Heat Dissipation Performance of Micro-channel Heat Sink with Various Protrusion Designs

This research will focus on studying the effect of aperture size and shape of the micro-channel heat sink on heat dissipation performance for chip cooling. The micro-channel heat sink is considered to be a porous medium with fluid subject inter-facial convection. Derivation based on energy equation gives a set of governing partial differential equations describing the heat transfer through the micro-channels. Numerical simulation, including steady-state thermal analysis based on CFD software, is used to create a finite element solver to tackle the derived partial differential equations with properly defined boundary conditions related to temperature. After simulating three types of heat sinks with various protrusion designs including micro-channels fins, curly micro-channels fins, and Micro-pin fins, the result shows that the heat sink with the maximum contact area per unit volume will have the best heat dissipation performance, we will interpret the result by using the volume averaging theorem on the porous medium model of the heat sink.

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Unsteady Radiative Natural Convective MHD Nanofluid Flow Past a Porous Moving Vertical Plate with Heat Source/Sink

Molecules ◽

10.3390/molecules25040854 ◽

2020 ◽

Vol 25 (4) ◽

pp. 854 ◽

Cited By ~ 3

Author(s):

Talha Anwar ◽

Poom Kumam ◽

Zahir Shah ◽

Wiboonsak Watthayu ◽

Phatiphat Thounthong

Keyword(s):

Partial Differential Equations ◽

Differential Equations ◽

Heat Sink ◽

Vertical Plate ◽

Flow Direction ◽

Transverse Magnetic ◽

Thermal Profile ◽

Nanofluid Flow ◽

Partial Differential ◽

Source Sink

In this research article, we investigated a comprehensive analysis of time-dependent free convection electrically and thermally conducted water-based nanofluid flow containing Copper and Titanium oxide (Cu and TiO 2 ) past a moving porous vertical plate. A uniform transverse magnetic field is imposed perpendicular to the flow direction. Thermal radiation and heat sink terms are included in the energy equation. The governing equations of this flow consist of partial differential equations along with some initial and boundary conditions. The solution method of these flow interpreting equations comprised of two parts. Firstly, principal equations of flow are symmetrically transformed to a set of nonlinear coupled dimensionless partial differential equations using convenient dimensionless parameters. Secondly, the Laplace transformation technique is applied to those non-dimensional equations to get the close form exact solutions. The control of momentum and heat profile with respect to different associated parameters is analyzed thoroughly with the help of graphs. Fluid accelerates with increasing Grashof number (Gr) and porosity parameter (K), while increasing values of heat sink parameter (Q) and Prandtl number (Pr) drop the thermal profile. Moreover, velocity and thermal profile comparison for Cu and TiO 2 -based nanofluids is graphed.

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Entropy Generation Analysis in Nonlinear Convection Flow of Thermally Stratified Fluid in Saturated Porous Medium With Convective Boundary Condition

Journal of Heat Transfer ◽

10.1115/1.4036332 ◽

2017 ◽

Vol 139 (9) ◽

Cited By ~ 8

Author(s):

B. Vasu ◽

Ch. RamReddy ◽

P. V. S. N. Murthy ◽

Rama Subba Reddy Gorla

Keyword(s):

Boundary Condition ◽

Porous Medium ◽

Partial Differential Equations ◽

Differential Equations ◽

Entropy Generation ◽

Entropy Generation Rate ◽

Local Similarity ◽

Surface Boundary ◽

Thermal Dispersion ◽

Partial Differential

This article emphasizes the significance of entropy generation analysis and nonlinear temperature density relation on thermally stratified viscous fluid flow over a vertical plate embedded in a porous medium with a thermal dispersion effect. In addition, the convective surface boundary condition is taken into an account. By using the suitable transformations, the governing flow equations in dimensional form are converted into set of nondimensional partial differential equations. Then the local similarity and nonsimilarity procedures are applied to transform the set of nondimensional partial differential equations into set of ordinary differential equations and then the resulting system of equations are solved by Chebyshev spectral collocation method along with the successive linearization. The effect of pertinent parameters, namely, Biot number, mixed convection parameter, and thermal dispersion on velocity, temperature, entropy generation rate, and heat transfer rate are displayed graphically and the salient features are explored in detail.

