Heat transfer of cylindrical bodies when a system of round jets flows over them

1979 ◽  
Vol 37 (5) ◽  
pp. 1259-1261
Author(s):  
N. I. Syromyatnikov ◽  
L. K. Vasanova ◽  
V. I. Bader ◽  
A. M. Koryakin
Keyword(s):  
Heat Transfer ◽  
Round Jets

Numerical study of the oscillation amplitude effect on the heat transfer of oscillatory impinging round jets

2020 ◽  
Vol 79 (2) ◽  
pp. 70-82
Author(s):  
Saeed Jahangiri ◽  
Amir Hossein Shiravi ◽  
Mostafa Hosseinalipour ◽  
Arun S. Mujumdar
Keyword(s):  
Heat Transfer ◽  
Numerical Study ◽  
Oscillation Amplitude ◽  
Round Jets

Gas Turbine Blade Heat Transfer Augmentation by Impingement of Air Jets Having Various Configurations

1972 ◽  
Vol 94 (1) ◽  
pp. 51-58 ◽  
Author(s):  
W. Tabakoff ◽  
W. Clevenger
Keyword(s):  
Heat Transfer ◽  
Turbine Blade ◽  
Leading Edge ◽  
Solid Particles ◽  
Turbine Blade Cooling ◽  
Round Jets ◽  
Blade Cooling ◽  
Heat Transfer Augmentation ◽  
Air Jets ◽  
Mass Flow Rates

An experimental investigation of heat transfer characteristics for various configurations of air jets impinging on the leading edge inner surface of the blade wall is presented. Three configurations were investigated, namely a slot jet, a round jet row and an array of round jets. The effect on the heat transfer coefficient of injecting solid particles into the air flow is considered. The study treats an important class of turbine blade cooling for which small cooling mass flow rates are of interest. The experimental facility and procedures are described in detail. A theoretical technique is introduced for predicting the heat transfer in the case of the slot jet configuration. The results are compared to experimental data.

Heat transfer to impinging round jets with triangular tabs

2003 ◽  
Vol 46 (14) ◽  
pp. 2557-2569 ◽  
Author(s):  
N Gao ◽  
H Sun ◽  
D Ewing
Keyword(s):  
Heat Transfer ◽  
Round Jets

Experimental Investigation of the Heat Transfer Performance of Arrays of Round Jets With Sharp-Edged Orifices and Peripheral Effluent: Convective Behavior of Water on a Heated Silicon Surface

2005 ◽  
Author(s):  
Levi A. Campbell ◽  
Michael J. Ellsworth ◽  
Madhusudan Iyengar ◽  
Robert Simons ◽  
Richard Chu
Keyword(s):  
Heat Transfer ◽  
Data Reduction ◽  
Silicon Surface ◽  
Heated Surface ◽  
Orifice Diameter ◽  
Plate Height ◽  
Round Jets ◽  
Heated Area ◽  
Data Reduction Technique ◽  
Effective Heat Transfer Coefficient

In the present work, deionized water is impinged onto a heated silicon surface using square arrays of round jets. Various numbers of jets and jet diameters are used over a heated area of constant size with the orifice plate height above the heater held constant. In these experiments, the jet orifices are sharp-edged and the fluid exhaust direction is parallel to the heated surface and leaves the chip periphery through a manifold. The resulting temperature and flow data are presented in physical units as well as in groups of dimensionless parameters. A correlation is presented to reasonably predict the experimental results of this study. The techniques used for data reduction and for experimentation, including the construction of the test module, are given in detail, including a numerical conduction simulation based data reduction technique and uncertainty analysis. The results shown include flow rates ranging from 6.1 cc/s to 63.18 cc/s resulting in Reynolds numbers based on orifice diameter ranging from 141 to 6670. Jet diameters investigated in this study range from 377 μm to 1.01 mm, in square arrays of 16 to 324 orifices on an area of 18.52 mm × 18.59 mm. The resulting maximum spatially averaged effective heat transfer coefficient achieved is 7.94 W/cm2K, and the maximum spatially averaged Nusselt number based on jet diameter is 79.4.

Heat Transfer and Pressure Investigation of Dimple Impingement

2007 ◽  
Vol 130 (1) ◽  
Author(s):  
K. Kanokjaruvijit ◽  
R. F. Martinez-Botas
Keyword(s):  
Heat Transfer ◽  
Total Pressure ◽  
Static Pressure ◽  
Flat Surface ◽  
Target Plate ◽  
Round Jets ◽  
Plate Spacing ◽  
Parametric Effects ◽  
Wetted Area ◽  
Plate Geometry

Heat transfer and pressure results of an inline array of round jets impinging on a staggered array of dimples are reported with the consideration of various geometric and parametric effects; results are normalized against flat plate data. The heat transfer was measured by using transient wideband liquid crystal method. The geometrical configurations considered were crossflow (or spent-air exit) scheme, dimple geometries, and impinging positions. Three crossflow schemes were tested such as one-way, two-way, and free exits. These led to the idea of the coupling effects of impingement and channel flow depending on which one dominated. Hemispherical and cusped elliptical dimple shapes with the same wetted area were considered and found that both dimples showed the similarity in heat transfer results. Impinging positions on dimples and on flat portions adjacent to dimples were examined. Throughout the study, the pitch of the nozzle holes was kept constant at four jet diameters. The investigated parameters were Reynolds number (ReDj) ranged from 5000 to 11,500, jet-to-plate spacing (H∕Dj) varied from 1 to 12 jet diameters, dimple depths (d∕Dd) of 0.15, 0.25, and 0.29, and dimple curvature (Dj∕Dd) of 0.25, 0.50, and 1.15. The shallow dimples (d∕Dd=0.15) improved heat transfer significantly by 70% at H∕Dj=2 compared to that of the flat surface, while this value was 30% for the deep ones (d∕Dd=0.25). The improvement also occurred to the moderate and high Dj∕Dd. The total pressure was a function of ReDj and H∕Dj when H∕Dj<2, but it was independent of the target plate geometry. The levels of the total pressure loss of the dimpled plates werenot different from those of the flat surface under the same setup conditions. Wall static pressure was measured by using static taps located across each plate. ReDj and H∕Dj affected the level of the static pressure while the dimple depth influenced the stagnation peaks, and the crossflow scheme affected the shape of the peaks.

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