Numerical Analysis on Natural Convection Heat Transfer of a Heat Sink with Cylindrical Pin Fin

2014 ◽  
Vol 695 ◽  
pp. 398-402
Author(s):  
Yap Zi Qin ◽  
Amer Nordin Darus ◽  
Nor Azwadi Che Sidik
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Thermal Resistance ◽  
Thermal Management ◽  
Heat Sink ◽  
Information Age ◽  
Convection Heat Transfer ◽  
Pin Fin ◽  
Technology Advancement ◽  
Optimum Porosity

As technology advancement progressed in this information age or commonly known as digital age, thermal management has equally improved to keep up with demands from the electronic sector. Hence, heat sink study has become more and more prominent. Natural convection holds advantages since it is maintenance free and has zero power consumption. The purpose of this research is to study the heat transfer performance of heat sink with parametric variations of number and height of pin fin at temperature 308K, 323K, 338K, 353K and 368K. In addition, effect of porosity ranges from 0.524 to 0.960 on thermal resistance was investigated as well. Study found that heat transfer coefficient increases as temperature difference between heat sink and ambient increases. Thermal resistance decreases when porosity increases until it reaches the minimum and subsequently increases. The optimum porosity shown in this study is around 88%.

Experimental and Numerical Investigation of Natural Convection Heat Transfer From Horizontal Rectangular Plate Fin Pin Fin Arrays

2020 ◽  
Author(s):  
Sunil V. Dingare ◽  
Narayan K. Sane ◽  
Ratnakar R. Kulkarni
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Natural Convection ◽  
Numerical Model ◽  
Convection Heat Transfer ◽  
Natural Convection Heat Transfer ◽  
Convection Heat ◽  
Pin Fin ◽  
Pin Fins ◽  
Fin Spacing

Abstract Fins are commonly employed for cooling of electronic equipment, compressors, Internal Combustion engines and for heat exchange in various heat exchangers. In short fin (length to height ratio, L/H = 5) arrays used for natural convection cooling, a stagnation zone forms at the central portion and that portion is not effective for carrying away heat. An attempt is made to modify plate fin heat sink geometry (PFHS) by inserting pin fins in the channels formed between plate fins and a plate fin pin fin heat sink (PFPFHS) is constructed to address this issue. An experimental setup is developed to validate numerical model of PFPFHS. The three-dimensional elliptic governing equations were solved using a finite volume based computational fluid dynamics (CFD) code. Fluent 6.3.26, a finite volume flow solver is used for solving the set of governing equations for the present geometry. Cell count based on grid independence and extended domain is used to obtain numerical results. Initially, the numerical model is validated for PFHS cases reported in the literature. After obtaining a good agreement with results from the literature, the numerical model for PFHS is modified for PFPFHS and used to carry out systematic parametric study of PFPFHS to analyze the effects of parameters like fin spacing, fin height, pin fin diameter, number of pin fins and temperature difference between fin array and surroundings on natural convection heat transfer from PFPFHS. It is observed that it is impossible to obtain optimum performance in terms of overall heat transfer by only concentrating on one or two parameters. The interactions among all the design parameters must be considered. This thesis presents Experimental and Numerical study of natural convection heat transfer from horizontal rectangular plate fin and plate fin pin fin arrays. The parameters of study are fin spacing, temperature difference between the fin surface and ambient air, fin height, pin fin diameter, number of pin fins and method of positioning pin fins in the fin channel. Experimental set up is validated with horizontal plate standard correlations. Results are generated in the form of variation in average heat transfer coefficient (ha), base heat transfer coefficient (hb), average Nusselt number (Nua) and base Nusselt number (Nub). Total 512 cases are studied numerically and finally an attempt is made to correlate the Nusselt Number (Nu), Rayleigh Number (Ra), increase in percentage by inserting pin fins (% Area), ratios like spacing to height (S/H) and L/H obtained in the present study.

scholarly journals Experimental Research and Development on the Natural Convection of Suspensions of Nanoparticles—A Comprehensive Review

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1855 ◽  
Author(s):  
S. M. Sohel Murshed ◽  
Mohsen Sharifpur ◽  
Solomon Giwa ◽  
Josua P. Meyer
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Thermal Management ◽  
Experimental Research ◽  
Thermophysical Properties ◽  
Convection Heat Transfer ◽  
Natural Convection Heat Transfer ◽  
Stability Evaluation ◽  
Convection Heat ◽  
Systems Research

