• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.12 no.1
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• pp.25-32
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• 2008

A pin fin is optimized based on the increasing rate of heat loss by using a two-dimensional analytic method. The optimum heat loss, corresponding optimum thermal resistance and fin length are presented as a function of the fin base thickness, convection characteristic numbers ratio, fin outer radius and ambient convection characteristic number. One of the results shows that both the optimum heat loss and fin length decrease linearly whereas the optimum thermal resistance increases very slightly with increase of the fin base thickness.

• Journal of the Korean Society of Propulsion Engineers
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• v.24 no.5
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• pp.43-55
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• 2020

The effect of cutted pin in front of pin-fin array was analyzed for increasing the cooling performance of gas turbine blade. The numerical simulations were conducted to figure out the flow and thermal characteristics. The base case which is staggered pin-fin array, cut pin case 1 which has X₂/D_p=1.25 cut pin and cut pin case 2 which has X₃/D_p=1.75 cut pin were compared. The results showed that cut pin increases the strength of the horseshoe vortex which occurred at the leading edge of pin-fin array. Furthermore, the wake effect is reduced at the trailing edge of pin-fin array. As a result, the heat transfer distribution on the endwall increases. However, the friction factor increases owing to the installation of cut pin, but the thermal performance factor is increased maximum 23.8% in cut pin case 2. Therefore, installation of cut pin will be helpful for increasing the cooling performance of pin-fin array of gas turbine blade.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.18 no.6
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• pp.459-467
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• 2006

Rapid development of electronic technology requires small size, high density packaging and high power in the electronic devices, which results in more heat generation. Suitable heat dissipation is required to ensure the guaranteed performance and reliable operation of the current state-of-the-art electronic equipment. The aim of the present study is to find out the forced-convective thermal-hydraulic characteristics of a pin-fin heat exchanger as a candidate for cooling system of the electronic devices through the analysis and experiment. Various configuration of the pin-fin array is selected in order to find out the effect of spacing and diameter of the pin-fin on the heat transfer and pressure drop characteristics. Experimental results are compared with the analyses and correlations of several researchers. Finally, the design guide are provided for the required pressure drop and/or the heat transfer characteristics of the heat exchanger.

• Journal of the Korean Society of Propulsion Engineers
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• v.23 no.3
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• pp.35-43
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• 2019

In this study, a guide vane with varying positions and incidence angles was adopted to a pin-fin channel to analyze the change in thermal performance and pressure loss characteristics. A numerical analysis was conducted to investigate the effect of incidence angles and positions on heat transfer and flow characteristics at Re =1400. The results of it were compared those of a pin-fin channel without a guide vane. In case 1 when the incidence angle is $0^{\circ}$, the heat transfer performance is maximized and improved by approximately 5% when compared to the pin-fin channel without the guide vane. In case 2 when the incidence angle is $10^{\circ}$, the pressure loss is minimized and decreased by approximately 1.9% when compared to the pin-fin channel without the guide vane.

• Journal of the Korean Society of Propulsion Engineers
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• v.23 no.4
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• pp.28-34
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• 2019

In this study, pin-fin arrays, which are widely used for cooling turbine blades, were studied. The vortex generator in pin-fin arrays is located in front of the circular tube. The cross-section of the vortex generator is NACA-9410. The purpose of this study is to analyze heat transfer performance and flow characteristics of pin-fin arrays. The position of vortex generator is changed with the vertical flow direction on the bottom wall. Pin-fin arrays were calculated with 6000, 10000 and 15000 Reynolds number. The commercial program ANSYS v18.0 CFX and the turbulence model $k-{\omega}$ SST were used. As a result, the heat transfer performance increased up to 5.8% and pressure loss increased less than 1%.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.13 no.4
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• pp.271-287
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• 2001

This paper has been made to investigate the thermal performance characteristics for the several types of layered aluminum heat sinks with offset-strip fin. Heat sinks with different fin height, fin length, number of fin layer and slanted fin are prepared and tested for natural convection as well as forced convection. The experimental results for layered heat sink(LHS) are compared to those for advanced pin fin heat sink (PHS) so that the appropriate heat sink can be designed or chosen according to the heating conditions. The overall heat transfer performances for LHS are almost comparable to those of PHS under natural convection, and become 1.2∼1.5 times as high as those of PHS under forced convection situation. This study shows that fin height and number of fin layer re important parameters, which have a serious influence on thermal performance for layered heat sinks.

• Journal of computational fluids engineering
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• v.21 no.3
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• pp.98-109
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• 2016

The flow and heat transfer characteristics of a heat exchanger having rectangular pin-fin in the flow direction have been investigated numerically. On the bottom plate, the convective boundary conditions for the hot side was given, and the fins were arranged in a channel-type geometric model using the periodic boundary condition in the span-wise direction. Three-dimensional numerical calculations for the flow and conjugate heat transfer problem were conducted using SIMPLE algorithm and $k-{\varepsilon}$ turbulence model. For the slanted pin-fin models, it was found that the downward cooling flow is generated due to the downward pressure gradient component, which can enhance the heat transfer performance near the bottom surface and the fin stem region. Four different inclined angles were considered in the Reynolds number range of 13,500-55,000. The aero-thermal performance of the slanted pin-fin heat exchangers, such as the volume and area goodness factors, were summarized and compared with the baseline plate-fin type heat exchanger quantitatively.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.1
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• pp.35-39
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• 2013

This paper reports numerical study results with respect to the thermal behavior of a natural convection cooled hybrid fin heat sink (HFH). The HFH consists of hybrid fins, hollow pin fins integrated with plate fins. The thermal performance of the HFH was numerically investigated by employing a commercial CFD software package and compared with that of the pin fin heat sink (PFH). Numerical study has found that array-based and mass-based heat transfer coefficients of the HFH are 12% and 37% greater than those of the PFH, respectively. Extended surface area and lighter weight may explain the better thermal performance of the HFH than the PFH.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.7
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• pp.557-570
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• 2014

The heat transfer, pressure loss, and thermal performance in a cooling channel were evaluated for various new fan-shaped pin-fin geometries using three-dimensional Reynolds-averaged Navier-Stokes equations. The turbulence was modeled using the low-Reynolds-number SST turbulence model in the Reynolds number range of 5,000-100,000. The numerical results for the area-averaged Nusselt numbers were validated by comparing them with the experimental data under the same conditions. A parametric study for three types of fan-shaped pin-fin geometries was performed with two parameters, namely, the leading and trailing reduction angles.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.2
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• pp.224-231
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• 2011

Heating and/or cooling of the channel with pin-fin structure is a promising choice for the efficient heat transfer. Complex pin-fin structure shows highly irregular behavior like porous media. This study shows the numerical analysis on the characteristic of heat transfer and pressure drop of a channel with pin-fin structure. It predicts the experimental data quite well at the high porosity region with large diameter. Low porosity activates the rigorous flow disturbance and, consequently, the enhanced heat transfer. However, the concept of optimum design should be carefully reviewed because the pressure drop is also increased with decreasing porosity at low porosity region.