Comparison of different analytical models for heat and mass transfer characteristics of an evaporating meniscus in a micro-channel

Kou, Zhihai; Lv, Hongtao; Zeng, Wen; Bai, Ming; Lv, Jizu

doi:10.1016/j.icheatmasstransfer.2015.02.005

Cited by 29 publications

(10 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…h lv is the latent heat; k l is the liquid thermal conductivity; M is the molar mass; V l is the molar volume of liquid; R u is the universal gas constant; and c is the accommodation coefficient, which is taken as unity [15,21,23,43,44].…”

Section: Physical Model and Governing Equationsmentioning

confidence: 99%

“…Thermal performance of a two-phase passive heat spreader is basically dictated by its capillary pumping ability together with the phase change efficiency of the evaporator and condenser sections. Despite the abundance of studies focusing on the modeling of evaporation in grooved heat pipes, [12,13,14,15,16,17,18,19,20,21,22,23,24,25], studies on the condensation modeling remain restricted [14,15,16,26,27,28,29]. In a grooved heat pipe, condensation modeling targets to capture the physics on the fin top and near the fin-groove corner since the condensation intensifies on the fin top because of the small thickness of liquid (micro-scale) compared to the one inside the groove (mili-scale).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

On the effect of structural forces on a condensing film profile near a fin-groove corner

Akdag,

Akkus,

Dursunkaya

2020

Preprint

View full text Add to dashboard Cite

Estimation of condenser performance of two-phase passive heat spreaders with grooved wick structures is crucial in the prediction of the overall performance of the heat spreader.Whilst the evaporation problem in micro-grooves has been widely studied, studies focusing on the condensation on fin-groove systems have been scarce. Condensation on fin-groove systems is actually a multi-scale problem. Thickness of the film near the fin-groove corner can decrease to nanoscale dimensions, which requires the inclusion of nanoscale effects into the modeling. While a few previous studies investigated the effect of dispersion forces, the effect of structural forces has never been considered in the thin film condensation modeling on fin-groove systems. The present study utilizes a disjoining pressure model which considers both dispersion and structural forces. The results reveal that structural forces are able to dominate dispersion forces in certain configurations. Consequently, by intensifying the disjoining pressure, structural forces lead to a sudden change of the film profile (slope break) for subcooling values which are relevant to engineering applications.

show abstract

Section: Physical Model and Governing Equationsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

On the effect of structural forces on a condensing film profile near a fin-groove corner

Akdag,

Akkus,

Dursunkaya

2020

Preprint

View full text Add to dashboard Cite

show abstract

“…If the length of the surface in the direction of the flow is much longer than the film thickness or Reynolds number is small, lubrication assumption can be utilized for the liquid flow on the planar surface. For the flow of condensate on the fin top [11,12,13,14,15,35] or the flow of liquid on a heated planar substrate towards the contact line [11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34], lubrication assumption has been widely utilized. For a cylindrical surface, on the other hand, Reynolds number is defined as Re = u ϕ δ ν, where u ϕ is the mean angular velocity in ϕ-direction, and the extent of the flow is expressed as the function of the radius of the cylindrical surface (L f low = R o ϕ).…”

Section: Lubrication Assumptionmentioning

confidence: 99%

“…Modeling the physics inside the heat pipe is complicated, since it involves different scale problems: macro-scale in axial liquid and vapor flow and micro-scale in thin film evaporation and condensation near the groove edges. While the modeling of evaporation is widely studied [11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34], studies on the condensation modeling remain restricted [11,12,13,14,15,35,36]. In the condenser section of a grooved heat pipe, the thickness of liquid on the fin tops is much smaller than the one inside the groove, which makes the resistance to heat transfer much lower on the fin tops.…”

Section: Introductionmentioning

confidence: 99%

The effect of disjoining pressure on the shape of condensing films in a fin-groove corner

Akdag,

Akkus,

Dursunkaya

2018

Preprint

View full text Add to dashboard Cite

Thin film condensation is commonly present in numerous natural and artificial processes. Phase-change driven passive heat spreaders such as heat pipes, which are widely used in electronics cooling, employ a continuous condensation process at the condenser region. When the wick structure of a heat pipe is composed of grooves, the top surfaces of the walls (fins) located between consecutive grooves function as the major source of condensation and the condensate flows along the fin top into the grooves. Modeling of this condensation problem is vital for the proper estimation of condensation heat transfer, which constitutes the basis for the overall performance of an heat pipe together with the evaporation process. In the current study, a solution methodology is developed to model the condensation and associated liquid flow in a fin-groove system. Conservation of mass and momentum equations, augmented Young-Laplace equation and Kucherov-Rikenglaz equation are solved simultaneously to calculate the film thickness profile. The model proposed enables the investigation of the effect of disjoining pressure on the film profile by keeping the fin-groove corner, where the film becomes thinnest, inside the solution domain. The results show that dispersion forces become effective for near isothermal systems with sharp fin-groove corners and the film profile experiences an abrupt change, a slope break, in the close proximity of the corner. The current study is the first computational confirmation of this behavior in the literature.

show abstract

“…As the heat flux imposed on the thin film region increases, the evaporation and heat transfer rates through the evaporating thin film also increase [28]. More information on the mechanisms of heat transfer in capillary assisted grooved tubes can be found elsewhere [22,27,[29][30][31].…”

Section: Capillary-assisted Evaporationmentioning

confidence: 99%

Performance of finned tubes used in low-pressure capillary-assisted evaporator of adsorption cooling system

Thimmaiah

Sharafian

Huttema

et al. 2016

Applied Thermal Engineering

View full text Add to dashboard Cite

Comparison of different analytical models for heat and mass transfer characteristics of an evaporating meniscus in a micro-channel

Cited by 29 publications

References 19 publications

On the effect of structural forces on a condensing film profile near a fin-groove corner

On the effect of structural forces on a condensing film profile near a fin-groove corner

The effect of disjoining pressure on the shape of condensing films in a fin-groove corner

Performance of finned tubes used in low-pressure capillary-assisted evaporator of adsorption cooling system

Contact Info

Product

Resources

About