Heat Transfer Characteristics of an Endwall with Single Row of Oblique Pin Fins

By using the CFX software, the three-dimensional flow and heat transfer characteristics in the cooling duct with pin-fin in the blade trailing edge were numerically simulated. The effects of pin-fin arrangements, Reynolds number, steam superheat degrees, streamwise pin density and convergence angle of the wedge duct on the flow and heat transfer characteristics were analysed. The results show that the Nusselt number on the endwall and pin-fin surfaces as well as the pin-fin row averaged Nusselt number increase with the increasing of Reynolds number, while it decreased with the with the increasing of X/D. The pressure drop increases with the increasing of Reynolds number while decreases with the increasing of X/D in the wedge duct. The degree of superheat has little effect on the pressure loss in the wedge duct. A comprehensive analysis and comparison show that the highest thermal performance is reached in the wedge duct when the value of X/D is 1.5.

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The Flow Resistance and Heat Transfer Characteristics of Micro Pin-Fins with Different Cross-Sectional Shapes

Nanoscale and Microscale Thermophysical Engineering ◽

10.1080/15567265.2015.1073820 ◽

2015 ◽

Vol 19 (3) ◽

pp. 221-243 ◽

Cited By ~ 11

Author(s):

Z. G. Liu ◽

N. Guan ◽

C. W. Zhang ◽

G. L. Jiang

Keyword(s):

Heat Transfer ◽

Flow Resistance ◽

Heat Transfer Characteristics ◽

Cross Sectional ◽

Transfer Characteristics ◽

Pin Fins ◽

Micro Pin Fins

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Inaccuracy of Heat Transfer Characteristics for Pin Fins Considering the Influence of Heat Radiation

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.199-200.1513 ◽

2011 ◽

Vol 199-200 ◽

pp. 1513-1517

Author(s):

Fu Jen Wang ◽

Jung Chieh Chang ◽

Kuo Chien Lin ◽

King Leung Wong

Keyword(s):

Heat Transfer ◽

Heat Exchanger ◽

Heat Transfer Rate ◽

Transfer Rate ◽

Radiation Effect ◽

Heat Radiation ◽

Convection Coefficient ◽

Heat Transfer Characteristics ◽

Transfer Characteristics ◽

Pin Fins

Pin fins are widely applied in heat exchanger industry. The heat transfer characteristics of pin fins can be found in many textbooks and handbooks related to heat transfer or heat exchanger. However, most heat transfer experts recognized from their own experiences that the heat radiation effect equation contained the fourth order exponential of temperature and the emissivity of oxidized metal are higher, the inaccuracy of heat transfer rate might be higher while ignoring the effect of heat radiation. In this study, numerical simulation using computational fluid dynamics (CFD) code was conducted to verify the heat transfer characteristics of pin fins. It is found that the error of heat transfer rate generated by ignoring heat radiation will be as high as 45 % while heat convection coefficient is 10 (Wm-2K-1 ) associated with the emissivity of fin surface is 1.0. It also revealed the heat radiation effect cannot be neglected for pin fins, especially for the application under high emissivity and low heat convection coefficient conditions.

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