Graphene nanoplatelets nanofluids thermal and hydrodynamic performance on integral fin heat sink

2017 ◽  
Vol 107 ◽  
pp. 995-1001 ◽  
Author(s):  
Waqas Arshad ◽  
Hafiz Muhammad Ali
Keyword(s):  
Heat Sink ◽  
Graphene Nanoplatelets ◽  
Hydrodynamic Performance

THERMAL AND HYDRODYNAMIC PERFORMANCE OF A MICROCHANNEL HEAT SINK COOLED WITH CARBON NANOTUBES NANOFLUID

2016 ◽  
Vol 78 (10-2) ◽  
Author(s):  
Nik Ahmad Faiz Nik Mazlam ◽  
Normah Mohd-Ghazali ◽  
Thierry Mare ◽  
Patrice Estelle ◽  
Salma Halelfadl
Keyword(s):  
Thermal Resistance ◽  
Heat Sink ◽  
Operating Temperature ◽  
Heat Removal ◽  
Hydrodynamic Performance ◽  
Spherical Particles ◽  
Microchannel Heat Sink ◽  
Pumping Power ◽  
Rectangular Microchannel ◽  
Aspect Ratios

The microchannel heat sink (MCHS) has been established as an effective heat removal system in electronic chip packaging. With increasing power demand, research has advanced beyond the conventional coolants of air and water towards nanofluids with their enhanced heat transfer capabilities. This research had been carried out on the optimization of the thermal and hydrodynamic performance of a rectangular microchannel heat sink (MCHS) cooled with carbon nanotube (CNT) nanofluid, a coolant that has recently been discovered with improved thermal conductivity. Unlike the common nanofluids with spherical particles, nanotubes generally come in cylindrical structure characterized with different aspect ratios. A volume concentration of 0.1% of the CNT nanofluid is used here; the nanotubes have an average diameter and length of 9.2 nm and 1.5 mm respectively. The nanofluid has a density of 1800 kg/m3 with carbon purity 90% by weight having lignin as the surfactant. The approach used for the optimization process is based on the thermal resistance model and it is analyzed by using the non-dominated sorting multi-objective genetic algorithm. Optimized outcomes include the channel aspect ratio and the channel wall ratio at the optimal values of thermal resistance and pumping power. The optimized results show that, at high operating temperature of 40°C the use of CNT nanofluid reduces the total thermal resistance by 3% compared to at 20°C and consequently improve the thermal performance of the fluid. In terms of the hydrodynamic performance, the pumping power is also being reduced significantly by 35% at 40°C compared to the lower operating temperature.  

Thermodynamic Analysis of Microchannel Heat Sink With Cylindrical Ribs and Cavities

2020 ◽  
Vol 142 (9) ◽  
Author(s):  
Faraz Ahmad ◽  
Taqi Ahmad Cheema ◽  
M. Mohib Ur Rehman ◽  
Muhammad Ilyas ◽  
Cheol Woo Park
Keyword(s):  
Heat Sink ◽  
Side Wall ◽  
Second Law Of Thermodynamics ◽  
Hydrodynamic Performance ◽  
Performance Criteria ◽  
Microchannel Heat Sink ◽  
Transport Efficiency ◽  
Smooth Channel ◽  
Thermal Enhancement ◽  
Staggered Arrangement

