Thermo-Hydraulic Performance of Heat Sinks With Microchannel Embedded With Pin-fins

2021 ◽  
Author(s):  
Anas Alkhazaleh ◽  
Mohamed Younes El-Saghir Selim ◽  
Fadi Alnaimat ◽  
Bobby Mathew
Keyword(s):  
Pressure Drop ◽  
Thermal Resistance ◽  
Heat Sink ◽  
Reynolds Numbers ◽  
Sine Wave ◽  
Hydraulic Diameter ◽  
Heat Sinks ◽  
Microchannel Heat Sink ◽  
Pin Fins ◽  
The Cost

Abstract In this work, an investigation of the heat sink performance employing sinusoidal microchannels embedded with pin fins was conducted. The effect of the sine wave frequency, the pin fins’ diameter, and the hydraulic diameter of the microchannel are studied. The results are quantified in terms of thermal resistance and pressure drop. The study was done using Reynolds numbers varying from 250 to 2000. As Reynolds number increases, the heat sink’s thermal resistance decreased while the pressure drop increased accordingly for all scenarios. The sinusoidal microchannels showed better performance — lower thermal resistance — but with the cost of higher pressure drop compared to the straight microchannel heat sink. The heat sink’s performance was improved by increasing the frequency, diameter of pin fins, and hydraulic diameter; however, this reduction in thermal resistance was associated with an increase in pressure drop. The reduction in thermal resistance of the different configurations of the sinusoidal microchannels was between 17% and 69% compared to the straight microchannel heat sink.

Computational Fluid Dynamics Based Investigation of the Performance of Hybrid Heat Sinks

2021 ◽  
Author(s):  
Anas Alkhazaleh ◽  
Mohamed Younes El-Saghir Selim ◽  
Fadi Alnaimat ◽  
Bobby Mathew
Keyword(s):  
Reynolds Number ◽  
Pressure Drop ◽  
Thermal Resistance ◽  
Reynolds Numbers ◽  
Hydraulic Diameter ◽  
Heat Sinks ◽  
Geometrical Parameters ◽  
Microchannel Heat Sink ◽  
Liquid Cooling ◽  
Pin Fins

Abstract This article discusses the mathematical modeling of a straight microchannel heat sink, embedded with pin-fins, for purposes of liquid cooling of microelectronic chips. The influence of three different geometrical parameters, pin fins’ diameter, pitch, and hydraulic diameter, on the heat sinks performance is studied. The studies are performed for Reynolds numbers varying from 250 to 2000, and the results are quantified based on thermal resistance and pressure drop. The heat sinks embedded with pin fins have better performance in terms of thermal resistance but at the same time have higher pressure drop. Studies revealed that increasing the pin fins’ diameter, pitch, and hydraulic diameter have an influence on the thermal resistance; the thermal resistance is found to be decreasing with increasing these parameters for the same Reynolds number. For the cases studied, the reduction in thermal resistance of straight microchannels embedded with pin fins varied from 18% to 60% compared with that of traditional straight microchannels for different heat sinks configurations and Reynolds number. On the other hand, the pressure drop is increasing with an increase in pin fins’ diameter and pitch, while it is found to be decreasing with increasing the hydraulic diameter.

Optimization Under Uncertainty of Manifold Microchannel Heat Sinks

2012 ◽  
Author(s):  
Suchismita Sarangi ◽  
Karthik K. Bodla ◽  
Suresh V. Garimella ◽  
Jayathi Y. Murthy
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Pressure Drop ◽  
Transfer Coefficient ◽  
Heat Sink ◽  
Heat Sinks ◽  
Optimization Under Uncertainty ◽  
Microchannel Heat Sink ◽  
Probabilistic Optimization ◽  
Manifold Microchannel

Conventional microchannel heat sinks provide good heat dissipation capability but are associated with high pressure drop and corresponding pumping power. The use of a manifold system that distributes the flow into the microchannels through multiple, alternating inlet and outlet pairs is investigated here. This manifold arrangement greatly reduces the pressure drop incurred due to the smaller flow paths, while simultaneously increasing the heat transfer coefficient by tripping the thermal boundary layers. A three-dimensional numerical model is developed and validated, to study the effect of various geometric parameters on the performance of the manifold microchannel heat sink. Apart from a deterministic analysis, a probabilistic optimization study is also performed. In the presence of uncertainties in the geometric and operating parameters of the system, this probabilistic optimization approach yields an optimal design that is also robust and reliable. Uncertainty-based optimization also yields auxiliary information regarding local and global sensitivities and helps identify the input parameters to which outputs are most sensitive. This information can be used to design improved experiments targeted at the most sensitive inputs. Optimization under uncertainty also provides a quantitative estimate of the allowable uncertainty in input parameters for an acceptable uncertainty in the relevant output parameters. The optimal geometric design parameters with uncertainties that maximize heat transfer coefficient while minimizing pressure drop for fixed input conditions are identified for a manifold microchannel heat sink. A comparison between the deterministic and probabilistic optimization results is also presented.

