Numerical Investigation of Jet Impingement Cooling of a Flat Plate with Carbon Dioxide at Supercritical Pressures

2017 ◽  
Vol 39 (2) ◽  
pp. 85-97 ◽  
Author(s):  
Kai Chen ◽  
Pei-Xue Jiang ◽  
Jian-Nan Chen ◽  
Rui-Na Xu
Keyword(s):  
Carbon Dioxide ◽  
Flat Plate ◽  
Numerical Investigation ◽  
Jet Impingement ◽  
Impingement Cooling

Impingement Cooling by Multiple Asymmetric Orifice Jets

2021 ◽  
Author(s):  
Chunyu Zhang ◽  
Yanyan Liu ◽  
Taahir Bhaiyat ◽  
Sjouke Schekman ◽  
Tian Jian Lu ◽  
...  
Keyword(s):  
Reynolds Number ◽  
Flat Plate ◽  
Thermal Characteristics ◽  
Jet Impingement ◽  
Diameter Ratio ◽  
Impingement Cooling ◽  
Blunt Edge ◽  
Surrounding Fluid ◽  
Target Spacing

Abstract This study presents impingement cooling from a flat plate by multiple asymmetric jets. Such jets are discharged through blunt-edge inline orifice holes with a thickness-to-diameter ratio of t/Dj = 0.5 and a jet-to-jet spacing of T/Dj = 4.0, at the Reynolds number of 20,000. Firstly, fluidic features are established both in free exit and with impingement, at varying short target spacing (e.g., H/Dj = 4.0). Secondly, thermal characteristics of the jet impingement are elucidated. Results demonstrate that, due to a skewed incidence of the coolant stream upstream of concave orifice holes, the resulting multiple orifice jets are asymmetric and skewed relative to the orifice axis. These results mimic multiple fluidically inclined jets. However, asymmetric entrainment that takes place causes faster mixing with the surrounding fluid at rest as well as faster decay of momentum. This shows more effective cooling from a flat plate for the relatively short H/Dj range than conventional symmetric orifice and nozzle jets.

Predictions of Thermal and Hydrodynamic Characteristics of a Single Circular Micro-Jet Impinging on a Flat Plate

2008 ◽  
Author(s):  
Marcel Le´on De Paz ◽  
B. A. Jubran
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Flat Plate ◽  
Reference Model ◽  
Preliminary Investigation ◽  
Jet Impingement ◽  
Hydrodynamic Characteristics ◽  
Transfer Rates ◽  
Impingement Cooling ◽  
3 Dimensional

Jet impingement cooling remains one of the key methods in various high-end cooling applications as it can induce higher heat transfer rates. The objective of this preliminary investigation is to shed some light on micro-impingement cooling and assess the accuracy for a future 3-dimensional turbine blade model. For the purpose of this study, several micro-jet impingement cases are modeled in Gambit and iterated with Fluent. The reference model consists of a single 500μm cylindrical nozzle impinging on a constant temperature flat plate. Conducive results were found on the effects of turbulence model, Reynolds number, and H/D ratio for the Nusselt distribution on the flat plate. The Reynolds numbers iterated were: 2000, 3000, 4000, 5000, and 6000. The different H/D ratios modeled were: 6, 5, 4, 3, 2, 1. In general, it was observed that a higher Reynolds number increased the heat transfer on the plate, but the jet to target spacing had no significant impact on it. All results were validated via comparison with several published experimental data, the deviation margins indicated a good agreement.

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