Wall-Resolved LES and Zonal LES of Round Jet Impingement Heat Transfer on a Flat Plate

Jet impingement heat transfer on a target plate covered with a thick porous layer with or without a cylindrical center cavity is experimentally investigated using the transient liquid crystal technique. Based on the results of jet impingement on a bare flat plate, heat transfer enhancement due to the attachment of porous medium is assessed. The varying parameters in the experiments include the nozzle-to-plate distance, jet Reynolds number, jet-to-cavity diameter ratio, and the cavity depth. Results of Nusselt number distribution, stagnation-zone Nusselt number, and averaged Nusselt number over a region of 3 times the hole diameter are documented. Experimental results show that the attachment of the porous layer with a center cavity can either hamper, or effectively enhance the jet impingement heat transfer over a flat plate. The maximum enhancement occurs at jet Reynolds number of 12400 when the cavity is a through hole and the cavity has the same diameter as the jet. The stagnation-zone Nusselt number increases 58.3% and the averaged Nusselt number increases 77.5% at the maximum enhancement condition. On the other hand, the addition of the thick porous layer without a center cavity gave rise to severe adverse effect on jet impingement heat transfer.

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Numerical Investigation of Impingement Heat Transfer Enhancement on a Flat Plate with an Attached Porous Medium

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.312-315.477 ◽

2011 ◽

Vol 312-315 ◽

pp. 477-482 ◽

Cited By ~ 2

Author(s):

Pey Shey Wu ◽

Yi Wen Lo ◽

Fong Chia Cheng

Keyword(s):

Heat Transfer ◽

Porous Medium ◽

Flat Plate ◽

Numerical Models ◽

Thick Layer ◽

Jet Impingement ◽

Heat Transfer Process ◽

Heated Plate ◽

Impingement Heat Transfer ◽

Hole Geometry

The enhancement of impingement heat transfer on a flat plate covered with a thick layer of porous medium with or without a center hole was numerically investigated. The renormalization group turbulence model is selected for the fluid region while Forchheimer extended Darcy’s model is used for porous region. The numerical models were justified by comparisons with available experimental data. Computational results show that an attached porous medium with a center hole can effectively enhance jet impingement heat transfer while an attached thick porous layer without a center hole has detrimental effect. The physics of these results are supported and well explained by the detailed flow patterns. The most influential parameters in this heat transfer process include the jet Reynolds number and the center hole geometry (hole depth and jet-to-hole diameter ratio). A good hole geometry should well trap the jet and direct the coolant along the heated plate.

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Computational Study of Mist Jet Impingement Heat Transfer on a Flat Plate with Slotted Nozzle

Recent Advances in Mechanical Infrastructure - Lecture Notes in Intelligent Transportation and Infrastructure ◽

10.1007/978-981-32-9971-9_14 ◽

2019 ◽

pp. 133-141

Author(s):

Bikram Kumar Pani ◽

Dushyant Singh

Keyword(s):

Heat Transfer ◽

Flat Plate ◽

Computational Study ◽

Jet Impingement ◽

Impingement Heat Transfer

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An Experimental Study of Impingement Heat Transfer on the Surfaces With Micro W-Shaped Ribs

Volume 5B: Heat Transfer ◽

10.1115/gt2015-42573 ◽

2015 ◽

Author(s):

Yu Rao ◽

Peng Chen ◽

Jiaqi Zhu

Keyword(s):

Heat Transfer ◽

Experimental Study ◽

Flat Plate ◽

Pressure Loss ◽

Cooling System ◽

Cross Flow ◽

Jet Impingement ◽

Test Plate ◽

Plate Spacing ◽

Impingement Heat Transfer

The paper proposed an idea of using micro-W-shaped ribs on a test plate to improve the impingement heat transfer performance in a multiple-jet impingement cooling system. An experimental study has been conducted on the heat transfer characteristics of multiple-jet impingement onto a flat plate and a roughened plate with micro W-shaped ribs under maximum cross flow scheme. Transient liquid crystal thermography method has been used to obtain the detailed impingement heat transfer distribution for the Reynolds numbers from 15,000 to 30,000.The effects of micro W ribs on the local Nusselt number and the related pressure loss were investigated experimentally. The jet-to-plate spacing H/d=1.5 was used in the experiments for both the flat and the micro-W-rib roughened plate. The experiments showed that the micro W ribs on the plate can enhance the impingement heat transfer globally and locally, and increase the heat transfer uniformity, which are due to the facts that the micro W ribs on the test plate increase the near-wall turbulent mixing by interacting with the wall jets and cross flow. The pressure loss is negligibly increased compared to the impingement onto the flat plate.

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Jet impingement heat transfer on a flat plate at a constant wall temperature

International Journal of Thermal Sciences ◽

10.1016/j.ijthermalsci.2007.10.020 ◽

2008 ◽

Vol 47 (12) ◽

pp. 1610-1619 ◽

Cited By ~ 67

Author(s):

B. Sagot ◽

G. Antonini ◽

A. Christgen ◽

F. Buron

Keyword(s):

Heat Transfer ◽

Flat Plate ◽

Wall Temperature ◽

Jet Impingement ◽

Constant Wall Temperature ◽

Impingement Heat Transfer

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Reynolds Averaged and Large Eddy Computations of Flow and Heat Transfer Under Round Jet Impingement

Volume 1A, Symposia: Advances in Fluids Engineering Education; Turbomachinery Flow Predictions and Optimization; Applications in CFD; Bio-Inspired Fluid Mechanics; Droplet-Surface Interactions; CFD Verification and Validation; Development and Applications of Immersed Boundary Methods; DNS, LES, and Hybrid RANS/LES Methods ◽

10.1115/fedsm2014-21435 ◽

2014 ◽

Cited By ~ 3

Author(s):

Thangam Natarajan ◽

James Jewkes ◽

Ramesh Narayanaswamy ◽

Yongmann M. Chung ◽

Anthony D. Lucey

Keyword(s):

Heat Transfer ◽

Reynolds Number ◽

Turbulence Models ◽

Jet Impingement ◽

Navier Stokes ◽

Round Jet ◽

Eddy Simulation ◽

Impingement Heat Transfer ◽

Turbulent Statistics ◽

Large Eddy

The fluid dynamics and heat transfer characteristics of a turbulent round jet are modelled numerically using Reynolds-Averaged Navier-Stokes (RANS) and Large Eddy Simulation (LES). Meshes with varying degrees of coarseness, with both radial and axial refinements are investigated. Discretization is carried out using the finite volume method. The jet configurations are chosen to enable validation against well-established experimental jet-impingement heat-transfer studies, particularly that of Cooper et al. [1]. The Reynolds number studied is 23000. The height of discharge from the impingement wall is fixed at twice the jet diameter. The work critically examines the effect of Reynolds number, standoff distance and helps to ascertain the relative merits of various turbulence models, by comparing turbulent statistics and the Nusselt number distributions. The present work is carried out as a preliminary validation, in a wider study intended to determine the thermofluidic behaviour of jets impinging upon an oscillating surface.

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