Suspensions of nanoparticles, widely known as nanofluids, are considered as advanced heat transfer media for thermal management and conversion systems. Research on their convective thermal transport is of paramount importance for their applications in such systems such as heat exchangers and solar collectors. This paper presents experimental research on the natural convection heat transfer performances of nanofluids in different geometries from thermal management and conversion perspectives. Experimental results and available experiment-derived correlations for the natural thermal convection of nanofluids are critically analyzed. Other features such as nanofluid preparation, stability evaluation and thermophysical properties of nanofluids that are important for this thermal transfer feature are also briefly reviewed and discussed. Additionally, techniques (active and passive) employed for enhancing the thermo-convection of nanofluids in different geometries are highlighted and discussed. Hybrid nanofluids are featured in this work as the newest class of nanofluids, with particular focuses on the thermophysical properties and natural convection heat transfer performance in enclosures. It is demonstrated that there has been a lack of accurate stability evaluation given the inconsistencies of available results on these properties and features of nanofluids. Although nanofluids exhibit enhanced thermophysical properties such as viscosity and thermal conductivity, convective heat transfer coefficients were observed to deteriorate in some cases when nanofluids were used, especially for nanoparticle concentrations of more than 0.1 vol.%. However, there are inconsistencies in the literature results, and the underlying mechanisms are also not yet well-understood despite their great importance for practical applications.

scholarly journals Effect of an axial hole on natural convection heat transfer from a cylindrical pin fin attached to a horizontal plate

2018 ◽  
Vol 22 (6 Part A) ◽  
pp. 2493-2502
Author(s):  
Saurav Manna ◽  
Subhas Haldar ◽  
Subrata Ghosh
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Convection Heat Transfer ◽  
Base Plate ◽  
Hole Diameter ◽  
Natural Convection Heat Transfer ◽  
Convection Heat ◽  
Horizontal Plate ◽  
Pin Fin ◽  
Laminar Natural Convection

Heat transfer under laminar natural convection from a hollow cylindrical fin mounted on a horizontal base plate has been numerically studied. The flow outside the fin is much stronger than that inside the hole and as a consequence the rate of heat transfer from a hollow fin is primarily due to the contribution by the outer surface of the fin. Fortunately, the rate of heat transfer is not negatively affected by the presence of the hole at the fin centre. On the contrary, when the Grashof number is higher or the hole diameter is bigger, the inside surface contributes marginally to the heat transfer. A hollow fin saves material and weighs less compared to a solid fin. So, this feature may be exploited.

A Study on Improving in Natural Convection Heat Transfer for Heat Sink of High Power LEDs

2011 ◽  
Vol 383-390 ◽  
pp. 6834-6839 ◽  
Author(s):  
Xiang Rui Meng ◽  
Xin Ling Ma ◽  
Ji Fu Lu ◽  
Xin Li Wei
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Heat Sink ◽  
Heat Transfer Performance ◽  
Convection Heat Transfer ◽  
Natural Convection Heat Transfer ◽  
Transfer Performance ◽  
Stagnation Zone ◽  
Convection Heat ◽  
Symmetry Center

In this paper the natural convection heat transfer performance of horizontal heat sink was studied by numerical simulation and experiment. The numerical simulation results show that there are some interesting features in the flow field of heat sink model. 1) Among the fins, the air vertically flows only through the fins in the symmetry center of heat sink while it horizontally flows through the fins in other area. 2) There is an air stagnation zone located at the fin root in the symmetry center of heat sink. These features both caused the decrease in heat transfer temperature difference and heat transfer area in fact. The natural convection heat transfer performance of heat sink is affected at last. In order to eliminate the air stagnation zone and change in the flow way of air, some holes were perforated at the fin root. These holes play its role. In this test, the heat transfer power of heat sink with seven holes has increased by 16.7% compared with the prototype.With the increase in the number of holes, the natural convection heat transfer power of heat sink also increases. But when the number of holes reaches to a value, the increase in the number of holes will not function properly.

scholarly journals Natural-convection heat transfer enhancement of aluminum heat sink using nanocoating by electron beam method

2019 ◽  
Vol 23 (5 Part B) ◽  
pp. 3129-3141
Author(s):  
Senthil Pongiannan ◽  
Velraj Ramalingam ◽  
Latha Nagendran
Keyword(s):  
Heat Transfer ◽  
Surface Roughness ◽  
Electron Beam ◽  
Natural Convection ◽  
Heat Sink ◽  
Heat Dissipation ◽  
Convection Heat Transfer ◽  
Safety Level ◽  
X Ray ◽  
Beam Method

The high power density and compactness of the next generation electronic devices necessitate efficient and effective cooling methods for heat dissipation in order to maintain the temperature at an acceptable safety level. In the present work, aluminum nanocoating was employed in a heat sink to study the heat transfer performance under natural-convection conditions. The nanocoating was achieved using an electron beam method while the characteristics of nanocoated surfaces were analysed using SEM, an energy dispersive X-ray spectroscopy, surface roughness profilometry equipment and by X-ray diffraction techniques. The heat dissipation from heat sink with and without nanocoating under natural-convection has been experimentally studied at different controllable surrounding temperatures. A uniform increase in the surface roughness by the nanocoating was seen in all cases. The conclusion from several experimental results was that the effect of nanocoating in augmenting the heat transfer is more pronounced only when there is a sufficient temperature driving potential.

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