Pin-Fin Heat Sink With Horizontal Base and Blocked Edges

2008 ◽  
Author(s):  
D. Sahray ◽  
H. Shmueli ◽  
N. Segal ◽  
G. Ziskind ◽  
R. Letan
Keyword(s):  
Heat Transfer ◽  
Free Convection ◽  
Contact Resistance ◽  
Cross Section ◽  
Heat Input ◽  
Heat Sink ◽  
Numerical Study ◽  
Heat Sinks ◽  
Transfer Enhancement ◽  
Pin Fin

In the present work, horizontal-base pin fin heat sinks exposed to free convection in air are studied. They are made of aluminum, and there is no contact resistance between the base and the fins. For the same base dimensions the fin height and pitch vary. The fins have a constant square cross-section. The edges of the sink are blocked: the surrounding insulation is flush with the fin tips. The effect of fin height and pitch on the performance of the sink is studied experimentally and numerically. In the experiments, the heat sinks are heated using foil electrical heaters. The heat input is set, and temperatures of the base and fins are measured. In the corresponding numerical study, the sinks and their environment are modeled using the Fluent 6 software. The results show that heat transfer enhancement due to the fins is not monotonic. The differences between sparsely and densely populated sinks are analyzed for various fin heights. Also assessed are effects of the blocked edges as compared to the previously studied cases where the sink edges were exposed to the surroundings.

Effect of Fin Pitch and Height on Pin-Fin Heat Sink Performance

2008 ◽  
Author(s):  
D. Sahray ◽  
H. Shmueli ◽  
N. Segal ◽  
G. Ziskind ◽  
R. Letan
Keyword(s):  
Heat Transfer ◽  
Free Convection ◽  
Contact Resistance ◽  
Cross Section ◽  
Heat Input ◽  
Heat Sink ◽  
Numerical Study ◽  
Heat Sinks ◽  
Transfer Enhancement ◽  
Pin Fin

In the present work, horizontal-base pin fin heat sinks exposed to free convection in air are studied. They are made of aluminum, and there is no contact resistance between the base and the fins. The sinks have the same base dimensions whereas the fin height and pitch vary. The fins have a constant square cross-section. The effect of fin height and pitch on the performance of the sink is studied experimentally and numerically. In the experiments, the heat sinks are heated using foil electrical heaters. The heat input is set, and temperatures of the base and fins are measured. In the corresponding numerical study, the sinks and their environment are modeled using the Fluent 6.3 software. The results show that heat transfer enhancement due to the fins is not monotonic. The differences between sparsely and densely populated sinks are analyzed for various fin heights.

Cooling Performance Comparisons of Five Different Plate-Pin Compound Heat Sinks Based on Two Different Length Scale

2011 ◽  
Author(s):  
Feng Zhou ◽  
David Geb ◽  
Ivan Catton
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Heat Transfer Enhancement ◽  
Cross Section ◽  
Heat Sink ◽  
Heat Sinks ◽  
Length Scale ◽  
Transfer Enhancement ◽  
Pin Fin ◽  
New Type

