Impingement of Axisymmetric Under-Expanded Sonic Jets on a Flat Plate

2002 ◽  
Author(s):  
Byung Gi Kim ◽  
Man Sun Yu ◽  
Hyung Hee Cho ◽  
Ki Young Hwang ◽  
Joo Chan Bae
Keyword(s):  
Heat Transfer ◽  
Flat Plate ◽  
Nozzle Exit ◽  
Ambient Pressure ◽  
Expansion Ratio ◽  
Recovery Factor ◽  
Heat Transfer Characteristics ◽  
Sonic Jet ◽  
Plate Distance ◽  
Parameters Of Interest

An experimental investigation has been carried out to examine heat transfer characteristics of an axisymmetric, under-expanded, and sonic jet impinging on a flat plate. Distributions of recovery factor and the surface pressure on the flat plate have been obtained in detail. The ratio of nozzle exit pressure to the ambient pressure, i.e., under-expansion ratio ranges from 1.5 to 3.5 and the nozzle-to-plate distance is tested from 0.5 to 20.0 nozzle exit diameters. It has been found that the recovery factor varies from 0.35 up to over 1.25 depending on both parameters of interest within the present experimental range.

Heat Transfer Characteristics of a Pair of Impinging Rectangular Flame Jets

2003 ◽  
Vol 125 (6) ◽  
pp. 1140-1146 ◽  
Author(s):  
L. L. Dong ◽  
C. W. Leung ◽  
C. S. Cheung
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Reynolds Number ◽  
Flat Plate ◽  
Effective Diameter ◽  
Heat Transfer Characteristics ◽  
Average Heat ◽  
Transfer Characteristics ◽  
Premixed Laminar ◽  
Plate Distance

Experiments were carried out to study the heat transfer characteristics of a pair of premixed, laminar, rectangular, butane/air flame jets impinging vertically upon a water-cooled flat plate. The effects of jet-to-jet spacing and the nozzle-to-plate distance on heat transfer were examined. The Reynolds number of the exit flow was 800. The non-dimensional jet-to-jet spacing ranged from 0.9 to 4.1, while the non-dimensional nozzle-to-plate distance varied from 1 to 6. The between-jet interference decreased with increasing jet-to-jet spacing and nozzle-to-plate distance. Both the maximum local and average heat flux occurred at a moderate jet-to-jet spacing of twice effective nozzle diameter, and when the nozzle-to-plate distance was equal to the effective diameter of the nozzle. The heat flux decreased faster along the shorter sides of the slot jets than the longer sides.

Jet-to-Plate Distance Effect on Heat Transfer From a Flat Plate to an Impinging Jet at Various Reynolds Numbers

2012 ◽  
Author(s):  
Patricia Streufert ◽  
Terry X. Yan ◽  
Mahdi G. Baygloo
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Reynolds Number ◽  
Flat Plate ◽  
Numerical Solutions ◽  
Stokes Equations ◽  
Local Heat Transfer ◽  
Reynolds Numbers ◽  
Air Jet ◽  
Plate Distance

Local turbulent convective heat transfer from a flat plate to a circular impinging air jet is numerically investigated. The jet-to-plate distance (L/D) effect on local heat transfer is the main focus of this study. The eddy viscosity V2F turbulence model is used with a nonuniform structured mesh. Reynolds-Averaged Navier-Stokes equations (RANS) and the energy equation are solved for axisymmetric, three-dimensional flow. The numerical solutions obtained are compared with published experimental data. Four jet-to-plate distances, (L/D = 2, 4, 6 and 10) and seven Reynolds numbers (Re = 7,000, 15,000, 23,000, 50,000, 70,000, 100,000 and 120,000) were parametrically studied. Local and average heat transfer results are analyzed and correlated with Reynolds number and the jet-to-plate distance. Results show that the numerical solutions matched experimental data best at low jet-to-plate distances and lower Reynolds numbers, decreasing in ability to accurately predict the heat transfer as jet-to-plate distance and Reynolds number was increased.

Heat Transfer Characteristics of Impinging Two-Dimensional Air Jets

1966 ◽  
Vol 88 (1) ◽  
pp. 101-107 ◽  
Author(s):  
Robert Gardon ◽  
J. Cahit Akfirat
Keyword(s):  
Heat Transfer ◽  
Flat Plate ◽  
Two Dimensional ◽  
Heat Transfer Characteristics ◽  
Transfer Coefficients ◽  
Average Heat ◽  
Heat Transfer Coefficients ◽  
Transfer Characteristics ◽  
Air Jets

Local as well as average heat transfer coefficients between an isothermal flat plate and impinging two-dimensional jets were measured for both single jets and arrays of jets. For a large and technologically important range of variables the results have been correlated in relatively simple terms, and their application to design is briefly considered.

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