“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.

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.

scholarly journals Thermal analysis and parametric optimization of plate fin heat sinks under forced air convection

2021 ◽  
pp. 81-81
Author(s):  
Zulfiqar Khattak ◽  
Hafiz Ali
Keyword(s):  
Pressure Drop ◽  
Thermal Resistance ◽  
Heat Sink ◽  
Heat Dissipation ◽  
Parametric Optimization ◽  
Heat Sinks ◽  
Air Velocity ◽  
Forced Air ◽  
Theoretical Results ◽  
Plate Type

Heat dissipation is becoming more and more challenging with the preface of new electronic components having staggering heat generation levels. Present day solutions should have optimized outcomes with reference to the heat sink scenarios. The experimental and theoretical results for plate type heat sink based on mathematical models have been presented in the first part of the paper. Then the parametric optimization (topology optimization) of plate type heat sink using Levenberg-Marquardt technique employed in the COMSOL Multiphysics? software is discussed. Thermal resistance of heat sink is taken as objective function against the variable length in a predefined range. Single as well as multi-parametric optimization of plate type heat sink is reported in the context of pressure drop and air velocity (Reynolds number) inside the tunnel. The results reported are compared with the numerical modeled data and experimental investigation to establish the conformity of results for applied usage. Mutual reimbursements of greater heat dissipation with minimum flow rates are confidently achievable through balanced, heat sink geometry as evident by the presented simulation outcome. About 12% enhancement in pressure drop and up to 51% improvement in thermal resistance is reported for the optimized plate fin heat sink as per data manifested.

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.

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.

Effect of channel and fin geometries on a trapeze plate-fin heat sink performance

2021 ◽  
pp. 095440892110059
Author(s):  
Özgür Özdilli ◽  
Seyfi Şevik
Keyword(s):  
Heat Transfer ◽  
Thermal Performance ◽  
Heat Sink ◽  
Channel Model ◽  
Rectangular Channel ◽  
Heat Sinks ◽  
Junction Temperature ◽  
Base Temperature ◽  
Thermal Enhancement ◽  
Standard Plate

This study aims to achieve a minimum base temperature (or junction temperature) and hence better thermal performance. Trapezoidal curved plate-fin heat sink with dolphin fins and rectangular channel (Model-1) and trapezoidal curved plate-fin heat sink with dolphin fins, cut corner, and rectangular channel (Model-2) were designed and compared with a standard plate-fin heat sink. The effects of fins on the airflow and heat transfer in designed plate-fin heat sinks have been investigated numerically. The numeric results show that the use of fins and small changes in geometry significantly improve the heat transfer rate. Outcomes of the study showed 44–51% and 57–62% convective heat transfer enhancement compared with a standard plate-fin heat sink, without any overall mass augmentation, in Model-1 and Model-2, respectively. The presence of dolphin fins reduces the thermal resistance by up to 30%, which contributes to the overall thermal enhancement of the designed plate-fin heat sinks. Simulation results show that increasing the fins in areas close to the heat source and reducing the non-working areas significantly influence the thermal performance of heat sinks. The results also show that the trapeze plate-fin heat sinks with the different channel-fin geometries are superior to the standard trapeze plate-fin heat sink in thermal performance.

Least-Volume Optimization of Finned Heat Sinks for Burn-in Air-Cooling Solutions

2003 ◽  
Author(s):  
Zhaojuan He ◽  
Patrick E. Phelan
Keyword(s):  
Heat Sink ◽  
Heat Dissipation ◽  
Past Research ◽  
Heat Sinks ◽  
Air Cooling ◽  
Electronic Packages ◽  
Pin Fin ◽  
Heat Spreaders ◽  
Forced Air ◽  
Innovative Techniques

With the development and increasing use of high-density components with their high power dissipation needs, electronic packages have required the investigation of innovative techniques for the efficient dissipation of heat. One prevalent method is the use of forced convection heat spreaders, called heat sinks, which are also widely used in Burn-In (BI) ovens. There are some contradictions remaining in recent research on modeling and Nusselt number correlations of heat sinks in forced air convection. This paper begins by reviewing past research for different finned heat sink geometries with and without bypass flow over the heat sinks. A new method called Least Volume Optimization is then proposed to analyze the thermal performance of finned heat sinks for BI air-cooling solutions. The analysis shows that the volumetric heat dissipation of a parallel plate fin heat sink is higher than that of a pin fin heat sink, based on an optimal fin geometry.

Heat Sink With Stacked Multi-Layer Porous Media

2014 ◽  
Author(s):  
Arun K. Karunanithi ◽  
Fatemeh Hassanipour
Keyword(s):  
Porous Media ◽  
Pressure Drop ◽  
Thermal Resistance ◽  
Thermal Performance ◽  
Heat Sink ◽  
Lower Pressure ◽  
Heat Sinks ◽  
Rectangular Channels ◽  
Mini Channels

Previous studies have shown that stacked multi-layer mini-channels heat sinks with square or circular channels have advantages over traditional single layered channels in terms of both pressure drop and thermal resistance. In this work, porous media is used in the multi-layered stacked mini-channels instead of square or rectangular channels and the effect of the same on pressure drop and thermal performance is studied. Porosity scaling is done between the layers of porous media and is compared with unscaled stacked multilayer channel. Porosity scaling allows the porosity to vary from one layer to the next layer and could result in a lower pressure drop and better thermal performance.

Thermal Optimal Design for Partially-Confined Compact Heat Sinks

2005 ◽  
Author(s):  
M. P. Wang ◽  
H. T. Chen ◽  
J. T. Horng ◽  
T. Y. Wu ◽  
P. L. Chen ◽  
...  
Keyword(s):  
Experimental Data ◽  
Pressure Drop ◽  
Thermal Resistance ◽  
Flow Velocity ◽  
Thermal Performance ◽  
Heat Sink ◽  
Heat Sinks ◽  
Optimal Designs ◽  
Inlet Flow ◽  
Design Factors

An effective method for predicting the optimal thermal performance of partially-confined compact heat sinks under multi-constraints of pressure drop and heat sink mass has been successfully developed. The design variables of PPF compact heat sinks include: heat sink fin and base material, thickness of heat sink base, heat flux, channel top bypass and inlet flow velocity. A total of 108 experimental cases for confined forced convection are designed by the Central Composite Design (CCD) method. According to the results in ANOVA, a sensitivity analysis for the design factors is performed. From the analysis, the effect of inlet flow velocity, which has the contribution percentage of 86.24%, dominates the thermal performance. The accuracies of the quadratic RSM models for both thermal resistance and pressure drop have been verified by comparing the predicted response values to the actual experimental data. The maximum deviations of thermal resistance and pressure drop are 9.41% and 7.20% respectively. The Response Surface Methodology is applied to establish analytical models of the thermal resistance and pressure drop constraints in terms of the key design factors with a CCD experimental design. By employing the Sequential Quadratic Programming technique, a series of constrained optimal designs can be efficiently performed. The numerical optimization results for four cases under different constraints are obtained, and the comparisons between these predicted optimal designs and those measured by the experimental data are made with a satisfactory agreement.

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