Effect of Heat Sink Structure Improvement on Heat Dissipation Performance in High Heat Flux

2016 ◽  
Author(s):  
Zhuo Cui
Keyword(s):  
Heat Resistance ◽  
Water Flow ◽  
Heat Sink ◽  
Heat Dissipation ◽  
Convection Heat Transfer ◽  
Cooling Water ◽  
High Heat Flux ◽  
Pin Fin ◽  
Pin Fins ◽  
Pin Fin Arrays

This paper presents the effects of heat dissipation performance of pin fins with different heat sink structures. The heat dissipation performance of two types of pin fin arrays heat sink are compared through measuring their heat resistance and the average Nusselt number in different cooling water flow. The temperature of cpu chip is monitored to determine the temperature is in the normal range of working temperature. The cooling water flow is in the range of 0.02L/s to 0.15L/s. It’s found that the increase of pin fins in the corner region effectively reduce the temperature of heat sink and cpu chip. The new type of pin fin arrays increase convection heat transfer coefficient and reduce heat resistance of heat sink.

Experimental and Numerical Analysis of Convective Heat Transfer From Notched Fin Arrays With Pin Fins

2013 ◽  
Author(s):  
Sunil V. Dingare ◽  
Suneeta S. Sane ◽  
Aniket H. Kawade ◽  
Hrishikesh N. Kulkarni ◽  
Kaustibh U. Suranglikar
Keyword(s):  
Heat Transfer ◽  
Numerical Analysis ◽  
Temperature Difference ◽  
Heat Sink ◽  
Convection Heat Transfer ◽  
Heat Sinks ◽  
Central Portion ◽  
Pin Fin ◽  
Pin Fins ◽  
Free Convection Heat

In electronic components, it is essential to provide for adequate cooling to ensure that overheating does not affect the performance. It has been observed that for short fins, (L/H ≤ 5) due to formation of stagnant zone, central portion of fin is ineffective. To overcome this problem central portion from plate fin is removed. By doing so average heat transfer coefficient of notched array was improved almost by 30percentage compared to normal plate fin array. In this study we present computational assessment of notched plate fin heat sink (NPFHS) & notched plate fin pin fin heat sink (NPFPFHS). Based on NPFHS, a NPFPFHS is constructed which is composed of a NPFHS and some columnar pins planted between notched plate fins. Limited experimentation is carried out for validation of numerical model. Numerical analysis is carried out to compare thermal performance of these two types of heat sinks under the condition of equal temperature difference between mean sink temperature and ambient temperature. The effects of fin spacing, fin height, pin fin diameter and temperature difference between fin and surroundings on the free convection heat transfer from horizontal fin arrays were studied. The analysis have been carried out for the two types of heat sinks with three different spacing, three different height, four temperature differences and three pin diameters.

An Active Heat Sink System With Piezoelectric Translational Agitators and Micro Pin Fin Arrays

2012 ◽  
Author(s):  
Taiho Yeom ◽  
Terrence W. Simon ◽  
Youmin Yu ◽  
Min Zhang ◽  
Smita Agrawal ◽  
...  
Keyword(s):  
Heat Sink ◽  
Heat Dissipation ◽  
Single Channel ◽  
Fiber Composite ◽  
Small Displacement ◽  
Carbon Fiber Composite ◽  
Peak Displacement ◽  
Multiple Channel ◽  
Pin Fin ◽  
Pin Fin Arrays

Conventional heat sink systems with blowers or fans are approaching maximum thermal management capability due to dramatically increased heat dissipation from the chips of high power electronics. In order to increase thermal performance of air-cooled heat sink systems, more active or passive cooling components are continually being considered. One technique is to agitate of the flow in the heat sinks to replace or aid conventional blowers. In the present study, an active heat sink system that is coupled with a piezoelectric translational agitator and micro pin fin arrays on the heat sink surfaces is considered. The piezoelectric translational agitator generates high frequency and large displacement motion to a blade. It is driven by an oval loop shell that amplifies the small displacement of the piezo stack actuator to the several-millimeter range. The blade, made of carbon fiber composite, is easily extended to a multiple-blade system without adding much mass. The micro pin fin arrays were created with the LIGA photolithography technique. The cooling performance of the heat sink system was demonstrated in single-channel and multiple-channel test facilities. The singlechannel test results show that the active heat sink with the agitator operating at a frequency of 686 Hz and peak-to-peak displacement of 1.4 mm achieved a low thermal resistance of 0.053 C/W in a channel with a 7.9 m/sec flow velocity. Different configurations of the translational agitator with multiple blades were fabricated and tested in a 26-channel, full-size heat sink. Vibrational characteristics are also provided.

