Heat transfer and wetting behaviour of falling liquid films in inclined tubes with structured surfaces

Eichinger, Simon; Storch, Thomas; Grab, Thomas; Tepel, S.; Heinrich, Martin; Fieback, Tobias; Groß, Ulrich

doi:10.1016/j.applthermaleng.2021.118023

Cited by 9 publications

(3 citation statements)

References 41 publications

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“…They concluded that adding the nanoparticles into the liquid film increased the evaporation rate due to the change in thermophysical properties. Examples of other recent works in this area are studies investigating the effects of surface structure and inlet swirling flow on evaporation heat transfer and efficiency of the liquid falling film systems inside vertical tubes [24][25][26].…”

Section: Introductionmentioning

confidence: 99%

A Two-Phase Sharp-Interface Numerical Model of Falling Film Thermal Desalination in a Vertical Channel

Tohidi,

Ormiston

2024

Preprint

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A two-dimensional, sharp-interface two-phase laminar flow numerical model for evaporation from a saltwater falling liquid film with a co-current humid air flow on the interior of a parallel plate vertical channel is presented. The elliptic governing equations in both phases are solved simultaneously in an implicit, fully coupled approach. The liquid-gas interface is tracked precisely on an automatically adjusted non-orthogonal structured mesh. The basis of the evaporation model is validated for pure water falling film evaporation. A parametric study of evaporation from a saltwater falling film is presented. The study varies the inlet salinity of the film, the inlet liquid Reynolds number, the wall heat flux, and the air relative humidity. The effects of these variations on quantities such as the evaporation rate, the axial velocity, the salinity in the film, and the temperature are presented. The results demonstrate the capablity of the new model to predict the details of falling film thermal desalination.

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Section: Introductionmentioning

confidence: 99%

A Two-Phase Sharp-Interface Numerical Model of Falling Film Thermal Desalination in a Vertical Channel

Tohidi,

Ormiston

2024

Preprint

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“…For film flow on the vertical walls, Huang et al [19] explored the film evaporation and sensible heat transfer inside the converging-diverging tubes, and found the rid height has great impact on the heat transfer performance. Eichinger et al [20] studied that the R290 film flow inside a vertical round tube, and showed the groove structure improves the wetting behavior and heat transfer. Wang et al [21] measured the film thickness on the vertical plate by the confocal chromatic technique, a film thickness correlation was proposed for the ionic liquids.Li et al [22] numerically studied the film flow outside the vertical tube, and found the ripple surface structure hinders the film spreading, which results in smaller velocity and greater film thickness compared with the smooth tube.…”

Section: Introductionmentioning

confidence: 99%

“…The working fluids studied in the existing literature are mainly concentrated in pure water [5][6][7][8]10,11,13,19,23,25], seawater [3], oil sewage [15,16], LiBr solution [17], freon refrigerant [9,20,22], ethylene glycol aqueous solution [14], potassium formate aqueous solution [24], ionic fluid [21,22]. For the cryogenic liquid, Pavlenko et al [26] measured the film flow of cryogenic liquid nitrogen on the surfaces with complex geometry, and found the microstructure has a significant influence on the film spreading progress.…”

Section: Introductionmentioning

confidence: 99%

Falling Film Flow and Heat Transfer of Cryogenic Liquid Oxygen on Different Structural Surfaces

et al. 2022

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The accurate prediction of the falling film characteristics of cryogenic liquids is necessary to ensure good evaporation performance, due to their special physical properties. In this study, the film flow and heat transfer characteristics on four different structures were investigated, and the performance of the cryogenic liquid oxygen was compared with other fluids with higher temperatures, which demonstrates the influence of structures and liquid mediums. The VOF model was used to capture the film surface in the simulation model. The results show that for the four structures, liquids with higher kinematic viscosity tend to have greater film thickness, and the sensible heat transfer coefficients are inversely related to the nominal thermal resistance of falling film flow. Both on the smooth plate and the corrugated plate, the film wettability depends on the kinematic viscosity, rather than the dynamic viscosity, and the effect of kinematic viscosity is greater than that of surface tension. Both the local heat transfer coefficient and its fluctuation amplitude decrease gradually along the flow direction on the triangular corrugated plate, and the vortices are easier to produce at the wall troughs when the film viscosity is higher. At the bottom of the horizontal tube, the increases in local film thickness of the liquid oxygen are less than those of the water and the seawater. More liquid tends to accumulate at the bottom of the round tube, while it easily detaches from the film surface of the elliptical tube. For the horizontal tubes, the local heat transfer coefficients decrease rapidly when θ = 0–5°, and increase sharply at θ = 175–180°.

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A two-phase sharp-interface numerical model of falling film thermal desalination in a vertical channel

Tohidi,

Ormiston

2024

Heat Mass Transfer

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Heat transfer and wetting behaviour of falling liquid films in inclined tubes with structured surfaces

Cited by 9 publications

References 41 publications

A Two-Phase Sharp-Interface Numerical Model of Falling Film Thermal Desalination in a Vertical Channel

A Two-Phase Sharp-Interface Numerical Model of Falling Film Thermal Desalination in a Vertical Channel

Falling Film Flow and Heat Transfer of Cryogenic Liquid Oxygen on Different Structural Surfaces

A two-phase sharp-interface numerical model of falling film thermal desalination in a vertical channel

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