Trade-off Design of Extruded Heat Sinks Using Mathematical Optimization

2004 ◽  
Vol 126 (3) ◽  
pp. 333-341 ◽  
Author(s):  
D. J. de Kock ◽  
J. A. Visser
Keyword(s):  
Thermal Resistance ◽  
Heat Sink ◽  
Mathematical Optimization ◽  
Optimization Techniques ◽  
Heat Sinks ◽  
Trade Off ◽  
Pareto Optimal Set ◽  
Semi Empirical ◽  
Optimal Set ◽  
Heat Sink Design

Heat sink designers have to balance a number of conflicting parameters to maximize the performance of heat sinks. This multi-parameter problem lends itself naturally to mathematical optimization techniques. The paper illustrates how mathematical optimization techniques combined with a semi-empirical thermal simulation program can be used to construct a trade-off curve (Pareto-optimal set) between the heat sink mass and thermal resistance for a given heat sink configuration. This trade-off curve can be used by the engineer to decide on the optimal heat sink design that is the best compromise between heat sink mass and thermal resistance for the specific application under consideration.

Constructing a Trade-Off Surface for Extruded Heat Sinks Exposed to Forced Convection

2003 ◽  
Author(s):  
D. J. de Kock ◽  
J. A. Visser
Keyword(s):  
Pressure Drop ◽  
Forced Convection ◽  
Heat Sink ◽  
Optimization Techniques ◽  
Heat Sinks ◽  
Maximum Temperature ◽  
Design Criteria ◽  
Relative Importance ◽  
Trade Off ◽  
Optimum Heat

In modern electronic components power densities are being increased continuously while the size and weight decrease. The effective dissipating of the heat produced by these components has now become a major design problem. Ordinary heat sinks often used to dissipate this heat, can in many instances no longer be used. Heat sinks therefore need to be designed and optimized for specific applications. The design of these heat sinks requires a difficult trade-off between conflicting parameters, e.g. mass or material cost, maximum temperature and pressure drop. Since these parameters influence one another, optimum designs require the use of mathematical optimization techniques. In the case of heat sinks, the thermal engineer would typically like to optimize the design simultaneously for three design parameters. The parameters are maximum heat sink temperature, mass and pressure drop. In the formulation of such an optimization problem, where more than one design criterion is important, the engineer currently has to assign the relative importance of each design criteria before starting the optimization. A better approach is to perform a range of optimization problems where the relative importance of the design criteria is varied systematically to obtain a trade-off surface of optimum heat sinks. This surface can then be used to investigate the influence of the different design criteria on each other and to select the optimum heat sink for a specific application. In this study such a trade-off surface is created for an extruded heat sink exposed to forced convection. The constructing of this surface is obtained by combining a semi-empirical simulation program, QFin 3.0 with the DYNAMIC-Q optimization method.

Minimization of Heat Sink Mass Using CFD and Mathematical Optimization

1999 ◽  
Vol 121 (3) ◽  
pp. 143-147 ◽  
Author(s):  
K. J. Craig ◽  
D. J. de Kock ◽  
P. Gauche´
Keyword(s):  
Heat Source ◽  
Heat Sink ◽  
Mathematical Optimization ◽  
Optimization Techniques ◽  
Heat Sinks ◽  
Heat Sources ◽  
Cooling Fan ◽  
Design Variables ◽  
Multiparameter Problem ◽  
Heat Sink Temperature

This paper describes the use of CFD and mathematical optimization to minimise heat sink mass given a maximum allowable heat sink temperature, a constant cooling fan power and heat source. Heat sink designers have to consider a number of conflicting parameters. Heat transfer is influenced by, amongst others, heat sink properties (such as surface area), airflow bypass and the location of heat sources, whilst size and/or mass of the heat sink needs to be minimized. This multiparameter problem lends itself naturally to optimization techniques. In this study a commercial CFD code, STAR-CD, is linked to the DYNAMIC-Q method of Snyman. Five design variables are considered for three heat source cases. Optimal designs are obtained within six design iterations. The paper illustrates how mathematical optimization can be used to design compact heat sinks for different types of electronic enclosures.

