◽  
Vertical Orientation ◽  
Thermoelectric Coolers

Abstract As cooling requirements for electronic devices, e.g. computer processor units, power modules, etc. increase beyond the capabilities of air-cooling, interest has moved to several alternatives such as thermoelectric coolers, impinging jets and heat exchangers with phase change. Included among these, the capillary pumped loop is a very competitive cooling device, because of its performance reliability, no power requirements and low manufacturing cost. In this paper, a heat spreader employing capillary pumped loop principles was made of aluminum and copper and tested. The copper CPL heat spreader with heat sinks and fans on the condenser (86mm thick, 60mm wide, 181mm long) has demonstrated a cooling capacity of 640W at atmospheric pressure in the vertical orientation and maintains a difference between TIHE (temperature of the interface between heater and evaporator) and TAMB (ambient temperature) lower than 100°C.

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