Numerical study of boundary layer transition in flowing film evaporation on horizontal elliptical cylinder

Asbik, Mohamed; Ansari, Omar; Zeghmati, Belkacem

doi:10.1007/s00231-004-0554-0

Cited by 9 publications

(3 citation statements)

References 26 publications

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“…Peng et al [15] according to the digital image process obtained that in the same condition, the average of semi-elliptical tube is minimum, compared with the round tune and the elliptical tube of the same section circumference. Asbik et al [16] observed in their study that the decreasing ellipticity generates a noticeable reduction in the laminar sublayer and hence favors the turbulence regime. Lee et al [17] simulated the effect of obliquely dispensed angle on heat transfer of elliptical tube.…”

Section: Zhang Et Al / Desalination and Water Treatment 157 (2019mentioning

confidence: 91%

Study on liquid film thickness and flow characteristics of falling film outside an elliptical tube

Zhang¹,

Zhu²,

Q³

2019

Desalination and Water Treatment

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A three-dimensional model is applied to simulate the spreading process and thickness distribution of the liquid film outside an elliptical horizontal tube falling-film heat exchanger. Reynolds number (Re) is 187 and the counter-current air flow rates are 0, 0.1 and 0.5 m/s, respectively. The volume of fluid method is used to trace the gas-liquid interface. It is shown that falling film flow delays and the liquid film thickness increases as the gas flow rate increases. When the counter-current gas flow rate is increased to 0.5 m/s, the falling film distribution becomes uneven and local accumulation occurs. Along the circumferential direction, the liquid film velocity increases as the gas flow rate increases.

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Section: Zhang Et Al / Desalination and Water Treatment 157 (2019mentioning

confidence: 91%

Study on liquid film thickness and flow characteristics of falling film outside an elliptical tube

Zhang¹,

Zhu²,

Q³

2019

Desalination and Water Treatment

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“…Asbik et al [1] carried out a numerical study of the onset of transverse and longitudinal transitions between turbulent and laminar regimes when the liquid film is evaporated on the horizontal elliptical tube. Effect of gravity, pressure gradients, and viscous forces are considered in the numerical study but not the interfacial shear stress.…”

Section: Introductionmentioning

confidence: 99%

The CFD studies on the influence of un-wetted area on the heat transfer performance of the horizontal tube falling film evaporation

Balaji

Velraj²,

Ramanamurthy

2022

THERM SCI

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This paper discusses about the effect of un-wetted area of tube on the heat transfer performance of horizontal tube falling film evaporation. A 2D CFD model was developed to perform simulations and investigate the output and validated them with published data available in the literature. In the present study the VOF method is used to track the boundary of the liquid vapour from the contours of volume fraction. Effect of varying tube wall temperature or wall super heat (6 to 11?C) on un-wetted area, heat transfer co-efficients and mass transfer co-efficients of the circular tube were obtained from the simulation model and the results were analysed and reasons were identified and discussed here. The threshold value of wall super heat above which phase change occurs between liquid film and tube surface is identified as 6?C. Also it is noted that mass transfer rate increases and then decreases with increase of wall super heat and heat transfer co-efficient showed declining trend.

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“…The numerical results show that the minimum film thickness of noncircular tubes is less than the minimum film thickness of the circular tube and the heat transfer performance of noncircular tubes is better. Asbik et al numerically studied the boundary layer transition in flow film evaporation on a horizontal elliptical cylinder. Roques et al experimentally studied the falling film transitions on plain and enhanced tubes.…”

Section: Introductionmentioning

confidence: 99%

Experimental study of falling film flow characteristics outside shaped tubes related to a spiral‐wound heat exchanger

Liu

Sun

et al. 2019

Asia-Pacific J Chem Eng

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In this paper, the falling film flow and the effects of the marine inclination on the shell-side flow pattern outside the sinusoidal corrugated tube and the square-corrugated tube related to a spiral-wound heat exchanger are experimentally studied using n-pentane as the testing fluid. The flow field phenomenon and the film thickness are investigated with the utilization of high-speed camera technology. The results show that the critical Re of the flow regime transition of the falling film outside the square-corrugated and sinusoidal corrugated tubes is quite different from the critical Re of the flow regime transition of the falling film outside the horizontal circular tube. The tube shape has a certain impact on the falling film flow characteristics. Moreover, under the inclination conditions, the liquid column and liquid film will move toward the inclined side. The resistance ability of the inclination of the squarecorrugated tube is better than the resistance ability of the sinusoidal corrugated tube due to the dragging effect.

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Numerical study of boundary layer transition in flowing film evaporation on horizontal elliptical cylinder

Cited by 9 publications

References 26 publications

Study on liquid film thickness and flow characteristics of falling film outside an elliptical tube

Study on liquid film thickness and flow characteristics of falling film outside an elliptical tube

The CFD studies on the influence of un-wetted area on the heat transfer performance of the horizontal tube falling film evaporation

Experimental study of falling film flow characteristics outside shaped tubes related to a spiral‐wound heat exchanger

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