scholarly journals CFD Optimization of free Convective Cooling of Finned Heat Sinks: Effect of Fin Spacing

2015 ◽  
Vol 127 ◽  
pp. 155-161 ◽  
Author(s):  
Soubhik Kumar Bhaumik ◽  
Rashmita Behera
Keyword(s):  
Heat Sinks ◽  
Convective Cooling ◽  
Fin Spacing ◽  
Cfd Optimization

Thermally Optimum Natural Convection Cooled Longitudinal-Plate Heat Sinks With Horizontal Base Plates

2001 ◽  
Author(s):  
K. K. Sikka ◽  
C. George
Keyword(s):  
Natural Convection ◽  
Heat Sink ◽  
Base Plate ◽  
Heat Sinks ◽  
Geometrical Parameters ◽  
Plate Heat ◽  
Horizontal Orientation ◽  
Fin Spacing ◽  
Base Plates ◽  
Weakly Dependent

Abstract Longitudinal-plate fin heat sinks are optimized under natural convection conditions for the horizontal orientation of the heat sink base plate. The thermal performance of the heat sinks is numerically modeled. The fin height, thickness and spacing and heat sink width are systematically varied. The numerical results are validated by experimentation. Results show that the thermal resistance of a heat sink minimizes for a certain number of fins on the base plate. The fin spacing-to-length ratio at which the minimum occurs is weakly dependent on the fin height and thickness and heat sink width. The flow fields reveal that the minimum occurs for the heat sink geometry in which the number of fins are maximized such that the flow velocity as the air exits the fins is fully developed. A correlation of the heat transfer with the heat sink geometrical parameters is also developed.

scholarly journals Numerical study for heat transfer enhancement using CuO water nanofluids through mini-channel heat sinks for microprocessor cooling

2020 ◽  
Vol 24 (5 Part A) ◽  
pp. 2965-2976 ◽  
Author(s):  
Muhammad Anwar ◽  
Hussain Tariq ◽  
Ahmad Shoukat ◽  
Hafiz Ali ◽  
Hassan Ali
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Enhancement ◽  
Numerical Study ◽  
Heat Removal ◽  
Maximum Flow ◽  
Heat Sinks ◽  
Base Temperature ◽  
Transfer Enhancement ◽  
Percentage Difference ◽  
Fin Spacing

Water cooled heat sinks are becoming popular due to increased heat generation inside the microprocessor. Timely heat removal from microprocessor is the key factor for better performance and long life. Heat transfer enhancement is reached either by increasing the surface area density and/or by altering the base fluid properties. Nanoparticles emerge as a strong candidate to increase the thermal conductivity of base fluids. In this research, the thermal performance of mini-channel heat sinks for different fin spacing (0.2 mm, 0.5 mm, 1 mm, and 1.5 mm) was investigated numerically using CuO-water nanofluids with volumetric concentration of 1.5%. The numerical values computed were than compared with the literature and a close agreement is achieved. We recorded the minimum base temperature of chip to be 36.8?C for 0.2 mm fin spacing heat sink. A reduction of 9.1% in base temperature was noticed using CuO-water nanofluids for 0.2 mm fin spacing as compared to previously experimental estimated value using water [1]. The drop percentage difference in pressure between water and CuO-water nanofluids was 2.2-13.1% for various fin spacing heat sinks. The percentage difference in thermal resistance between water and CuO-water nanofluids was computed 12.1% at maximum flow rate. We also observed uniform temperature distribution for all heat sinks.

Natural Convection From Finned Heat Sinks

2007 ◽  
Author(s):  
L. T. Yeh ◽  
Joseph Yeh ◽  
B. T. F. Chung
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Heat Sink ◽  
Plate Thickness ◽  
Heat Sinks ◽  
Cfd Model ◽  
Practical Applications ◽  
Computational Fluid Dynamics Analysis ◽  
Fin Spacing ◽  
Fin Length

A CFD (computational fluid dynamics) analysis is performed on the finned heat sinks. For convenience, a commercial CFD code, Flotherm, is utilized in the analysis. Though the code can handle the radiation heat transfer, the present analysis is limited to the natural convection with the base of the heat sink at a constant temperature. The continuous fin configuration is first considered due to the importance of its applications. Several experimental data are available for the vertically straight-fin heat sink and a useful correlation is also developed. For given overall fin dimensions of 15″ × 10.341″ × 2.2″, the correlations are first employed to determine the optimal fin spacing. This optimal fin spacing of 0.439 in is then used to develop the baseline CFD model. The dimensions of the baseline CFD model are as follows: Fin width (in): 10.341. Heat sink length (in): 15. Fin spacing (in): 0.439. Fin height (in): 2.0. Fin thickness (in): 0.1. Fin base plate thickness (in): 0.2. Fin numbers: 20. The baseline model with various fin spacing is analyzed and the results (heat loss from the finned heat sink) compare well with those obtained through the correlations. The analysis is extended to the staggered and in-line fin configurations because of their practical applications. Three different fin lengths, including 1″, 3″ and 5″ fin length for the staggered fin array are examined. The results indicate that the effectiveness of heat transfer is increased as the fin length increasing. The continuous fin configuration is the most efficient, and is followed by the staggered fins and then by the in-line fins.

