Investigation of Thermo-hydraulic Performance of Circular Tube Fitted with Center-cleared Twisted Tape Using CFD Modeling

Abstract This study is conducted to investigate the effect of off-center placement of twisted tape on flow distribution and heat transfer in a circular tube. The effect of tape width of 20, 18, 16, 14 and 12 mm on the heat transfer performance is discussed under the same twist ratio of 2.0. The numerical analysis of the flow field, average Nusselt number, friction factor and thermo-hydraulic performance parameter of the tube are discussed with Reynolds number ranged from 2600 to 8760. The results indicate that the Nusselt number of the tube fitted with center-placed twisted tapes at various width is 7~51% higher than the plain tube, and performance in low Reynolds region was found more effective than that in high Reynolds region. The heat transfer for circular tube with twisted tape attached to the wall shows better performance than that for the tube with center-placed twisted tape. With a smaller tape width, a higher increasing ratio of Nu-wall/Nu-center is obtained. The increasing ratio for Nusselt number ranged from 3 to 18%. However, the use of twisted tape inserts is not beneficial for energy saving. The thermo-hydraulic performance parameters for convective heat transfer of helium gas flowing in a circular tube are below unity for the calculated Reynolds region.

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Three-Dimensional Numerical Simulation of Thermal-Hydraulic Performance of A Circular Tube with Edgefold-Twisted-Tape Inserts

Journal of Hydrodynamics ◽

10.1016/s1001-6058(09)60101-3 ◽

2010 ◽

Vol 22 (5) ◽

pp. 662-670 ◽

Cited By ~ 28

Author(s):

Yong-zhang Cui ◽

Mao-cheng Tian

Keyword(s):

Numerical Simulation ◽

Circular Tube ◽

Three Dimensional ◽

Hydraulic Performance ◽

Twisted Tape

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The effect of off-center placement of twisted tape on flow and heat transfer characteristics in a circular tube

Scientific Reports ◽

10.1038/s41598-021-86285-0 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Li Wang ◽

Peiyong Ni ◽

Guannan Xi

Keyword(s):

Heat Transfer ◽

Nusselt Number ◽

Circular Tube ◽

Flow Distribution ◽

Hydraulic Performance ◽

Twisted Tape ◽

Twisted Tapes ◽

Plain Tube ◽

And Performance ◽

High Reynolds

AbstractThis study is conducted to investigate the effect of off-center placement of twisted tape on flow distribution and heat transfer in a circular tube. The effect of tape width of 20, 18, 16, 14 and 12 mm on the heat transfer performance is discussed under the same twist ratio of 2.0. The numerical analysis of the flow field, average Nusselt number, friction factor and thermo-hydraulic performance parameter of the tube are discussed with Reynolds number ranged from 2600 to 8760. The results indicate that the Nusselt number of the tube fitted with center-placed twisted tapes at various width is 7–51% higher than the plain tube, and performance in low Reynolds region was found more effective than that in high Reynolds region. The heat transfer for circular tube with twisted tape attached to the wall shows better performance than that for the tube with center-placed twisted tape. With a smaller tape width, a higher increasing ratio of Nu-wall/Nu-center is obtained. The increasing ratio for Nusselt number ranged from 3 to 18%. However, the use of twisted tape inserts is not beneficial for energy saving. The thermo-hydraulic performance parameters for convective heat transfer of helium gas flowing in a circular tube are below unity for the calculated Reynolds region.

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