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EFFECT OF CHEMICAL REACTION AND THERMAL RADIATION ON AXISYMMETRIC MHD FLOW OF JEFFREY NANOFLUID THROUGH A CILIATED CHANNEL FILLED WITH POROUS MEDIUM

Biomedical Engineering Applications Basis and Communications ◽

10.4015/s1016237221500253 ◽

2021 ◽

pp. 2150025

Author(s):

Sidra Shaheen ◽

Khadija Maqbool ◽

Farah Gul ◽

Ayesha Sohail

Keyword(s):

Magnetic Field ◽

Drug Delivery ◽

Porous Medium ◽

Partial Differential Equations ◽

Differential Equations ◽

Thermal Radiation ◽

Chemical Reaction ◽

Partial Differential ◽

Radiation Chemical ◽

Jeffrey Nanofluid

To prevent the respiratory diseases in an air ways, a defense mechanism based on mucus transport by the moving cilia plays an important role. The mucus transport is affected by the thermal radiation, chemical reaction that changes the physics of fluid due to nanoparticles and thickness of mucus, also different problems in respiratory tract may occur due to the mucus efficacy. In this study, it is observed that the mucus transport can be controlled by the magnetic field that is produced by the drug delivery of nanoparticles, thermal radiation due to temperature difference, porous medium due to respiratory infection, and diffusion of the nanoparticles (chemical reaction) due to the magnetic drug delivery. In this model, flow of Jeffrey nanofluid through the ciliated tube resembles with the mucus flow in a wind pipe. The movement of the mucus is observed by the momentum, energy and concentration equation in the presence of body forces due to magnetic field, heat source due to radiation, Darcy’s resistance due to infection and chemical reaction due to the concentration of nanoparticles. Mathematical model of this study forms a complex system of partial differential equations under the low Reynolds number and long wavelength approximation. The nonlinear set of partial differential equations is solved by the Homotopy perturbation method and software “Mathematica,” results are found for velocity, temperature and concentration profiles and concluded that the mucus flow decelerates due to magnetic field produced by the drug delivery of the nanoparticles but accelerates due to the viscoelastic parameter of Jeffrey fluid and Darcy’s resistance parameter due to infection. The heat transfer rate in the mucus flow rises by increasing the random motion and reduces by the radiation and energy loss. The diffusion of the nanoparticles in the mucus rises by the growing values of thermophoresis and chemical reaction parameter and reduces by the growing values of viscoelastic and Brownian motion parameter.

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Integral Micro-Channel Packages for Enhanced Thermal Performance

Volume 10: Heat Transfer, Fluid Flows, and Thermal Systems, Parts A, B, and C ◽

10.1115/imece2008-66423 ◽

2008 ◽

Cited By ~ 1

Author(s):

Stephen A. Solovitz ◽

Thomas E. Conder

Keyword(s):

Thermal Performance ◽

Heat Sink ◽

Impinging Jets ◽

Operating Conditions ◽

Micro Channel ◽

Mechanical Assembly ◽

Package Design ◽

Micro Channels ◽

Pin Fins ◽

Convective Thermal

Modern advancements in transistor technology have pushed thermal dissipations from power electronics near the edge of the capability of single-phase micro-channel designs. To alleviate this problem, researchers have begun investigating enhancements to these designs, using methods such as pin fins, turbulators, and impinging jets. These techniques can potentially enhance the convective thermal performance by a factor of 2 to 3, although they do incur a similar magnitude pressure penalty. However, because of the requirements of electrical isolation and mechanical assembly, much of this benefit is tempered, as the convective thermal resistance is only a small fraction of the total resistance. This limitation can be removed through the use of an integral package design where the heat sink passages are fashioned in the electrical stack, which can reduce the conductive resistance until convective enhancements are significant again. These methods include fabrication of micro-channels directly into the active metal braze substrate and potentially even the electrical insulation layer. Thus, while a traditional, non-integral design only experiences a 5% overall benefit when the convective resistance is reduced by 50%, an integral package can have a 20 to 30% improvement for the same enhancement. To examine this capability, a series of computational fluid dynamics studies were conducted to study the performance of several integral micro-channel heat sink configurations. These simulations determined the response for a range of coolants, flowrates, device power dissipations, and operating conditions. These results will serve as a baseline for further development of enhanced, integral micro-channel designs.