Thermal Behaviors of Passively-Cooled Hybrid Fin Heat Sinks for Lightweight and High Performance Thermal Management

2015 ◽  
Author(s):  
Nico Setiawan Effendi ◽  
Kyoung Joon Kim
Keyword(s):  
Thermal Resistance ◽  
Heat Sink ◽  
High Performance ◽  
Heat Dissipation ◽  
Computational Study ◽  
Heat Sinks ◽  
Channel Diameter ◽  
Internal Channel ◽  
Study Results ◽  
Parametric Effects

A computational study is conducted to explore thermal performances of natural convection hybrid fin heat sinks (HF HSs). The proposed HF HSs are a hollow hybrid fin heat sink (HHF HS) and a solid hybrid fin heat sink (SHF HS). Parametric effects such as a fin spacing, an internal channel diameter, a heat dissipation on the performance of HF HSs are investigated by CFD analysis. Study results show that the thermal resistance of the HS increases while the mass-multiplied thermal resistance of the HS decreases associated with the increase of the channel diameter. The results also shows the thermal resistance of the SHF HS is 13% smaller, and the mass-multiplied thermal resistance of the HHF HS is 32% smaller compared with the pin fin heat sink (PF HS). These interesting results are mainly due to integrated effects of the mass-reduction, the surface area enhancement, and the heat pumping via the internal channel. Such better performances of HF HSs show the feasibility of alternatives to the conventional PF HS especially for passive cooling of LED lighting modules.

Influence of selected factors on parameters of a cooling system with a Peltier module and forced air flow

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Krzysztof Posobkiewicz ◽  
Krzysztof Górecki
Keyword(s):  
Thermal Resistance ◽  
Heat Sink ◽  
Cooling System ◽  
Heat Sinks ◽  
Cooling Power ◽  
Cooling Systems ◽  
Content Type ◽  
Peltier Module ◽  
Peltier Modules ◽  
Forced Air

Purpose The purpose of this study is to investigate the validation of the usefulness of cooling systems containing Peltier modules for cooling power devices based on measurements of the influence of selected factors on the value of thermal resistance of such a cooling system. Design/methodology/approach A cooling system containing a heat-sink, a Peltier module and a fan was built by the authors and the measurements of temperatures and thermal resistance in various supply conditions of the Peltier module and the fan were carried out and discussed. Findings Conclusions from the research carried out answer the question if the use of Peltier modules in active cooling systems provides any benefits comparing with cooling systems containing just passive heat-sinks or conventional active heat-sinks constructed of a heat-sink and a fan. Research limitations/implications The research carried out is the preliminary stage to asses if a compact thermal model of the investigated cooling system can be formulated. Originality/value In the paper, the original results of measurements and calculations of parameters of a cooling system containing a Peltier module and an active heat-sink are presented and discussed. An influence of power dissipated in the components of the cooling system on its efficiency is investigated.

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.

Thermal Analysis of Miniature Low Profile Heat Sinks With and Without Fins

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
V. Egan ◽  
P. A. Walsh ◽  
E. Walsh ◽  
R. Grimes
Keyword(s):  
Heat Transfer ◽  
Heat Sink ◽  
Volume Flow Rate ◽  
Electronic Devices ◽  
Heat Fluxes ◽  
Heat Sinks ◽  
Superior Performance ◽  
Low Profile ◽  
In Series ◽  
Heat Sink Design

Reliable and efficient cooling solutions for portable electronic devices are now at the forefront of research due to consumer demand for manufacturers to downscale existing technologies. To achieve this, the power consumed has to be dissipated over smaller areas resulting in elevated heat fluxes. With regard to cooling such devices, the most popular choice is to integrate a fan driven heat sink, which for portable electronic devices must have a low profile. This paper presents an experimental investigation into such low profile cooling solutions, which incorporate one of the smallest commercially available fans in series with two different heat sink designs. The first of these is the conventionally used finned heat sink design, which was specifically optimized and custom manufactured in the current study to complement the driving fan. While the second design proposed is a novel “finless” type heat sink suitable for use in low profile applications. Together the driving fan and heat sinks combined were constrained to have a total footprint area of 465 mm2 and a profile height of only 5 mm, making them ideal for use in portable electronics. The objective was to evaluate the performance of the proposed finless heat sink design against a conventional finned heat sink, and this was achieved by means of thermal resistance and overall heat transfer coefficient measurements. It was found that the proposed finless design proved to be the superior cooling solution when operating at low fan speeds, while at the maximum fan speed tested of 8000 rpm both provided similar performance. Particle image velocimetry measurements were used to detail the flow structures within each heat sink and highlighted methods, which could further optimize their performance. Also, these measurements along with corresponding global volume flow rate measurements were used to elucidate the enhanced heat transfer characteristics observed for the finless design. Overall, it is shown that the proposed finless type heat sink can provide superior performance compared with conventional finned designs when used in low profile applications. In addition a number of secondary benefits associated with such a design are highlighted including lower cost, lower mass, lower acoustics, and reduced fouling issues.

