Effects of pin fin shape and configuration on the single-phase heat transfer characteristics of jet impingement on micro pin fins

2014 ◽  
Vol 70 ◽  
pp. 856-863 ◽  
Author(s):  
Sidy Ndao ◽  
Yoav Peles ◽  
Michael K. Jensen
Keyword(s):  
Heat Transfer ◽  
Single Phase ◽  
Jet Impingement ◽  
Heat Transfer Characteristics ◽  
Pin Fin ◽  
Transfer Characteristics ◽  
Pin Fins ◽  
Micro Pin Fins ◽  
Fin Shape

Numerical Investigation of an Integrated Impingement and Pin-Fin Cooling Configuration in a Wedge Duct

2014 ◽  
Author(s):  
Xiaoxing Feng ◽  
Shuqing Tian ◽  
Jiangtao Bai ◽  
Hong Zhang ◽  
Kefei Wang ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Jet Impingement ◽  
Heat Transfer Characteristics ◽  
Convergence Angle ◽  
Turbine Blade Cooling ◽  
Pin Fin ◽  
Transfer Characteristics ◽  
Nusselt Numbers ◽  
Pin Fins ◽  
Cooling Design

In the gas turbine blade cooling design, impingement insert and pin-fins arranged as an array in the trailing region are usually used to enhance the heat transfer. To investigate the heat transfer characteristics of the integrated impingement and the pin-fin cooling configuration in wedge channels, the numerical simulations with k-ε turbulence model and scalable wall function algorithm are carried out using a commercial CFD code. To reveal the factors that enhance the heat transfer in the blade internal trailing channel, heat transfer characteristics of pin-fins with impingement slot are compared with that without impingement slot. The effect of the ratio of jet impingement distance to pin-fin diameter on the heat transfer is analyzed. The convergence angle of the channel is studied. The heat transfer characteristics of the integrated impingement and pin-fin cooling configuration in the wedge channels are evaluated. The results reveal that the impinging jet enhances largely the heat transfer in the first two rows. In the studied range of L/D = 0.5∼2.0, the heat transfer of the pin-fins with impingement is about 20%∼25% higher than that without impingement. The averaged Nusselt numbers on the endwall surface, the pin surface, and the overall surfaces respectively in the wedge duct increase linearly with the increase of Reynolds number, decrease gradually with the increase of the impingement distance and increase with the increase of the convergence angle.

Single-Phase Heat Transfer in Mems-Based Pin Fin Heat Sink

2005 ◽  
Author(s):  
Ali Kosar ◽  
Yoav Peles
Keyword(s):  
Heat Transfer ◽  
Single Phase ◽  
Reynolds Numbers ◽  
Heat Fluxes ◽  
Transfer Coefficients ◽  
Pin Fin ◽  
Heat Transfer Coefficients ◽  
Nusselt Numbers ◽  
Pin Fins ◽  
Micro Pin Fins

An experimental study has been performed on single-phase heat transfer of de-ionized water over a bank of shrouded micro pin fins 243-μm long with hydraulic diameter of 99.5-μm. Heat transfer coefficients and Nusselt numbers have been obtained over effective heat fluxes ranging from 3.8 to 167 W/cm2 and Reynolds numbers from 14 to 112. The results were used to derive the Nusselt numbers and total thermal resistances. It has been found that endwalls effects are significant at low Reynolds numbers and diminish at higher Reynolds numbers.

Experimental Study on Heat Transfer Characteristics of Circular Jet Impingement Boiling on the Variety of Structured Copper Surfaces in Stagnation Zone

2016 ◽  
Author(s):  
Mayank Modak ◽  
Vishal Nirgude ◽  
Avadhesh K. Sharma ◽  
Santosh K. Sahu
Keyword(s):  
Heat Transfer ◽  
Jet Impingement ◽  
Copper Surface ◽  
Heat Transfer Characteristics ◽  
Two Phase ◽  
Copper Surfaces ◽  
Transfer Rates ◽  
Copper Target ◽  
Pin Fin ◽  
Transfer Characteristics

In the present work an attempt has been made to study the heat transfer characteristics of single circular jet on a variety of enhanced surfaces. In the present investigation three different copper target surfaces of various surface modifications: bare copper surface, pin fin enhancement surface and a flat surface coated with alumina porous layer. The heat transfer performance of each surface is studied in two phase boiling operation at different flow rates (3959 < Re < 7900). The comparison indicates that both the surface modification have enhanced the boiling heat transfer rates.

Numerical Investigation on the Flow and Heat Transfer Characteristics of the Superheated Steam in the Wedge Duct With Pin-Fins

2013 ◽  
Author(s):  
Gaoliang Liao ◽  
Xinjun Wang ◽  
Xiaowei Bai ◽  
Ding Zhu ◽  
Jinling Yao
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Nusselt Number ◽  
Three Dimensional ◽  
Heat Transfer Characteristics ◽  
Pin Fin ◽  
Transfer Characteristics ◽  
Flow And Heat Transfer ◽  
Pin Fins ◽  
Steam Superheat

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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