Numerical Prediction of Thermal Performance of Water Cooled Multi-Stack Microchannel Heat Sink with Counterflow Arrangement

2011 ◽  
Vol 8 (1) ◽  
pp. 16-22 ◽  
Author(s):  
Pradeep Hegde ◽  
Mukesh Patil ◽  
K. N. Seetharamu
Keyword(s):  
Finite Element ◽  
Pressure Drop ◽  
Thermal Resistance ◽  
Thermal Performance ◽  
Heat Sink ◽  
Element Model ◽  
Channel Length ◽  
Computational Time ◽  
Microchannel Heat Sink ◽  
Method Performance

Thermal performance of a water cooled multistack microchannel heat sink with counterflow arrangement has been analyzed using the finite element method. Performance parameters such as thermal resistance, pressure drop, and pumping power are computed for a typical counterflow heat sink with different number of stacks. The temperature distribution in a typical multistack counterflow microchannel heat sink is obtained for different numbers of stacks and plotted along the channel length. A parametric study involving the effects of number of stacks and channel aspect ratio on thermal resistance and pressure drop of the heat sink is done. The finite element model developed for the analysis is simple and consumes less computational time.

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.

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.

scholarly journals Optimization of the thermal performance of multi-layer silicon microchannel heat sinks

2016 ◽  
Vol 20 (6) ◽  
pp. 2001-2013 ◽  
Author(s):  
Shanglong Xu ◽  
Yihao Wu ◽  
Qiyu Cai ◽  
Lili Yang ◽  
Yue Li
Keyword(s):  
Thermal Resistance ◽  
Thermal Performance ◽  
Heat Sink ◽  
Optimization Design ◽  
Heat Sinks ◽  
Structural Parameter ◽  
Microchannel Heat Sink ◽  
Total Thermal Resistance ◽  
Sqp Method ◽  
Resistance Network Model

The objective is to optimize the configuration sizes and thermal performance of a multilayer silicon microchannel heat sink by the thermal resistance network model. The effect of structural parameter on the thermal resistance is analyzed by numercal simulation. Taking the thermal resistance as an objective function, a nonlinear and multi-constrained optimization model are proposed for the silicon microchannel heat sink in electronic chips cooling. The sequential quadratic programming (SQP) method is used to do the optimization design of the configuration sizes of the microchannel. For the heat sink with the size of 20mm?20mm and the power of 400 W, the optimized microchannel number, layer, height and width are 40 and 2, 2.2mm and 0.2mm, respectively, and its corresponding total thermal resistance for whole microchannel heat sink is 0.0424 K/W.

Thermal Analysis and Experimental Validation of Laminar Heat Transfer and Pressure Drop in Serpentine Channel Heat Sinks for Electronic Cooling

2014 ◽  
Vol 136 (3) ◽  
Author(s):  
Xiaohong Hao ◽  
Bei Peng ◽  
Gongnan Xie ◽  
Yi Chen
Keyword(s):  
Pressure Drop ◽  
Thermal Resistance ◽  
Reynolds Numbers ◽  
Electronic Cooling ◽  
Heat Sinks ◽  
Total Thermal Resistance ◽  
Serpentine Channel ◽  
Resistance Network ◽  
Aspect Ratios ◽  
Resistance Network Model

In this paper, a thermal resistance network analytical model is proposed to investigate the thermal resistance and pressure drop in serpentine channel heat sinks with 180 deg bends. The total thermal resistance is obtained using a thermal resistance network model based on the equivalent thermal circuit method. Pressure drop is derived considering straight channel and bend loss because the bends interrupt the hydrodynamic boundary periodically. Considering the effects of laminar flow development and redevelopment, the bend loss coefficient is obtained as a function of the Reynolds number, aspect ratios, widths of fins, and turn clearances, through a three-regime correlation. The model is then experimentally validated by measuring the temperature and pressure characteristics of heat sinks with different Reynolds numbers and different geometric parameters. Finally, the temperature-rise and pressure distribution of the thermal fluid with Reynolds numbers of 500, 1000, and 1500 are examined utilizing this model.

