Nanoscale heat transfer investigation of an array of impinging jet systems with different working fluids under crossflow with and without pin fins

Heat Transfer ◽  
2020 ◽  
Vol 50 (1) ◽  
pp. 81-104
Author(s):  
Usman Allauddin ◽  
Rafay Mohiuddin ◽  
Hafiz Mohammad Usman Khan ◽  
Naseem Uddin ◽  
Waqar A. Khan
Keyword(s):  
Heat Transfer ◽  
Impinging Jet ◽  
Working Fluids ◽  
Nanoscale Heat Transfer ◽  
Pin Fins

Heat transfer enhancement from micro pin fins subjected to an impinging jet

2012 ◽  
Vol 55 (1-3) ◽  
pp. 413-421 ◽  
Author(s):  
Sidy Ndao ◽  
Hee Joon Lee ◽  
Yoav Peles ◽  
Michael K. Jensen
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Enhancement ◽  
Impinging Jet ◽  
Transfer Enhancement ◽  
Pin Fins ◽  
Micro Pin Fins

Effect of Variation of Pin-fin Height on Jet Impingement Heat Transfer on a Rotating Surface

2021 ◽  
Author(s):  
Pratik S. Bhansali ◽  
Srinath V. Ekkad
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Nusselt Number ◽  
Gas Turbine ◽  
Average Nusselt Number ◽  
Jet Impingement ◽  
Impinging Jet ◽  
Rotating Disc ◽  
Disc Surface ◽  
Pin Fins

Abstract Heat transfer over rotating surfaces is of particular interest in rotating machinery such as gas turbine engines. The rotation of the gas turbine disc creates a radially outward flow on the disc surface, which may lead to ingress of hot gases into the narrow cavity between the disc and the stator. Impingement of cooling jet is an effective way of cooling the disc and countering the ingress of the hot gases. Present study focusses on investigating the effect of introducing pin-fins over the rotating disc on the heat transfer. The jet Reynolds number has been varied from 5000 to 18000, and the rotating Reynolds number has been varied from 5487 to 12803 for an aluminum disc of thickness 6.35mm and diameter 10.16 cm, over which square pins have been arranged in an inline fashion. Steady state temperature measurements have been taken using thermocouples embedded in the disc close to the target surface, and area average Nusselt number has been calculated. The effects of varying the height of the pin-fins, distance between nozzle and the disc surface and the inclination of the impinging jet with the axis of rotation have also been studied. The results have been compared with those for a smooth aluminum disc of equal dimensions and without any pin-fins. The average Nusselt number is significantly enhanced by the presence of pin fins. In the impingement dominant regime, where the effect of disc rotation is minimal for a smooth disc, the heat transfer increases with rotational speed in case of pin fins. The effect of inclination angle of the impinging jet is insignificant in the range explored in this paper (0° to 20°).

Application and Design of Multi-Impingement Cooling Channel in Turbine Blade Trail Edge

2020 ◽  
Vol 37 (3) ◽  
pp. 241-256
Author(s):  
Longfei Wang ◽  
Fengbo Wen ◽  
Songtao Wang ◽  
Xun Zhou ◽  
Zhongqi Wang
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Impinging Jet ◽  
Surface Heat ◽  
Cooling Channel ◽  
Plate Surface ◽  
Impingement Cooling ◽  
Surface Heat Transfer ◽  
Pin Fins

AbstractThe numerical simulations are used to conduct the comparative study of pin-fins cooling channel and multi-impingement cooling channel on the heat transfer and flow, and to design the multi-impingement channel through the parameters of impinging distance and impingement-jet-plate thickness. The Reynolds number ranges from 1e4 to 6e4. The dimensionless impinging distance is 0.60, 1.68, 2.76, respectively, and the dimensionless impinging-jet-thickness is 0.5, 1.0, 1.5, respectively. The endwall surface, pin-fins surface, impinging-jet-plate surface are the three object surfaces to investigate the channel heat transfer performance. The heat transfer coefficient $h$ and augmentation factor $Nu/N{u_0}$ are selected to measure the surface heat transfer, and the friction coefficient $f$ is chosen to evaluate the channel flow characteristics. The impinging-jet-plate surface owns higher heat transfer coefficient and larger area than pin-fins surface, which are the main reasons to improve the heat transfer performance of multi-impingement cooling channel. Reducing the impinging distance can improve the endwall surface heat transfer obviously and enhance impingement plate surface heat transfer to some extent, decreasing the thickness of impinging-jet-plate can significantly increase its own heat transfer coefficient, which both all increase the cooling air flow loss.

Performance enhancement of an impinging jet system using different working fluids-A numerical study

2020 ◽  
Author(s):  
Usman Allauddin ◽  
Shaiza Salahuddin ◽  
Muhammad Uzair
Keyword(s):  
Performance Enhancement ◽  
Numerical Study ◽  
Impinging Jet ◽  
Working Fluids

Experimental Study of Heat Transfer from Impinging Jet with Upstream and Downstream Crossflow

2010 ◽  
Vol 41 (8) ◽  
pp. 889-900 ◽  
Author(s):  
Daniel Thibault ◽  
Matthieu Fenot ◽  
Gildas Lalizel ◽  
Eva Dorignac
Keyword(s):  
Heat Transfer ◽  
Experimental Study ◽  
Impinging Jet

Augmented Heat Transfer of an Internal Blade Tip by Full or Partial Arrays of Pin-Fins

2011 ◽  
Vol 42 (1) ◽  
pp. 65-81 ◽  
Author(s):  
Gongnan Xie ◽  
Bengt Sunden ◽  
Lieke Wang ◽  
Esa Utriainien
Keyword(s):  
Heat Transfer ◽  
Pin Fins ◽  
Blade Tip
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