论文信息 - The effects of roughness types on friction factors and heat transfer in roughened rectangular duct

The effects of roughness types on friction factors and heat transfer in roughened rectangular duct

Abstract A comparison of fully developed heat transfer and friction factor characteristics has been made in rectangular ducts with ones roughened by five different shapes. The effects of rib shape geometries and Reynolds numbers are examined. The rib height-to-duct hydraulic diameter, pitch-to-height ratio, and aspect ratio of channel width to height are fixed at e/De = 0.0476, P / e = 8, and W /H = 2.33, respectively. To understand the mechanisms of the heat transfer enhancements, the measurements of the friction factors are also conducted in the smooth and rough channels. The data indicates that the triangular type rib has a substantially higher heat transfer performance than any other ones in the range we studied.

Soo Whan Ahn | S. Ahn

[1] K. Hijikata,et al. Fundamental study of heat transfer augmentation of tube inside surface by cascade smooth surface-turbulence promoters , 1987 .

[2] Je-Chin Han,et al. An investigation of heat transfer and friction for rib-roughened surfaces , 1978 .

[3] R. J. Goldstein,et al. Heat transfer and friction in tubes with repeated-rib roughness , 1971 .

[4] J. Whitelaw,et al. Convective heat and mass transfer , 1966 .

[5] Jenn-Jiang Hwang,et al. Heat transfer-friction characteristic comparison in rectangular ducts with slit and solid ribs , 1998 .

[6] S. Hsieh,et al. Heat Transfer and Friction Factor Measurements in Ducts With Staggered and In-Line Ribs , 1993 .

[7] T. Rabas,et al. Disruption shape effects on the performance of enhanced tubes with the separation and reattachment mechanism , 1992 .

[8] B. Sundén. Enhancement of Convective Heat Transfer in Rib-roughened Rectangular Ducts , 1999 .

[9] D. Dipprey,et al. An experimental investigation of heat and momentum transfer in smooth and rough tubes at various Prandtl numbers , 1961 .