Performance Prediction for Partially-Confined Heat Sinks

2003 ◽  
Author(s):  
Tzer-Ming Jeng ◽  
Meng-Ping Wang ◽  
Ying-Huei Hung
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Flow Velocity ◽  
Heat Sink ◽  
Convection Heat Transfer ◽  
Thermal Conductance ◽  
Optimal Number ◽  
Performance Parameter ◽  
Heat Sinks ◽  
Fin Spacing

In the present study, the forced air convection heat transfer for unconfined and confined heat sinks by considering flow bypass effect is studied on a semi-empirical basis. The flow bypass effect for unconfined heat sinks is firstly investigated. For unconfined heat sinks with specified fin spacing and fin height, the results reveal that the value of Ui/(ε·Us), which represents the flow bypass capability, increases from a very small Reynolds number up to a certain Reynolds number, say Rei = 60–200; and then gradually decrease with further increasing Reynolds number. At a specified Reynolds number, the Ui/(ε·Us) will generally increase when the fin spacing decreases or the fin height increases. For heat sinks partially confined in a channel, a novel concept to estimate an imaginative flow domain, in which the flow is influenced due to the existence of heat sink in the channel, is postulated in the study. Accordingly, an effective method for predicting the flow velocity between fins, flow rate through the heat sink and the fin heat transfer coefficient in both unconfined flow and confined flow is presented. Finally, in order to explore the optimal number of fins, a performance parameter defined as the ratio of thermal conductance to the required pumping power is introduced; an optimal procedure to determine the maximum performance parameter for a heat sink partially confined in a channel is postulated. The results manifest that the optimal number of fins increases with increasing inlet flow velocity.

Water cooled minichannel heat sinks for microprocessor cooling: Effect of fin spacing

2014 ◽  
Vol 64 (1-2) ◽  
pp. 76-82 ◽  
Author(s):  
Saad Ayub Jajja ◽  
Wajahat Ali ◽  
Hafiz Muhammad Ali ◽  
Aysha Maryam Ali
Keyword(s):  
Heat Sinks ◽  
Cooling Effect ◽  
Fin Spacing

Thermal Performance of Two and Three Dimensional Radial Flow Heat Sinks

2009 ◽  
Author(s):  
Ronan Grimes ◽  
Kieran Hanly ◽  
Edmond Walsh
Keyword(s):  
Heat Transfer ◽  
Heat Sink ◽  
Angular Displacement ◽  
Three Dimensional ◽  
Heat Sinks ◽  
Electronic Systems ◽  
Two Dimensional ◽  
Pressure Drops ◽  
Low Profile ◽  
Fin Spacing

Space and power constraints in many contemporary electronic systems place a greater importance than ever on efficient thermal management solutions. This paper investigates the performance and optimisation of air cooled heat sinks suitable for deployment in compact electronic devices. The heat sinks examined have circular footprint, with air flowing from the centre, radially outwards through radially aligned channels. Heat sink height is examined through experiments which were performed on heat sinks with high and low fins, with two and three dimensional flow and heat transfer phenomena respectively. In both cases the effect of angular fin spacing is investigated to determine optimum fin spacing for a range of heat sink pressure drops. Heat transfer correlations from literature which were originally developed for parallel finned heat sinks are compared with the experimental data. The main findings of the paper are that the performance of the high profile two dimensional heat sink is more sensitive to fin angular displacement than low profile three dimensional heat sinks. The parallel fin correlations from literature were found to predict the performance of the three dimensional heat sinks more accurately than the two dimensional heat sinks.

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.

Optimization of Pool Boiling Heat Sinks Including the Effects of Confinement in the Interfin Spaces

2008 ◽  
Vol 130 (4) ◽  
Author(s):  
Karl J. L. Geisler ◽  
Avram Bar-Cohen
Keyword(s):  
Heat Sinks ◽  
Advanced Materials ◽  
Transfer Coefficients ◽  
Element Analysis ◽  
Heat Transfer Coefficients ◽  
Optimum Heat ◽  
Parameter Ranges ◽  
Fin Thickness ◽  
The Relationship ◽  
Fin Spacing

A finite element analysis approach is developed and used to efficiently evaluate and optimize the boiling performance of longitudinal rectangular plate fin heat sinks, including the explicit dependence of fin spacing on boiling heat transfer coefficients and on the critical heat flux (CHF). Polished silicon heat sinks are shown to dissipate at nearly five times the CHF limit of the unfinned base area and outperform comparable aluminum heat sinks by a factor of 2. For optimum heat sink geometries, over the parameter ranges explored, the fin thickness is found to be approximately equal to the fin spacing, and the relationship between the optimum thickness and spacing is demonstrated to be relatively insensitive to the fin thermal conductivity. Results suggest that even greater performance enhancements may be gained with appropriately-selected advanced materials.

Optimization of Pool Boiling Heat Sinks Including the Effects of Confinement in the Interfin Spaces

2007 ◽  
Author(s):  
Karl J. L. Geisler ◽  
Avram Bar-Cohen
Keyword(s):  
Heat Sinks ◽  
Advanced Materials ◽  
Transfer Coefficients ◽  
Element Analysis ◽  
Heat Transfer Coefficients ◽  
Optimum Heat ◽  
Parameter Ranges ◽  
Fin Thickness ◽  
The Relationship ◽  
Fin Spacing

A finite element analysis (FEA) approach is developed and used to efficiently evaluate and optimize the boiling performance of longitudinal rectangular plate fin heat sinks, including the explicit dependence of fin spacing on boiling heat transfer coefficients and CHF. Polished silicon heat sinks are shown to dissipate nearly five times the CHF limit of the unfinned base area and outperform comparable aluminum heat sinks by a factor of two. For optimum heat sink geometries, over the parameter ranges explored, fin thickness is found to be approximately equal to the fin spacing, and the relationship between optimum thickness and spacing is demonstrated to be relatively insensitive to fin thermal conductivity. Results suggest that even greater performance enhancements may be gained with appropriately-selected advanced materials.

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