Plate fin heat sinks (PFHS) are widely used to remove heat from the microelectronic devices. In the present study, a new type of compound heat sink, named as plate-pin fin heat sink (PPFHS), is employed to improve the air cooling performance. With CFD numerical method, PPFHSs with five forms of pin cross-section profiles (square, circular, elliptic, NACA 0050, and dropform) and PFHS were simulated. Two different length scales were adopted to evaluate the performance of six types of heat sinks, including PFHS. One of the length scales is commonly used by many investigators, which is two times of the channel spacing. The other length scale is suggested by volume averaging theory (VAT), which is four times of average porosity divided by specific interface. The influence of pin fin cross-section profile on the flow and heat transfer characteristics was presented by means of Nusselt number, pressure drop and overall efficiency. It is found that the Nu number of a PPFHS is at least 35% higher than that of a PFHS used to construct the PPFHS at the same Reynolds number no matter which length scale was used. It is also revealed that the heat transfer enhancement of square PPFHS is offset by its excessively high pressure drop, which makes it not as efficient as the other types of PPFHS. Circular PPFHS performs similar to the streamline shaped PPFHS when the Reynolds number is not too high. However, with the increase in Re the advantage of the circular cross-section diminishes. Using the streamline shaped pins, not only the pressure drop of the compound heat sinks could be decreased considerably, the heat transfer enhancement also makes a step forward. However, evaluating the performance of heat sinks by using the commonly used length scale, the benefit of streamline shaped types of PPFHSs is a little bit overstated. The VAT suggested length scale is more reasonable to do the performance comparison of different heat sinks, especially when it is difficult to provide a fair and physically meaningful basis for the comparison. In short, the present numerical simulation provides original information of the influence of different pin-fin cross-section profiles on the thermal and hydraulic performance of the new type compound heat sink and emphasizes the importance of choosing a proper length scale when evaluating heat transfer enhancement, which is helpful in the design of heat sinks.

Numerical Analysis of Entropy Generation in Array of Pin-Fin Heat Sinks for Some Different Geometries

2010 ◽  
Author(s):  
Reza Kamali ◽  
Bamdad Barari ◽  
Ashkan Abbasian Shirazi
Keyword(s):  
Heat Transfer ◽  
Numerical Analysis ◽  
Pressure Drop ◽  
Cross Section ◽  
Entropy Generation ◽  
Heat Sink ◽  
Control Volume ◽  
Heat Sinks ◽  
Entropy Generation Rate ◽  
Pin Fin

In this study, Numerical analysis has been used to investigate entropy generation for array of pin-fin heat sink. Technique is applied to study the thermodynamic losses caused by heat transfer and pressure drop in pin-fin heat sinks. A general expression for the entropy generation rate is obtained by considering the whole heat sink as a control volume and applying the conservation equations for mass and energy with the entropy balance. Analytical and empirical correlations for heat transfer coefficients and friction factors are used in the numerical modeling. Also effects of heat transfer and pressure drop in entropy generation in control volume over pin-fins have been studied. Numerical analysis has been used for three different models of pin-fin heat sinks. The models are different in cross section area. These cross section areas are circle, horizontal ellipse and vertical ellipse which mentioned in next sections. Reference velocity used in Reynolds number and pressure drop is based on the minimum free area available for the fluid flow. Also for numerical analysis in-line arrangement of fins has been investigated and their relative performance is compared. At the end, the performance of these three models has been compared.

Scale-Up and Generalization of Horizontal-Base Pin-Fin Heat Sinks in Natural Convection and Radiation

2010 ◽  
Vol 132 (11) ◽  
Author(s):  
D. Sahray ◽  
G. Ziskind ◽  
R. Letan
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Characteristic Length ◽  
Numerical Study ◽  
Scale Up ◽  
Heat Sinks ◽  
Transfer Enhancement ◽  
Numerical Investigations ◽  
Pin Fin ◽  
Base Size