Abstract Heat transfer improvement in microchannel heat sink (MCHS) has been a challenge, because it increases the power requirements for the fluid flow. In the present study, MCHS with different wall, geometric, and design configurations of cylindrical ribs and cavities are simulated to investigate their effect on thermal and hydrodynamic performance of MCHS using a laminar flow having Reynolds number in the range from 100 to 1000. The wall configurations include; base wall cylindrical ribs (BWCR), side wall cylindrical ribs (SWCR), and all wall cylindrical ribs (AWCR). Moreover, the geometric configurations involve different AWCR cases having rib spacings (Sfr) of 0.4 mm, 0.8 mm, 1.2 mm, and 0.4 mm staggered arrangement. Furthermore, the design configurations include; AWCR, all wall cylindrical cavities (AWCC), and all wall cylindrical ribs and cavities (AWCRC) with constant Sfr = 0.4 mm. The performance of various channels with flow disruptors is analyzed in terms of friction factor (f) and Nusselt number and then compared with smooth channel in terms of thermal enhancement factor (η). Based on the first law of thermodynamics, thermal resistance (Rth) is used to investigate the resistance of any configuration to flow of heat comparing at same pumping power. Moreover, the second law of thermodynamics is applied to quantify the rate of entropy generation (S˙gen) and transport efficiency (ηt) for MCHS. The results show that although the MCHS with all wall ribs has a lower value of η than the base wall and side wall ribs; however, it has the maximum value of  ηt and minimum value of Rth and S˙gen; thus, indicating that η is not the only performance criteria for the selection of MCHS.

Experimental Study of Pressure Drop and Heat Transfer in a Single-Phase Micropin-Fin Heat Sink

2007 ◽  
Vol 129 (4) ◽  
pp. 479-487 ◽  
Author(s):  
Abel Siu-Ho ◽  
Weilin Qu ◽  
Frank Pfefferkorn
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Pressure Drop ◽  
Friction Factor ◽  
Heat Sink ◽  
Single Phase ◽  
Tip Clearance ◽  
Hydrodynamic Performance ◽  
Pin Fin ◽  
Heat Transfer Correlations

The pressure drop and heat transfer characteristics of a single-phase micropin-fin heat sink were investigated experimentally. Fabricated from 110 copper, the heat sink contained an array of 1950 staggered square micropin fins with 200×200μm2 cross section by 670μm height. The ratios of longitudinal pitch and transverse pitch to pin-fin equivalent diameter are equal to 2. De-ionized water was employed as the cooling liquid. A coolant inlet temperature of 25°C, and two heat flux levels, qeff″=50W∕cm2 and qeff″=100W∕cm2, defined relative to the platform area of the heat sink, were tested. The inlet Reynolds number ranged from 93 to 634 for qeff″=50W∕cm2, and from 127 to 634 for qeff″=100W∕cm2. The measured pressure drop and temperature distribution were used to evaluate average friction factor and local averaged heat transfer coefficient/Nusselt number. Predictions of the previous friction factor and heat transfer correlations that were developed for low Reynolds number (Re<1000) single-phase flow in short pin-fin arrays were compared to the present micropin-fin data. Moores and Joshi’s friction factor correlation (2003, “Effect of Tip Clearance on the Thermal and Hydrodynamic Performance of a Shrouded Pin Fin Array,” ASME J. Heat Transfer, 125, pp. 999–1006) was the only one that provided acceptable predictions. Predictions from the other friction factor and heat transfer correlations were significantly different from the experimental data collected in this study. These findings point to the need for further fundamental study of single-phase thermal/fluid transport process in micropin-fin arrays for electronic cooling applications.

Numerical study of entropy generation and forced convection heat transfer of a nanofluid in a channel with different fin cross-sections

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Zahra Sarbazi ◽  
Faramarz Hormozi
Keyword(s):  
Heat Transfer ◽  
Entropy Generation ◽  
Cross Sections ◽  
Heat Sink ◽  
Silicon Oxide ◽  
Numerical Study ◽  
Copper Substrate ◽  
Substrate Material ◽  
Hydrodynamic Performance ◽  
Content Type