An Elaborate Review for Micro-Fin Heat Sink

2020 ◽  
Vol 38 (1A) ◽  
pp. 105-112
Author(s):  
Ibtisam A. Hasan ◽  
Sahar R. Fafraj ◽  
Israa A. Mohmmad
Keyword(s):  
Heat Transfer ◽  
Thermal Resistance ◽  
Heat Sink ◽  
Heat Dissipation ◽  
Low Cost ◽  
High Heat ◽  
Heat Sinks ◽  
Nano Particles ◽  
High Heat Flux ◽  
Pin Fins

Heat sinks are low cost, the process of manufacturing reliability, and design simplicity which leads to taking into consideration various cutting-edge applications for heat transfer. Like stationary, fuel cells, automotive electronic devices also PV panels cooling and other various applications to improve the heat sinks thermal performance. The aim is to focus on some countless fundamental issues in domains such as; mechanics of fluids and heat transfer, sophisticated prediction for temperature distribution, high heat flux removal, and thermal resistance reduction. The outcome of this survey concluded that the best configuration of heat sinks has a thermal resistance about (0.140 K/W to 0.250 K/W) along with a drop of pressure less than (90.0 KPa) with a temperature gradient about 2 °C/mm. Heat sinks with square pin fins lead to enhance the effectiveness of heat dissipation than heat sinks with microcolumn pin fins. While other researches recommend the use of high conductive coating contains nano-particles. The present survey focuses on the researches about future heat sink with micro fin and the development to resolve the fundamental issues. The main benefits and boundaries of micro fins heat sink briefed.

Comparative Analysis of Heat Transfer and Fluid Flow in Circular and Rhombus Pin Fin Heat Sink Using Nanofluid

2021 ◽  
Vol 13 (5) ◽  
Author(s):  
Dungali Sreehari ◽  
Yogesh K. Prajapati
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Comparative Analysis ◽  
Pressure Drop ◽  
Heat Sink ◽  
Heat Dissipation ◽  
Flow Behavior ◽  
Computational Domain ◽  
Pin Fin ◽  
Pin Fins

Abstract Numerical investigation has been carried out to compare the heat transfer performance and fluid flow behavior of microchannel heat sinks with circular and rhombus pin fins which are arranged in an in-line manner. Diameter and sides are 1 mm for circular and rhombus fins. Three-dimensional (3D) computational domain has been simulated using two types of cooling medium, i.e., water and Al2O3–H2O nanofluid. A comprehensive comparative analysis has been presented considering the coolants and pin fin profiles as variable parameters. Two operating variables, i.e., heat flux (q) and Reynolds number (Re), are varied in the range of q = 100–400 kW/m2 and Re = 100–400. A total of 64 cases have been simulated to identify the promising features of both the pin fins attributed to improved heat transfer and overall thermal performance. Comparison has also been made between the coolant medium to find out their heat dissipation potential and flow characteristics in the heat sink. Results obtained in terms of average bottom wall temperature, heat transfer coefficient, Nusselt number (Nu), and pressure drop demonstrate that heat sink with rhombus pin fins dissipates more heat compared to its counterpart. It is attributed to the shape and geometry of rhombus fins that facilitate distinct fluid flow behavior; nevertheless, the pressure drop is less in the circular fin heat sink. Moreover, for constant value of Re, nanofluid extracts more heat compared to water in both configurations of the heat sink.

