Bubble dynamics and pressure oscillation in highly subcooled water jet array impingement boiling under periodical heat flux

An experimental investigation was carried out for predicting the critical heat flux (CHF) of steady boiling for a round subcooled water jet impingement on the flat stagnation zone. The experimental data were measured in a steady nucleate boiling state. Three main influencing parameters, i.e., subcooling, impact velocity and jet nozzle size were widely changed and their effects on the critical heat flux were systemically studied. An empirical correlation was obtained using the experimental data over a wide experimental range for predicting the critical heat flux of steady boiling for a round subcooled water jet impingement on the flat stagnation zone.

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Predicting Critical Heat Flux With Multiphase CFD: 4 Years in the Making

Volume 1C, Symposia: Gas-Liquid Two-Phase Flows; Gas and Liquid-Solid Two-Phase Flows; Numerical Methods for Multiphase Flow; Turbulent Flows: Issues and Perspectives; Flow Applications in Aerospace; Fluid Power; Bio-Inspired Fluid Mechanics; Flow Manipulation and Active Control; Fundamental Issues and Perspectives in Fluid Mechanics; Transport Phenomena in Energy Conversion From Clean and Sustainable Resources; Transport Phenomena in Materials Processing and Manufacturing Processes ◽

10.1115/fedsm2017-69242 ◽

2017 ◽

Cited By ~ 2

Author(s):

Emilio Baglietto ◽

Etienne Demarly ◽

Ravikishore Kommajosyula

Keyword(s):

Heat Transfer ◽

Heat Flux ◽

Critical Heat Flux ◽

Bubble Dynamics ◽

Flow Boiling ◽

Heated Surface ◽

Force Balance ◽

Modeling Framework ◽

Lift Off ◽

Limiting Condition

Advancement in the experimental techniques have brought new insights into the microscale boiling phenomena, and provide the base for a new physical interpretation of flow boiling heat transfer. A new modeling framework in Computational Fluid Dynamics has been assembled at MIT, and aims at introducing all necessary mechanisms, and explicitly tracks: (1) the size and dynamics of the bubbles on the surface; (2) the amount of microlayer and dry area under each bubble; (3) the amount of surface area influenced by sliding bubbles; (4) the quenching of the boiling surface following a bubble departure and (5) the statistical bubble interaction on the surface. The preliminary assessment of the new framework is used to further extend the portability of the model through an improved formulation of the force balance models for bubble departure and lift-off. Starting from this improved representation at the wall, the work concentrates on the bubble dynamics and dry spot quantification on the heated surface, which governs the Critical Heat Flux (CHF) limit. A new proposition is brought forward, where Critical Heat Flux is a natural limiting condition for the heat flux partitioning on the boiling surface. The first principle based CHF is qualitatively demonstrated, and has the potential to deliver a radically new simulation technique to support the design of advanced heat transfer systems.

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Evaporation and Nucleate Boiling of an Individual Droplet on Surfaces

Heat Transfer: Volume 4 ◽

10.1115/ht2005-72316 ◽

2005 ◽

Author(s):

X. D. Wang ◽

G. Lu ◽

X. F. Peng ◽

B. X. Wang

Keyword(s):

Heat Flux ◽

High Speed ◽

Bubble Dynamics ◽

Imaging System ◽

Dynamical Behavior ◽

Saturation Temperature ◽

Nucleate Boiling ◽

Dynamical Process ◽

Boiling Regime ◽

Film Evaporation

A visual study was conducted to investigate the evaporation and nucleate boiling of a water droplet on heated copper, aluminum, or stainless surfaces with temperature ranging from 50°C to 112°C. Using a high-speed video imaging system, the dynamical process of the evaporation of a droplet was recoded to measure the transient variation of its diameter, height, and contact angle. When the contact temperature was lower than the saturation temperature, the evaporation was in film evaporation regime, and the evaporation could be divided into two stages. When the surface temperature was higher than the saturation temperature, the nucleate boiling was observed. The dynamical behavior of nucleation, bubble dynamics droplet were detail observed and discussed. The linear relationships of the average heat flux vs. temperature of the heated surfaces were found to hold for both the film evaporation regime and nucleate boiling regime. The different slopes indicated their heat transfer mechanism was distinct, the heat flux decreased in the nucleate boiling regime more rapidly than in the film evaporation due to the strong interaction between the bubbles.