Purpose This study aims to numerically investigate the thermal-hydrodynamic performance of silicon oxide/water nanofluid laminar flow in the heat sink miniature channel with different fin cross-sections. The effect of the fin cross-section including semi-circular, rectangular and quadrant in two directions of flat and curved, and channel substrate materials of steel, aluminum, copper and titanium were examined. Finally, the analysis of thermal and frictional entropy generation in different channels is performed. Design/methodology/approach According to the numerical results, the highest heat transfer coefficients belong to the rectangular, quadrant 2, quadrant 1 and semi-circular fins compared to the channel without fin is 38.65%, 29.94%, 27.45% and 17.1%, respectively. Also, the highest performance evaluation criteria belong to the rectangular and quadrant 2 fins, which have 1.35 and 1.29, respectively. Based on the thermal conductivity of the substrate material, the best material is copper. According to the results of entropy analysis, the reduction of thermal irreversibility of the channel with rectangular, quadrant 1, quadrant 2 and semi-circular compared to non-finned channel is equal to 72%, 57%, 63% and 48%, respectively. Findings The rectangular and quadrant 2 fins are the best fins and the copper substrate material is the best material to reduce the entropy generation. Originality/value The silicon oxide/water nanofluid flow in the heat sink miniature channel with various fin shapes and the curvature angle against the fluid flow was simulated to increase the heat transfer performance. The whole test section is simulated in three-dimensional. Different channel materials have been investigated to find the best channel substrate material.

scholarly journals Thermal and hydrodynamic performance of a microchannel heat sink with carbon nanotube nanofluids

2019 ◽  
Vol 138 (2) ◽  
pp. 937-945 ◽  
Author(s):  
Normah Mohd-Ghazali ◽  
Patrice Estellé ◽  
Salma Halelfadl ◽  
Thierry Maré ◽  
Tng Choon Siong ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Heat Sink ◽  
Hydrodynamic Performance ◽  
Microchannel Heat Sink

Effects of Inlet/Outlet Manifold Configuration on the Thermo-Hydrodynamic Performance of Recharging Microchannel Heat Sink

2020 ◽  
Vol 13 (3) ◽  
Author(s):  
Sangram Kumar Samal ◽  
Manoj Kumar Moharana
Keyword(s):  
Heat Flux ◽  
Fluid Flow ◽  
Thermal Performance ◽  
Heat Sink ◽  
Flow Distribution ◽  
Hydrodynamic Performance ◽  
Bottom Surface ◽  
High Heat Flux ◽  
Microchannel Heat Sink ◽  
Power Requirement

Abstract Thermal performance of microchannel heat sink can be augmented by designing inlet/outlet manifolds such that fluid flow distribution is uniform across microchannels. In this work, the effect of inlet/outlet manifold configurations on the thermo-hydrodynamic performance of recharging microchannel heat sink (RMCHS) is investigated numerically. For this purpose branched, rectangular, trapezoidal, and triangular manifold configurations are considered. All the numerical simulations are performed for channel Reynolds number of 50–300 and constant heat flux of 10 W/cm2 applied on the substrate bottom surface of the RMCHS. The results reveal that branched manifold configuration shows uniform fluid flow distribution across all the microchannels of heat sink and also shows uniform temperature distribution on the substrate bottom surface of RMCHS. Branched manifold configuration reduces thermal resistance by 16% and enhances average Nusselt number by 9.5% compared to rectangular manifold configuration. However, branched manifold configuration shows higher pressure drop in spite of enhancements in thermal performance and flow distribution uniformity. Overall performance analysis indicates that RMCHS with branched manifold configuration can be advantageous for high heat flux removal applications if there is no restriction on pumping power requirement.

Heat Transfer and Hydrodynamic Performance Analysis of a Miniature Tangential Heat Sink Using Al2O3–H2O and TiO2–H2O Nanofluids

2015 ◽  
Vol 29 (4) ◽  
pp. 536-560 ◽  
Author(s):  
Seyed Ziaeddin Miry ◽  
Majid Roshani ◽  
Pedram Hanafizadeh ◽  
Mehdi Ashjaee ◽  
Faezeh Amini
Keyword(s):  
Heat Transfer ◽  
Performance Analysis ◽  
Heat Sink ◽  
Hydrodynamic Performance
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