Numerical Investigation of Confined Multiple-Jet Impingement Cooling Over A Flat Plate at Different Crossflow Orientaions

2009 ◽  
Vol 55 (11) ◽  
pp. 1019-1050 ◽  
Author(s):  
Jr-Ming Miao ◽  
Chen-Yuan Wu ◽  
Ping-Hei Chen
Keyword(s):  
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.

Experimental Study of Air Slot Jet Impingement Cooling From Cylinder Placed on a Flat Plate

2019 ◽  
Vol 12 (4) ◽  
Author(s):  
Ketan Atulkumar Ganatra ◽  
Dushyant Singh
Keyword(s):  
Heat Transfer ◽  
Experimental Study ◽  
Nusselt Number ◽  
Flat Plate ◽  
Local Nusselt Number ◽  
Jet Impingement ◽  
Maximum Error ◽  
Constant Heat Flux ◽  
Impingement Cooling ◽  
Heated Cylinder

Abstract The experimental study for air slot jet impingement cooling from the heated cylinder is carried out. The heated cylinder is placed on a flat plate. The flat plate has an effective dimension as plate length (P) from heat transfer point of view. The heating of the cylindrical surface is done by providing a constant heat flux. The various parameters which affect the heat transfer from the cylinder are ReD, h/S, S/D, and P/D. The range of the parameters considered are ReD = 10,000–25,000, h/S = 4–12, S/D = 0.072–0.108, and P/D = 0–2. The effect of various parameters on heat transfer distribution (stagnation and local Nusselt number) from the cylinder is investigated. The local Nusselt number has a maximum value at θ = 0 deg and then it decreases upto θ = 180 deg. This trend is observed for all the parametric variations. The stagnation Nusselt number (Nustag) and local Nusselt number increases with the change of parameters as increase in ReD and S/D and decrease in h/S. However, Nustag remains independent with the change in P/D. The correlation for stagnation and mean Nusselt number is developed using regression analysis as a function of ReD, h/S, S/D, and P/D. The maximum error associated with the correlated value of Nustag and Num as compared with the experimental data is observed as ±13% and ±25%.

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