This paper provides further insight in heat transfer from horizontal-base pin fin heat-sinks in free convection of air. The main objective is to assess the effect of base size, and this with regard to the effects of fin height and fin population density studied in a previous work (Sahray, D., et al., 2010, “Study and Optimization of Horizontal-Base Pin-Fin Heat Sinks in Natural Convection and Radiation,” ASME J. Heat Transfer, 132(012503), pp. 1–13). To this end, experimental and numerical investigations are performed with sinks of different base sizes. The sinks are made of aluminum, with no contact resistance between the base and the fins, and are heated using foil electrical heaters. In the corresponding numerical study, the sinks and their environment are modeled using the FLUENT 6.3 software. In the experiments, sink bases of 100×100 mm2 and 200×200 mm2 are used, while in the numerical study sinks of 50×50 mm2 are investigated, too. In addition to the sinks with exposed, free edges (Sahray, D., et al., 2010, “Study and Optimization of Horizontal-Base Pin-Fin Heat Sinks in Natural Convection and Radiation,” ASME J. Heat Transfer, 132(012503), pp. 1–13), the same sinks are explored also with their edges blocked. This is done in order to exclude the edge effect, thus making it possible to estimate heat transfer from a sink of an “infinite” base size. Heat-transfer enhancement due to the fins is assessed quantitatively and analyzed for various base sizes and fin heights. The effect of fin location in the array on its contribution to the heat-transfer rate from the sink is analyzed. By decoupling convection from radiation, a dimensional analysis of the results for natural convection is attempted. Interdependence of the base size and fin height effects on the heat transfer is demonstrated. A correlation that encompasses all the cases studied herein is obtained, in which the Nusselt number depends on the Rayleigh number, which uses the “clear” spacing between fins as the characteristic length, and on the dimensions of the fins and the base.

Study of Horizontal-Base Pin-Fin Heat Sinks in Natural Convection

2007 ◽  
Author(s):  
D. Sahray ◽  
R. Magril ◽  
V. Dubovsky ◽  
G. Ziskind ◽  
R. Letan
Keyword(s):  
Heat Transfer ◽  
Transfer Rate ◽  
Characteristic Length ◽  
Numerical Study ◽  
Heat Sinks ◽  
Transfer Enhancement ◽  
Total Heat Transfer ◽  
Pin Fin ◽  
Relative Contribution ◽  
Fin Spacing

The present paper deals with horizontal-base pin fin heat sinks in free convection. The sinks have the same base dimensions and variable fin pitch. They are made of aluminum, and there is no contact resistance between the base and the fins. The fins have a constant square cross-section. The effect of fin pitch on the performance of the sink is studied experimentally and numerically. In the experiments, the heat sinks are heated using foil electrical heaters. The heat input is set, and temperatures of the base and fins are measured. In the corresponding numerical study, the sinks are modeled using the Fluent 6 software. The results show that heat transfer enhancement due to the fins is not monotonic. The differences between sparsely and densely populated sinks are analyzed. Also analyzed are the effects of the sink edges on the total heat transfer. A relative contribution of outer and inner fin rows in the sink is assessed, together with the effect of fin location in the array on the heat transfer rate from an individual fin. Dimensional analysis of the results is attempted, and a correlation presenting the Nusselt number vs. the Rayleigh number is suggested, where the inter-fin spacing serves as the characteristic length.

Study and Optimization of Horizontal-Base Pin-Fin Heat Sinks in Natural Convection and Radiation

2009 ◽  
Vol 132 (1) ◽  
Author(s):  
D. Sahray ◽  
H. Shmueli ◽  
G. Ziskind ◽  
R. Letan
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Flux Distribution ◽  
Characteristic Length ◽  
Numerical Study ◽  
Heat Sinks ◽  
Heat Flux Distribution ◽  
Transfer Enhancement ◽  
Pin Fin ◽  
Relative Contribution

This paper aims at deeper understanding of heat transfer from horizontal-base pin-fin heat sinks with exposed edges in free convection of air. The effects of fin height and fin population density are studied experimentally and numerically. The sinks are made of aluminum, and there is no contact resistance between the base and the fins. All the sinks studied have the same base dimensions and are heated using foil electrical heaters. The fins have a constant square cross section, whereas the fin height and pitch vary. The heat input is set, and temperatures of the base and fins are measured. In the corresponding numerical study, the sinks and their environment are modeled using the FLUENT 6.3 software. The results show that heat-transfer enhancement due to the fins is not monotonic. The differences between sparsely and densely populated sinks are assessed quantitatively and analyzed for various fin heights. Also analyzed is the heat flux distribution at the edges and center of the sink. A relative contribution of outer and inner fin rows in the sink is assessed, together with the effect of fin location in the array on the heat-transfer rate from an individual fin. By decoupling convection from radiation, a dimensional analysis of the results for natural convection is attempted. A correlation presenting the Nusselt number versus the Rayleigh number is suggested, where the “clear” spacing between fins serves as the characteristic length.

