The effect of dynamic wetting behavior on boiling heat transfer mechanisms during bubble growth and departure

Single vapour bubble growth and heat transfer mechanism during flow boiling in a rectangular horizontal mini-channel were experimentally investigated. The hydraulic diameter of the channel was 1454 μm, with an aspect ratio (Win/din) of 10. Degassed FC-72 was used as the working liquid. In this paper, bubble equivalent radius was found to increase linearly till a critical time, beyond which the growth turned into exponential. Bubble growth rate increases with increasing heat flux. Heat transfer mechanisms of the bubble growth at different heat fluxes and mass fluxes were discussed. In addition, the relation between thermal and flow conditions with bubble temporal geometry was explored.

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Microscale Vapor Bubble Interactions During Subcooled Nucleate Boiling on a Heated Wire

First International Conference on Integration and Commercialization of Micro and Nanosystems, Parts A and B ◽

10.1115/mnc2007-21308 ◽

2007 ◽

Cited By ~ 1

Author(s):

Lu Zhang ◽

David M. Christopher

Keyword(s):

Heat Transfer ◽

Vapor Bubble ◽

Boiling Heat Transfer ◽

Nucleate Boiling ◽

Bubble Behavior ◽

Transfer Rates ◽

Bubble Interactions ◽

Heated Wire ◽

Nucleate Boiling Heat Transfer ◽

Transfer Mechanisms

Bubbles have been observed moving along heated wires during subcooled nucleate boiling as they are driven by Marangoni convection around the bubbles. This paper presents more detailed observations of the vapor bubble interactions and moving bubble behavior during subcooled nucleate boiling on a heated microwire. The experimental results show that moving bubbles coalesce or rebound from other bubbles and that bubbles hop on the wire. These observations show how bubble interactions significantly affect nucleate boiling heat transfer rates and how Marangoni flow plays an important role in microscale nucleate boiling heat transfer mechanisms.

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Transient boiling heat transfer in a narrow channel (3rd report, Fluctuation phenomena in the channel due to bubble growth and collapse)

TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series B ◽

10.1299/kikaib.51.3539 ◽

1985 ◽

Vol 51 (471) ◽

pp. 3539-3547

Author(s):

Kunito OKUYAMA ◽

Shigebumi AOKI ◽

Yoshiyuki KOZAWA ◽

Akira INOUE

Keyword(s):

Heat Transfer ◽

Bubble Growth ◽

Boiling Heat Transfer ◽

Narrow Channel ◽

Fluctuation Phenomena ◽

Transient Boiling

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BOILING HEAT TRANSFER MECHANISMS IN A HORIZONTAL TUBE BUNDLE

Experimental Heat Transfer ◽

10.1080/08916159308946458 ◽

1993 ◽

Vol 6 (3) ◽

pp. 259-271 ◽

Cited By ~ 9

Author(s):

J.-T. Hsu ◽

C.-S. Lin ◽

M.-K. Jensen

Keyword(s):

Heat Transfer ◽

Boiling Heat Transfer ◽

Tube Bundle ◽

Horizontal Tube ◽

Transfer Mechanisms

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Identification of Pool Boiling Heat Transfer Mechanisms From a Wire Immersed in Saturated FC-72 Using a Single-Photo/LDA Method

Journal of Heat Transfer ◽

10.1115/1.2824024 ◽

1996 ◽

Vol 118 (1) ◽

pp. 117-123 ◽

Cited By ~ 29

Author(s):

C. N. Ammerman ◽

S. M. You ◽

Y. S. Hong

Keyword(s):

Heat Transfer ◽

Latent Heat ◽

Flow Rate ◽

Boiling Heat Transfer ◽

Laser Doppler Anemometry ◽

Volumetric Flow Rate ◽

Nucleate Boiling ◽

Nucleate Boiling Heat Transfer ◽

Unique Method ◽

Transfer Mechanisms

A unique method to determine the vapor volumetric flow rate above a heated wire utilizing a single photograph and laser-Doppler anemometry is developed and discussed. The volumetric flow rate is combined with additional analyses to determine the overall contributions to the total heat flux from four nucleate boiling heat transfer mechanisms (latent heat, natural convection, Marangoni flow, and microconvection). This method is applied to a 75-μm wire immersed in a saturated, highly wetting liquid (FC-72). Latent heat is identified as the dominant mechanism in the fully developed nucleate boiling regime.