Multi Layer Micro Pin-Fins Heat Sinks for Better Performance

2010 ◽  
Author(s):  
T. J. John ◽  
B. Mathew ◽  
H. Hegab
Keyword(s):  
Temperature Distribution ◽  
Thermal Resistance ◽  
Heat Sink ◽  
Single Layer ◽  
Heat Sinks ◽  
Substrate Thickness ◽  
Pin Fin ◽  
Micro Channels ◽  
Pin Fins ◽  
Overall Performance

This study numerically investigates the feasibility and advantages of using a multilayer pin-fin heat sink to increase the overall performance of the heat sink. For the purpose of determining overall performance of the pin-fin heat sink a figure of merit (FOM) term is introduced in this paper, which constituted of both the thermal resistance and the pumping power of the heat sink. Higher the FOM of a heat sink better is its overall performance. A computational fluid dynamics software CoventorWARE™ is used for the analysis of micro heat sink performance. A small portion of the entire heat sink is modeled in this study assuming repeatability towards both sides for the ease of analysis. The developed models consist of two sections, the substrate (silicon) and the fluid (water at 278K). A uniform heat flux is applied to the base of the heat sink. A single layer micro pin-fin heat sinks with same dimensions as of the multi layer heat sink was also modeled for the comparison purpose. Temperature distribution at five different locations from the inlet to the outlet section is also analyzed to study the temperature distribution over the heat sink. Circular pin-fins were used in both the multilayer and single layer micro heat sinks. Feasibility of using micro channels as the second layer was also investigated in this paper and it proved to have advantages over using pin-fin structures on both layers. A geometric optimization based on the substrate thickness of the second layer of the double layer heat sink showed that the substrate thickness of the second layer doesn’t have any effect on the overall thermal resistance of the heat sink.

Analysis of Pin-Fin Heat Sinks With an Unconventional Fin Profile

2013 ◽  
Author(s):  
Jose-Luis Gonzalez-Hernandez ◽  
Abel Hernandez-Guerrero ◽  
Carlos Rubio-Jimenez ◽  
Cuauhtemoc Rubio-Arana
Keyword(s):  
Wave Function ◽  
Pressure Drop ◽  
Thermal Resistance ◽  
Geometric Parameter ◽  
Entropy Generation ◽  
Heat Sink ◽  
Total Pressure ◽  
Heat Sinks ◽  
Pin Fin ◽  
Sinusoidal Function

In this work the performance of pin-fin heat sinks having an unconventional fin profile is compared with the use of cylindrical fins. The fin profile is a sinusoidal function and a staggered array is considered. The overall thermal resistance and total pressure drop are reported for the pin-fin heat sinks. The effect of using a wave function for the fin is studied for different number of complete waves along the height of the fins and a geometric parameter defined as the ratio of the higher to the lower radius of the fins is proposed. The study is carried out for two different inlet velocities, and for two different fin densities, corresponding to 5×5 and 7×7 arrays. An entropy generation analysis for each pin fin heat sink configuration is carried out and reported. The results of the present analysis reveal that the proposed geometry has an improvement as compared to the conventional heat sinks profiles when there is a high number of waves per fin. The effect of the geometric parameters defined in this study for the thermal and hydraulic performance is identified and discussed as well.

Experimental Investigation of Liquid Cooling Through Shallow Copperclad Cavities With Etched Pin-Fin Arrays

2018 ◽  
Author(s):  
Yin Lam ◽  
Nicole Okamoto ◽  
Younes Shabany ◽  
Sang-Joon John Lee
Keyword(s):  
Pressure Drop ◽  
Thermal Resistance ◽  
Surface Area ◽  
Flow Rate ◽  
Heat Sink ◽  
Heat Removal ◽  
Heat Sinks ◽  
Liquid Cooling ◽  
Pin Fin ◽  
Pin Fin Arrays

Heat removal is an increasing engineering challenge for higher-density packaging of circuit components. Microchannel heat sinks with liquid cooling have been investigated to take advantage of high surface-to-volume ratio and higher heat capacity of liquids relative to gases. This study experimentally investigated heat removal by liquid cooling through shallow copperclad cavities with staggered pin-fin arrays. Cavities with pin-fins were fabricated by chemical etching of a copperclad layer (nominally 105 μm thick) on a printed-circuit substrate (FR-4). The overall etched cavity was 30 mm wide, 40 mm long, and 0.1 mm deep. The pins were 1.1 mm in diameter and were distributed in a staggered arrangement. The cavity was sealed with a second copperclad substrate using an elastomer gasket. This assembly was then connected to a syringe pump delivery system. Deionized water was used as the working fluid, with volumetric flow rate up to 1.5 mL/min. The heat sink was subjected to a uniform heat flux of 5 W on the underside. Performance of the heat sink was evaluated in terms of pressure drop and the convection thermal resistance. Pressure drop across the heat sinks was less than 10 kPa, dominated by wall surface area rather than the small surface area contributed by cylindrical pins. At low flow rate, caloric thermal resistance dominated the overall thermal resistance of the heat sink. When compared to a microchannel without pins, the pin-fin microchannel reduced convective thermal resistance of the heat sink by approximately a factor of 4.

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