Hydoroil-Based Micro Pin Fin Heat Sink

2006 ◽  
Author(s):  
Ali Kosar ◽  
Chih-Jung Kuo ◽  
Yoav Peles
Keyword(s):  
Heat Sink ◽  
Hydraulic Performance ◽  
Heat Fluxes ◽  
Heat Sinks ◽  
Transfer Coefficients ◽  
Pin Fin ◽  
Nusselt Numbers ◽  
Friction Factors ◽  
Pin Fins ◽  
Micro Pin Fins

An experimental study on thermal-hydraulic performance of de-ionized water over a bank of shrouded NACA 66-021 hydrofoil micro pin fins with wetted perimeter of 1030-μm and chord thickness of 100 μm has been performed. Average heat transfer coefficients have been obtained over effective heat fluxes ranging from 4.0 to 308 W/cm2 and mass velocities from 134 to 6600 kg/m2s. The experimental data is reduced to the Nusselt numbers, Reynolds numbers, total thermal resistances, and friction factors in order to determine the thermal-hydraulic performance of the heat sink. It has been found that prodigious hydrodynamic improvement can be obtained with the hydrofoil-based micro pin fin heat sink compared to the circular pin fin device. Fluid flow over pin fin heat sinks comprised from hydrofoils yielded radically lower thermal resistances than circular pin fins for a similar pressure drop.

scholarly journals Active heat sink with piezoelectric translational agitators, piezoelectric synthetic jets, and micro pin fin arrays

2018 ◽  
Vol 99 ◽  
pp. 190-199 ◽  
Author(s):  
Taiho Yeom ◽  
Terrence Simon ◽  
Min Zhang ◽  
Youmin Yu ◽  
Tianhong Cui
Keyword(s):  
Heat Sink ◽  
Synthetic Jets ◽  
Pin Fin ◽  
Pin Fin Arrays

Row Removal Heat Transfer Study for Pin Fin Arrays

2014 ◽  
Author(s):  
Kathryn L. Kirsch ◽  
Jason K. Ostanek ◽  
Karen A. Thole ◽  
Eleanor Kaufman
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
High Reynolds Number ◽  
Pin Fin ◽  
Heat Transfer Augmentation ◽  
Aspect Ratios ◽  
Pin Fins ◽  
High Reynolds ◽  
Pin Fin Arrays ◽  
Transfer Study

Arrays of variably-spaced pin fins are used as a conventional means to conduct and convect heat from internal turbine surfaces. The most common pin shape for this purpose is a circular cylinder. Literature has shown that beyond the first few rows of pin fins, the heat transfer augmentation in the array levels off and slightly decreases. This paper provides experimental results from two studies seeking to understand the effects of gaps in pin spacing (row removals) and alternative pin geometries placed in these gaps. The alternative pin geometries included large cylindrical pins and oblong pins with different aspect ratios. Results from the row removal study at high Reynolds number showed that when rows four through eight were removed, the flow returned to a fully-developed channel flow in the gap between pin rows. When larger alternative geometries replaced the fourth row, heat transfer increased further downstream into the array.

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.

Comparison of Pin Surface Heat Transfer in Arrays of Oblong and Cylindrical Pin Fins

2013 ◽  
Vol 136 (4) ◽  
Author(s):  
Kathryn L. Kirsch ◽  
Jason K. Ostanek ◽  
Karen A. Thole
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Boundary Layer Separation ◽  
Diameter Ratio ◽  
Pin Fin ◽  
The Third ◽  
Spacing Effects ◽  
Pin Fins ◽  
Turbine Airfoils ◽  
Pin Fin Arrays

Pin fin arrays are most commonly used to promote convective cooling within the internal passages of gas turbine airfoils. Contributing to the heat transfer are the surfaces of the channel walls as well as the pin itself. Generally the pin fin cross section is circular; however, certain applications benefit from using other shapes such as oblong pin fins. The current study focuses on characterizing the heat transfer distribution on the surface of oblong pin fins with a particular focus on pin spacing effects. Comparisons were made with circular cylindrical pin fins, where both oblong and circular cylindrical pins had a height-to-diameter ratio of unity, with both streamwise and spanwise spacing varying between two and three diameters. To determine the effect of relative pin placement, measurements were taken in the first of a single row and in the third row of a multirow array. Results showed that area-averaged heat transfer on the pin surface was between 30 and 35% lower for oblong pins in comparison to cylindrical. While heat transfer on the circular cylindrical pin experienced one minimum prior to boundary layer separation, heat transfer on the oblong pin fins experienced two minimums, where one is located before the boundary layer transitions to a turbulent boundary layer and the other prior to separation at the trailing edge.

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