The Development of an Integrated Fan and Heat Sink Solution for Thermal Management in Low Profile Applications

2006 ◽  
Author(s):  
Ed Walsh ◽  
Ronan Grimes
Keyword(s):  
Heat Flux ◽  
Thermal Management ◽  
Heat Sink ◽  
Heat Sinks ◽  
Portable Electronics ◽  
Low Profile ◽  
Convection Cooling ◽  
New Methodologies ◽  
Heat Sink Design ◽  
Management Issues

The increasing heat flux densities from portable electronics are leading to new methodologies being implemented to provide thermal management within such devices. Many technologies are under development to transport heat within electronic equipment to allow it to be transported into the surroundings via conduction, natural convection and radiation. Few have considered the approach of implementing a forced convection cooling solution in such devices. This work addresses the potential of a low profile integrated fan and heat sink solution to electronics thermal management issues of the future, particularly focusing upon possible solutions in low profile portable electronics. We investigate two heat sink designs with mini channel features, applicable to low profile applications. The thermal performance of the heat sinks is seen to differ by approximately 40% and highlights the importance of efficient heat sink design at this scale.

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.

S-Shaped Pin-Fins for Enhancement of Overall Performance of the Pin-Fin Heat Sink

2010 ◽  
Author(s):  
T. J. John ◽  
B. Mathew ◽  
H. Hegab
Keyword(s):  
Reynolds Number ◽  
Thermal Resistance ◽  
Thermal Performance ◽  
Heat Sink ◽  
Heat Sinks ◽  
Uniform Heat Flux ◽  
Pumping Power ◽  
Pin Fin ◽  
Pin Fins ◽  
Overall Performance

In this paper the authors are studying the effect of introducing S-shaped pin-fin structures in a micro pin-fin heat sink to enhance the overall thermal performance of the heat sinks. For the purpose of evaluating the overall thermal performance of the heat sink a figure of merit (FOM) term comprising both thermal resistance and pumping power is introduced in this paper. An optimization study of the overall performance based on the pitch distance of the pin-fin structures both in the axial and the transverse direction, and based on the curvature at the ends of S-shape fins is also carried out in this paper. The value of the Reynolds number of liquid flow at the entrance of the heat sink is kept constant for the optimization purpose and the study is carried out over a range of Reynolds number from 50 to 500. All the optimization processes are carried out using computational fluid dynamics software CoventorWARE™. The models generated for the study consists of two sections, the substrate (silicon) and the fluid (water at 278K). The pin fins are 150 micrometers tall and the total structure is 500 micrometer thick and a uniform heat flux of 500KW is applied to the base of the model. The non dimensional thermal resistance and nondimensional pumping power calculated from the results is used in determining the FOM term. The study proved the superiority of the S-shaped pin-fin heat sinks over the conventional pin-fin heat sinks in terms of both FOM and flow distribution. S-shaped pin-fins with pointed tips provided the best performance compared to pin-fins with straight and circular tips.

Experiments on the Flow and Heat Transfer in Fine Pitch Parallel Plate Heat Sinks With Top Inlet Side Exit Flow

2007 ◽  
Author(s):  
Felipe E. Ortega-Gutierrez ◽  
Alfonso Ortega
Keyword(s):  
Thermal Resistance ◽  
Heat Sink ◽  
Parallel Plate ◽  
Ad Hoc ◽  
Loss Coefficient ◽  
Heat Sinks ◽  
Pressure Measurements ◽  
Total Thermal Resistance ◽  
Fine Pitch ◽  
Jet Nozzle

Detailed temperature and pressure measurements in high aspect ratio parallel plate fin heat sinks were made in a Top Inlet Side Exit (TISE) experiment configuration without top bypass flow. Air flow was supplied to the top of the heat sink using a rectangular jet nozzle with three different jet nozzle widths, Wj. The study covered five jet velocities and three different jet nozzle width to heat sink length ratios. Static pressure measurements were made along the spanwise centerline inside the heat sink and on the mounting plate outside the heat sink. The measurements were used to study the influence of the jet impinging on the top of the heat sink on the loss coefficient of the heat sink. It was found that the overall loss coefficient was dependent on Re, Wj, the fin spacing, b, and the jet nozzle width relative to the heat sink length, Wj/L. Temperature measurements were made to study the total thermal resistance with no base heat spreading. An ad hoc model was used to predict the total thermal resistance of the heat sink in this complicated flow. The model modifies the total cooled area of the fin as a function of jet width and heat sink geometry. Good agreement was found with the experimental data for the cases of Wj/L = 1.0 and 0.5. The model does not work well in the case of Wj/L = 0.25.

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