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On the Heat Transfer Characteristics of a Single Bubble Growth and Departure During Pool Boiling

ASME 2016 14th International Conference on Nanochannels, Microchannels, and Minichannels ◽

10.1115/icnmm2016-8097 ◽

2016 ◽

Author(s):

Mostafa Mobli ◽

Chen Li

Keyword(s):

Heat Transfer ◽

Heat Flux ◽

Bubble Growth ◽

Pool Boiling ◽

Vof Method ◽

Physical Relationship ◽

Interface Diffusion ◽

Departure Time ◽

Parasitic Currents ◽

Bubble Growth And Departure

In the present study, bubble growth and departure characteristics during saturated pool boiling were investigated numerically, and a comprehensive model was proposed and developed to study the heat transfer during growth and departure of a bubble as well as bubble growth rate and departure time. Two-phase characteristics of the boiling phenomena can be captured by well-known Volume of Fluid (VOF) method. However, the VOF method is susceptible to parasitic currents because of approximate interface curvature estimations. Thus, sharp surface formula (SSF) method was employed to effectively eliminate the presence of the parasitic currents. VOF method is a volume capturing method and hence, may be subject to interface diffusion, due to the fact that interface is smeared through some number of computational cells. Interface compression scheme is applied to prevent the plausible interface diffusion of the VOF method. To avoid unrealistic temperature profiles at the solid-liquid surface, a conjugate heat transfer model was used to calculate the heat flux going into the liquid region from the heater through the solution of conduction equation in solids. Phase change at the interface was incorporated based on Hardt and Wondra’s model in which source terms are derived from a physical relationship for the evaporation mass flux. Furthermore, effects of micro region heat transfer on the departure time of the bubble was investigated. Micro region heat transfer was included in the model by solving a temporal evolution equation and incorporating the resulting heat flux in the tri-phase contact line. In this study, OpenFOAM package was used to investigate the characteristics of the bubble growth and departure as well as the wall heat flux. The model was benchmarked by comparing the simulation results to available experimental and numerical literatures, as well as analytical solutions.

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Single Bubble Boiling from an Artificial Cavity

Journal of Nanofluids ◽

10.1166/jon.2019.1719 ◽

2019 ◽

Vol 8 (8) ◽

pp. 1617-1631

Author(s):

Saeid Vafaei ◽

Hyungdae Kim

Keyword(s):

Heat Transfer ◽

Heat Flux ◽

Theoretical Model ◽

Bubble Growth ◽

Boiling Heat Transfer ◽

Pool Boiling ◽

Triple Line ◽

Single Bubble ◽

Cavity Size ◽

Cylindrical Cavities

Pool boiling heat transfer is an aggressive and complex phenomenon which needs to be simplified for a better understanding of the mechanism of bubble growth and departure and how boiling heat transfer can be enhanced. Single bubble boiling heat transfer is a simple version of boiling phenomenon which has been used to study the effective elements on pool boiling heat transfer. The purpose of the present review paper is to understand how to produce single bubble pool boiling on a heated substrate and investigate, how single bubble boiling phenomenon can be affected by geometry of cavities, cavity size, wettability, roughness, working fluid, subcooling, wall superheat, heat flux, gravity, etc. It was demonstrated that cylindrical cavities are capable to generate stable and continuous bubbling, small temperature fluctuation, low superheat with short waiting period. The cylindrical cavities can be manufactured very easily in small sizes which can be a good candidate to produce single bubble pool boiling. As heat flux increases, smaller cavities start becoming active. For a given depth, as cavity size increases, the bubble growth rate and departure volume increase. Surface wettability is another complex and important factor to modify the single bubble boiling heat transfer. Wettability depends mainly on force balance at the triple contact line which relies on solid–liquid–gas materials. In case of hydrophobic surfaces, the triple line has tendency to move toward liquid phase and expand the radius of triple line, so the initiation of nucleation is easier, the waiting time is shorter, the downward surface tension force becomes bigger since radius of triple line is larger, the bubble departure volume is higher and bubble growth period is longer. The effects of the rest of main parameters on single bubble boiling are discussed in this paper in details. In addition, a theoretical model is developed to predict the liquid-vapor interface for the single bubble boiling. The theoretical model is compared with single bubble boiling experimental data and good results observed.

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