scholarly journals Experimental Investigation on Impingement Heat Transfer From Rib Roughened Surface Within Arrays of Circular Jet: Effect of Geometric Parameters

1998 ◽  
Author(s):  
Chang Haiping ◽  
Zhang Jingyu ◽  
Huang Taiping
Keyword(s):  
Heat Transfer ◽  
Flux Ratio ◽  
Hole Diameter ◽  
Geometric Parameters ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics ◽  
Impingement Heat Transfer ◽  
Roughened Surface ◽  
Turbine Airfoils ◽  
Rib Roughened

Impingement heat transfer from rib roughened surface within two-dimensional arrays of circular jet with initial crossflow has been investigated experimentally. The configurations considered are intended to simulate the impingement cooled midchord region of the gas turbine airfoils in case where an initial crossflow is present. Many factors affect the heat transfer. The relative positions of the jet hole to the ribs and the geometric parameters have the significant effect on the heat transfer characteristics and have been experimentally studied. The investigation on the effect of the relative position of the jet hole to the ribs has been presented in an other paper. The effects of the geometric parameters such as jet hole spacing, jet-to-surface spacing, rib pitch-to-height ratio and rib height-to-hole diameter ratio on the heat transfer characteristics are considered in this paper. The experimentation is conducted under the conditions of Reynolds number 7,000–15,000 and the crossflow-to-jet mass flux ratio based on each channel/jet hole area 0∼0.5. With three jet hole spacing to jet hole diameter ratios, five jet-to-surface spacings, three rib pitch-to-height ratios and three rib height-to-hole diameter ratios, a great number of experimental data has been obtained. Based on this, the effects of the geometric parameters on the heat transfer characteristics have been obtained qualitatively and quantitatively. It can be used for evaluating the efficiency of the impingement heat transfer.

Experimental Investigation on Impingement Heat Transfer From Rib Roughened Surface Within Arrays of Circular Jets: Correlation

2000 ◽  
Author(s):  
Haiping Chang ◽  
Jingyu Zhang ◽  
Taiping Huang
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Guide Vane ◽  
Turbine Blades ◽  
Leading Edge ◽  
Target Surface ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics ◽  
Impingement Heat Transfer ◽  
Rib Roughened

Impingement heat transfer is one of the useful cooling methods for high temperature gas turbine blades and/or guide vanes in aeroengines. After the cooling jet impinges on the leading edge of the turbine blade and/or guide vane, it flows downstream and turns to be the initial crossflow for the aft row of impinging jet. The process of impingement heat transfer is quite complicated, especially when the target surface is rib roughened. In this paper, the correlation of the impingement heat transfer characteristics has been analyzed based on thousands of experimental data in different parameter matching conditions (Ref = 7000∼20000, Gc/Gj = 0∼0.5, Xn = 5∼15, Zn = 1.5∼5, p/e = 5∼12 and e/d = 0.5∼1.5). The impingement heat transfer characteristics can be generally expressed as a functional formulation with the exponential functions of Ref, Zn, Xn, e/d and p/e, and a polynomial function of Gc/Gj. The interaction among the parameters are reflected in the exponents i, j, k, n, etc. and the weighing coefficients. By the regression processing to the experimental data, the exponents and the weighing coefficients are determined. The correlation equation of impingement heat transfer characteristics to the parameters has been finally concluded. Comparison shows that the correlation results are in good agreement with the experimental data.

Impingement Heat Transfer Characteristics by Triangular Orifice Jet

2002 ◽  
Vol 2002 (0) ◽  
pp. 499-500
Author(s):  
Shinichi KUNIEDA ◽  
Munehiko HIWADA ◽  
Junji MIMATSU ◽  
Shinji SAKAI ◽  
Kouzou TANAKA ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics ◽  
Impingement Heat Transfer

Heat Transfer Characteristics for Inline and Staggered Arrays of Circular Jets with Crossflow of Spent Air

1979 ◽  
Vol 101 (3) ◽  
pp. 526-531 ◽  
Author(s):  
D. E. Metzger ◽  
L. W. Florschuetz ◽  
D. I. Takeuchi ◽  
R. D. Behee ◽  
R. A. Berry
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Heat Transfer Surface ◽  
Geometric Parameters ◽  
Channel Height ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics ◽  
Nusselt Numbers ◽  
Circular Jets ◽  
Impinging Flow

Heat transfer characteristics were measured for two-dimensional arrays of jets impinging on a surface parallel to the jet orifice plate. The impinging flow was constrained to exit in a single direction along the channel formed by the jet plate and the heat transfer surface. Both mean Nusselt numbers and streamwise Nusselt number profiles are presented as a function of Reynolds number and geometric parameters. The results show that significant periodic variations occur in the streamwise Nusselt number profiles, persisting downstream for at least ten rows of jet holes. Both channel height and hole spacing can have a significant effect on the streamwise profiles, smoothed across the periodic variations. Where significant differences exist, inline hole patterns provide better heat transfer than staggered ones, particularly downstream. These and other effects of the geometric parameters are presented and discussed.

Heat Transfer Characteristics of CuO-Water Nanofluids Jet Impingement on a Hot Surface

2016 ◽  
Author(s):  
Sandesh S. Chougule ◽  
Mayank Modak ◽  
Prajakta D. Gharge ◽  
S. K. Sahu
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Jet Impingement ◽  
Target Surface ◽  
Test Surface ◽  
Initial Surface ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics ◽  
Impingement Heat Transfer ◽  
Hot Surface

In present study, an experimental investigation has been carried out to analyze the heat transfer characteristics of CuO-water nanofluids jets on a hot surface. A rectangular stainless steel foil (AISI-304, 0.15 mm thick) is used as a test surface is electrically heated to obtain the required initial temperature. The distribution of heat flux on the target surface is evaluated from the recorded thermal images during transient cooling. The effect of nanoparticle concentration and Reynolds number of the nanofluids jet impingement heat transfer characteristics is studied. Tests were performed for an initial surface temperature of 500°C, Reynolds number (5000≤Re≤13000), CuO-water nanofluids concentration (Φ= 0.15%, 0.6%) and nozzle to plate distance was l/d= 4.

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