Heat-transfer enhancement and pressure loss by surface roughness in turbulent channel flows

Katoh, Kenji; Choi, Kwing-So; Azuma, Tsuneo

doi:10.1016/s0017-9310(00)00033-8

Cited by 27 publications

(11 citation statements)

References 22 publications

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“…[1][2][3][4][5][6][7][8][9][10] However, the effect of orifice surface roughness on liquid weeping in bubble columns is not available in the literature, though surface roughness has already been found to affect numerous scientific and engineering applications. [11][12][13][14][15][16][17][18][19][20] It has been reported in our previous study that a bubble and liquid weeping cycle can be classified into four stages: bubbling, gas-liquid interface movement, weeping, and bridging. 5 As shown in Figure 1, the plenum pressure decreases in the bubbling stage because of the expansion of gas during bubble growth.…”

Section: Introductionmentioning

confidence: 99%

Effect of Orifice Surface Roughness on the Liquid Weeping in Bubble Columns

Hossain

Pang

et al. 2010

Ind. Eng. Chem. Res.

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Liquid weeping at the orifices of a gas distributor plate is one problem commonly encountered in bubble column operations. The effect of orifice surface roughness on the liquid weeping phenomenon in a bubble column is investigated over a superficial orifice gas velocity range of 143−703 cm/s. High-speed images of the bubbling and liquid weeping process are analyzed using a computer-aided image analysis algorithm. Pressure fluctuation in the plenum is also monitored. The liquid weeping rate is found to decrease with an increase in orifice surface roughness at low superficial orifice gas velocities while it increases with an increase in surface roughness at high superficial orifice gas velocities. Analysis indicates that the orifice surface roughness affects liquid weeping indirectly by changing the bubbling behaviors at the orifice. At low superficial orifice gas velocities, an increase in orifice surface roughness reduces the bubble size at bubble detachment. The reduction in pressure fluctuation in the plenum thus decreases the liquid weeping rate. On the other hand, as the superficial orifice gas velocity is approaching the bubbling/jetting regime transition, an increase in orifice surface roughness increases the transition velocity and hence the liquid weeping rate increases. Nonetheless, a modification of the orifice surface roughness is a viable solution to the liquid weeping problem in industrial bubble columns.

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Section: Introductionmentioning

confidence: 99%

Effect of Orifice Surface Roughness on the Liquid Weeping in Bubble Columns

Hossain

Pang

et al. 2010

Ind. Eng. Chem. Res.

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“…Much effort has gone into ways to reduce friction energy loss and to control fluid flow close to pipe wall. And in the fields of heat transfer, where space can be limited, size together with efficient heat transfer capabilities are extremely important, grooves meet both of these criteria, as studied by [1,2,3]. In the application of fluid flow which actually turbulence, here grooves can have a significant effect, as well as on viscous areas near pipe walls reported by [4,5,6].…”

Section: Introductionmentioning

confidence: 99%

Flow behavior and friction factor in internally grooved pipe wall

Sunu¹,

Wardana²,

Sonief³

et al. 2014

astp

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“…Over the years, many researches on the fluid flow through the grooves and corrugated tubes and their influence on the heat transfer characteristics have been carried out [21][22][23][24][25][26][27][28]. Although many researches have focused on the groove's shape and the flow structure correlated to a heat transfer enhancement on various applications, few have been done on the annulus of the heat exchanger.…”

Section: Introductionmentioning

confidence: 99%

Heat Transfer Enhancement and Pressure Drop of Grooved Annulus of Double Pipe Heat Exchanger

Sunu¹,

Rasta²

2017

Acta Polytech

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Abstract. This investigation was performed to experimentally investigate the enhancement of heat transfer and the friction of an annulus in a double pipe heat exchanger system with rectangular grooves in the turbulent flow regime. The shell is made of acrylic and its diameter is 28 mm. The tube is made of aluminium and its diameter is 20 mm. Grooves were incised in the annulus room with a circumferential pattern, with a groove space of 2 mm, a distance between the grooves of 8 mm and a groove height of 0.3 mm. The experiments consist of temperature and pressure measurement and a flow visualization. Throughout the investigation, the cold fluid flowed in the annulus room. The Reynold number of cold fluid varied from about 31981 to 43601 in a counter flow condition. The volume flow rate of hot fluid remains constant with Reynold number about 30904. Result showed the effect of grooves, which are applied in the annulus room. The grooves induce the pressure drop, the pressure drop in the grooved annulus was greater by about 15.88 % to 16.72 % than the one in the smooth annulus. The total heat transfer enhancement is of 1.09-1.11. Moreover, the use of grooves in the annulus of the heat exchanger not only increase the heat transfer process, but also increase the pressure drop, which is related to the friction factor.

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Heat-transfer enhancement and pressure loss by surface roughness in turbulent channel flows

Cited by 27 publications

References 22 publications

Effect of Orifice Surface Roughness on the Liquid Weeping in Bubble Columns

Effect of Orifice Surface Roughness on the Liquid Weeping in Bubble Columns

Flow behavior and friction factor in internally grooved pipe wall

Heat Transfer Enhancement and Pressure Drop of Grooved Annulus of Double Pipe Heat Exchanger

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