Numerical Predictions of Thermal and Hydraulic Performances of Heat Sinks With Enhanced Heat Transfer Capability

2011 ◽  
Author(s):  
Feng Zhou ◽  
Nicholas Hansen ◽  
Ivan Catton
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Cross Section ◽  
Heat Sink ◽  
Heat Sinks ◽  
Pin Fin ◽  
Numerical Predictions ◽  
Pin Fins ◽  
New Type ◽  
Cross Section Profile

The plate-pin fin heat sink (PPFHS) is composed of a plate fin heat sink (PFHS) and some pin fins planted between the flow channels. In this paper, a numerical investigation was performed to compare the thermal and hydraulic performances of the PPFHSs and PFHS. PPFHSs with five forms of pin cross-section profiles (square, circular, elliptic, NACA 0050, and dropform) were numerically simulated. The influence of pin fin cross-section profile on the flow and heat transfer characteristics was presented by means of Nusselt number and pressure drop. It is found that the Nu number of a PPFHS is at least 35% higher than that of a PFHS used to construct the PPFHS at the same Reynolds number. Planting circular and square pins into the flow channel of heat sinks enhances the heat transfer at the expense of high pressure loss. Using the streamline shaped pins, not only the pressure drop of the compound heat sinks could be decreased considerably, the heat transfer enhancement also makes a step forward. The present numerical simulation provides original information of the influence of different pin-fin cross-section profiles on the thermal and hydraulic performance of the new type compound heat sink, which is helpful in the design of heat sinks.

THERMAL PERFORMANCE OF VERTICAL HEAT SINKS WITH DIFFERENT PIEZOFAN ARRANGEMENTS

2013 ◽  
Vol 37 (3) ◽  
pp. 895-903 ◽  
Author(s):  
Jin-Cherng Shyu ◽  
Jhih-Zong Syu
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Enhancement ◽  
Thermal Performance ◽  
Heat Sink ◽  
Heat Sinks ◽  
Transfer Enhancement ◽  
Pin Fin ◽  
Enhancement Factors ◽  
Vertical Heat

This study examines various effects on the heat transfer enhancement of several vertical heat sinks with a running piezofan. Both plate-fin heat sink and pin-fin heat sink having a 10-mm-high or 30-mm-high fin array were tested with either a vertical or a horizontal piezofan. Results show that the piezofan tip located at x/L = 0.5 usually yielded the highest heat transfer enhancement. Besides, heat transfer enhancement factors ranged from 1.2 to 2.4 for the present 10-mm-high plate-fin heat sink, and from 1.1 to 2.6 for the 10-mm-high pin-fin heat sink.

scholarly journals Thermal Analysis of Vertical Plate Fin Heat Sink

2020 ◽  
Vol 170 ◽  
pp. 01022
Author(s):  
Anilkumar Sathe ◽  
Sudarshan Sanap ◽  
Sunil Dingare ◽  
Narayan Sane
Keyword(s):  
Heat Transfer ◽  
Thermal Analysis ◽  
Pressure Drop ◽  
Free Convection ◽  
Experimental Method ◽  
Heat Input ◽  
Heat Sink ◽  
Vertical Plate ◽  
Heat Sinks ◽  
Power Requirement

Heat Sinks are widely used to remove the heat from the components which are generating heat during their functioning. Overheating causes malfunctioning of the components as well as it is responsible for reducing their life. Free convection is very common way of heat transfer from the heat sink considering power requirement, pressure drop and cost of the forced convection. This paper presents the thermal analysis of vertical plate fin heat sink by theoretical and experimental method at variable heat input. The results are obtained by taking experimental observations and are validated with already existing correlations suggested by various researchers in the literature.

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