Experimental Research on Heat Transfer Enhancement for High Prandtl-Number Fluid

2005 ◽  
Vol 47 (3) ◽  
pp. 569-573 ◽  
Author(s):  
Shin-ya Chiba ◽  
Masahiro Omae ◽  
Kazuhisa Yuki ◽  
Hidetoshi Hashizume ◽  
Saburo Toda ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Prandtl Number ◽  
Heat Transfer Enhancement ◽  
Experimental Research ◽  
Transfer Enhancement ◽  
High Prandtl Number

Numerical research on heat transfer enhancement for high Prandtl-number fluid

2006 ◽  
Vol 81 (1-7) ◽  
pp. 513-517 ◽  
Author(s):  
Shin-Ya Chiba ◽  
Kazuhisa Yuki ◽  
Hidetoshi Hashizume ◽  
Saburo Toda ◽  
Akio Sagara
Keyword(s):  
Heat Transfer ◽  
Prandtl Number ◽  
Heat Transfer Enhancement ◽  
Transfer Enhancement ◽  
High Prandtl Number ◽  
Numerical Research

Heat Transfer Enhancement in Narrow Channels Using Two and Three-Dimensional Mixing Devices

1995 ◽  
Vol 117 (3) ◽  
pp. 590-596 ◽  
Author(s):  
S. V. Garimella ◽  
D. J. Schlitz
Keyword(s):  
Heat Transfer ◽  
Heat Source ◽  
Prandtl Number ◽  
Heat Transfer Enhancement ◽  
Large Scale ◽  
Three Dimensional ◽  
Reynolds Numbers ◽  
Transitional Flow ◽  
Transfer Enhancement ◽  
Roughness Elements

The localized enhancement of forced convection heat transfer in a rectangular duct with very small ratio of height to width (0.017) was experimentally explored. The heat transfer from a discrete square section of the wall was enhanced by raising the heat source off the wall in the form of a protrusion. Further enhancement was effected through the use of large-scale, three-dimensional roughness elements installed in the duct upstream of the discrete heat source. Transverse ribs installed on the wall opposite the heat source provided even greater heat transfer enhancement. Heat transfer and pressure drop measurements were obtained for heat source length-based Reynolds numbers of 2600 to 40,000 with a perfluorinated organic liquid coolant, FC-77, of Prandtl number 25.3. Selected experiments were also performed in water (Prandtl number 6.97) for Reynolds numbers between 1300 and 83,000, primarily to determine the role of Prandtl number on the heat transfer process. Experimental uncertainties were carefully minimized and rigorously estimated. The greatest enhancement in heat transfer relative to the flush heat source was obtained when the roughness elements were used in combination with a single on the opposite wall. A peak enhancement of 100 percent was obtained at a Reynolds number of 11,000, which corresponds to a transitional flow regime. Predictive correlations valid over a range of Prandtl numbers are proposed.

Experimental Research of Supercritical Water Heat Transfer in Different Channels

2013 ◽  
Author(s):  
Hong-bo Li ◽  
Meng Zhao ◽  
Han-yang Gu ◽  
Fei Wang ◽  
Jian-min Zhang ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Flow Velocity ◽  
Critical Point ◽  
Heat Transfer Enhancement ◽  
Experimental Research ◽  
Supercritical Water ◽  
Annular Channel ◽  
Fluid Temperature ◽  
Transfer Enhancement ◽  
Low Mass

The experimental research of supercritical water heat transfer has been performed on the supercritical water multipurpose test loop (SWAMUP) with tube, annular channel, and bundles. The normal heat transfer, heat transfer deterioration (HTD) and heat transfer enhancement were observed; and the heat transfer experimental data were obtained. The experimental results show that: the first kind of HTD caused by buoyancy effect only occurs with low mass flow velocity and high heat flux when the fluid temperature is below pseudo-critical point in all the tested channels and the second kind of HTD caused by acceleration effect always occurs when the fluid temperature reaches pseudo-critical point in tube and annular channel; the heat transfer enhancement occurs when the fluid temperature reaches pseudo-critical point with low mass flow velocity in tube; and the heat transfer enhancement in bundles is caused by the space grids. It is concluded that the heat transfer in bundles is better than in other tested channels.

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