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Numerical Examination of Thermophysical Properties of Cobalt Ferroparticles over a Wavy Surface Saturated in Non-Darcian Porous Medium

Journal of Non-Equilibrium Thermodynamics ◽

10.1515/jnet-2019-0019 ◽

2020 ◽

Vol 45 (2) ◽

pp. 109-120

Author(s):

Irfan Mustafa ◽

Abuzar Ghaffari ◽

Tariq Javed ◽

Javeria Nawaz Abbasi

Keyword(s):

Porous Medium ◽

Nusselt Number ◽

Partial Differential Equations ◽

Differential Equations ◽

Magnetic Parameter ◽

Volume Fraction ◽

Wavy Surface ◽

Partial Differential ◽

Darcy Model ◽

The Impact

AbstractIn this study, the effect of magnetic field on an incompressible ferrofluid flow along a vertical wavy surface saturated in a porous medium is investigated. Ferrofluid is made by incorporating magnetic particles, in this case cobalt, at the nanoscale level into a base fluid. For the study of porous medium two well-known models, namely, Darcy and non-Darcy, are used. The mathematical model in terms of governing partial differential equations which are based on conservation laws in mechanics according to the assumption is developed, and this model is converted into a dimensionless form by suitable transformations. Due to the complex non-linear partial differential equations, the numerical solution is calculated by using an implicit finite difference scheme. The impact of involved parameters, namely, magnetic parameter, nanoparticle volume fraction parameter, the amplitude of the wavy surface, and the Grashof number, on Nusselt and average Nusselt numbers are studied through graphs and tables.The results show that for large values of the magnetic parameter, both the Nusselt number and the average Nusselt number decrease in ferrofluid flow. The value of the Nusselt number in the Darcy model is higher than the value of the Nusselt number in the non-Darcy model.

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Evaluation and Optimization of a Cross-Rib Micro-Channel Heat Sink

Micromachines ◽

10.3390/mi13010132 ◽

2022 ◽

Vol 13 (1) ◽

pp. 132

Author(s):

Haiying Chen ◽

Chuan Chen ◽

Yunyan Zhou ◽

Chenglin Yang ◽

Gang Song ◽

...

Keyword(s):

Pressure Drop ◽

Aspect Ratio ◽

Heat Sink ◽

Heat Dissipation ◽

Junction Temperature ◽

Micro Channel ◽

Test Chip ◽

Thermal Test ◽

Micro Channels ◽

The Cross

This article presents a novel cross-rib micro-channel (MC-CR) heat sink to make fluid self-rotate. For a thermal test chip (TTC) with 100 w/cm2, the cross-ribs micro-channel were compared with the rectangular (MC-R) and horizontal rib micro-channel (MC-HR) heat sinks. The results show that, with the cross-rib micro-channel, the junction temperature of the thermal test chip was 336.49 K, and the pressure drop was 22 kPa. Compared with the rectangular and horizontal ribs heat sink, the cross-rib micro-channel had improvements of 28.6% and 14.3% in cooling capability, but the pressure drop increased by 10.7-fold and 5.5-fold, respectively. Then, the effects of the aspect ratio (λ) of micro-channel in different flow rates were studied. It was found that the aspect ratio and cooling performance were non-linear. To reduce the pressure drop, the inclination (α) and spacing (S) of the cross-ribs were optimized. When α = 30°, S = 0.1 mm, and λ = 4, the pressure drop was reduced from 22 kPa to 4.5 kPa. In addition, the heat dissipation performance of the rectangular, staggered fin (MC-SF), staggered rib (MC-SR) and cross-rib micro-channels were analyzed in the condition of the same pressure drop, MC-CR still has superior heat dissipation performance.

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Impact of Channel Geometries and Flow Patterns On Micro-Channel Heat Sink Performance

International Journal of Innovative Technology and Exploring Engineering - Special Issue ◽

10.35940/ijitee.k1336.0981119 ◽

2019 ◽

Vol 8 (11) ◽

pp. 331-336

Keyword(s):

Heat Transfer ◽

Heat Sink ◽

Heat Dissipation ◽

Volume Ratio ◽

Nucleate Boiling ◽

Flow Patterns ◽

Micro Channel ◽

Micro Channels ◽

Extended Surface ◽

Vapour Quality

Demand for greater capability of electronic devices in very small volume for compactness has affected huge augmentations in heat indulgence at all stages of device, electronic wrapping, test section and system. Latest cooling systems are hence needed to eliminate the released heat while maintaining compactness of the device. The micro-channel heat sink (MCHS) is ideal for this situation as it consists of channels of micron size which offers an extended surface area to volume ratio of approximately 15.294 m2 / m3 compared to 650 m2 / m3 for a typical heat compact exchanger. A comprehensive review has been done for consequence of heat flux (qo ), mass flux (G), vapour quality (x) and channel geometries at flow patterns and heat dissipation of MCHS. The study show that to increase the rate of heat transfer by using different channel geometries like converging-diverging, segmented etc. compared to conventional rectangular micro-channels has given better cooling effect The Flow patterns like bubbly, slug flow are associated with nucleate boiling dominated in low vapour quality and annular flow also given the significant effect on heat transfer in higher vapour quality region

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