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A Procedure to Predict Subcooled-Water-Flow-Boiling CHF in Uniformly Heated Tubes for High-Heat-Flux Applications

Nuclear Technology ◽

10.13182/nt00-a3096 ◽

2000 ◽

Vol 130 (3) ◽

pp. 310-328 ◽

Cited By ~ 1

Author(s):

Young Min Kwon ◽

Soon Heung Chang

Keyword(s):

Heat Flux ◽

Water Flow ◽

Flow Boiling ◽

High Heat ◽

High Heat Flux ◽

Subcooled Water

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Critical Heat Flux in Subcooled Water Flow of One-Side-Heated Screw Tubes

Fusion Technology ◽

10.13182/fst99-a82 ◽

1999 ◽

Vol 35 (3) ◽

pp. 289-296 ◽

Cited By ~ 15

Author(s):

Jean Boscary ◽

Masanori Araki ◽

Satoshi Suzuki ◽

Koichiro Ezato ◽

Masato Akiba

Keyword(s):

Heat Flux ◽

Critical Heat Flux ◽

Water Flow ◽

Subcooled Water

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A Photographic Study on the Effects of Hydrophobic-Spot Size and Subcooling on Local Film Boiling

ASME 2013 11th International Conference on Nanochannels, Microchannels, and Minichannels ◽

10.1115/icnmm2013-73069 ◽

2013 ◽

Author(s):

Bambang Joko Suroto ◽

Masahiro Tashiro ◽

Sana Hirabayashi ◽

Sumitomo Hidaka ◽

Masamichi Kohno ◽

...

Keyword(s):

Heat Flux ◽

High Speed ◽

Bubble Dynamics ◽

Pure Water ◽

Nucleate Boiling ◽

Spot Size ◽

Copper Surface ◽

Film Boiling ◽

Working Fluid ◽

Boiling Regime

The effects of hydrophobic circle spot size and subcooling on local film boiling phenomenon from the copper surface with single PTFE (Polytetrafluoroethylene) hydrophobic circle spot at low heat flux has been investigated. The experiments were performed using pure water as the working fluid and subcooling ranging from 0 and 10K. The heat transfer surfaces are used polished copper block with single PTFE hydrophobic circle spot of diameters 2, 4 and 6 mm, respectively. A high-speed camera was used to capture bubble dynamics and disclosed the sequence of the process leading to local film boiling. The result shows that local films boiling occurs on the PTFE circle spot at low heat flux and was triggered by the merging of neighboring bubbles. The study also showed that transition time required for change from nucleate boiling regime to local film boiling regime depends on the diameter of the hydrophobic circle spot and the subcooling. A stable local film boiling occurs at the smallest diameter of hydrophobic spot. Subcooling cause the local film boiling occur at negative superheat and oscillation of bubble dome.

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Conductive and viscous sub-layers on forced convection and mechanism of critical heat flux during flow boiling of subcooled water in a circular tube at high liquid Reynolds number

Heat and Mass Transfer ◽

10.1007/s00231-018-2458-4 ◽

2018 ◽

Vol 55 (1) ◽

pp. 175-195 ◽

Cited By ~ 2

Author(s):

K. Hata ◽

Q. S. Liu ◽

S. Masuzaki

Keyword(s):

Heat Flux ◽

Reynolds Number ◽

Forced Convection ◽

Critical Heat Flux ◽

Circular Tube ◽

Flow Boiling ◽

Subcooled Water

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An Experimental Investigation of the Film Boiling of Subcooled Water by Gradient Heat Flux Measurement

Technical Physics Letters ◽

10.1134/s1063785019030350 ◽

2019 ◽

Vol 45 (3) ◽

pp. 253-255 ◽

Cited By ~ 6

Author(s):

S. Z. Sapozhnikov ◽

V. Yu. Mityakov ◽

A. V. Mityakov ◽

V. V. Subbotina

Keyword(s):

Heat Flux ◽

Experimental Investigation ◽

Flux Measurement ◽

Film Boiling ◽

Heat Flux Measurement ◽

Subcooled Water

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Critical Heat Flux in Subcooled Water Flow in a Saw-Toothed Finned Duct Under One-Sided Heating Conditions

Fusion Technology ◽

10.13182/fst01-a11963351 ◽

2001 ◽

Vol 39 (2P2) ◽

pp. 885-889 ◽

Cited By ~ 1

Author(s):

Koichiro Ezato ◽

Satoshi Suzuki ◽

Kazuyoshi Sato ◽

Masaki Taniguchi ◽

Masato Akiba

Keyword(s):

Heat Flux ◽

Critical Heat Flux ◽

Water Flow ◽

Subcooled Water

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Steady-State Subcooled Nucleate Boiling on a Downward-Facing Hemispherical Surface

Journal of Heat Transfer ◽

10.1115/1.2824258 ◽

1998 ◽

Vol 120 (2) ◽

pp. 365-370 ◽

Cited By ~ 13

Author(s):

K. H. Haddad ◽

F. B. Cheung

Keyword(s):

Heat Flux ◽

Steady State ◽

Heat Transport ◽

Bubble Dynamics ◽

Flow Direction ◽

Heating Surface ◽

Nucleate Boiling ◽

High Heat ◽

Bubble Nucleation ◽

High Heat Flux

Steady-state nucleate boiling heat transfer experiments in saturated and subcooled water were conducted. The heating surface was a 0.305 m hemispherical aluminum vessel heated from the inside with water boiling on the outside. It was found that subcooling had very little effect on the nucleate boiling curve in the high heat flux regime where latent heat transport dominated. On the other hand, a relatively large effect of subcooling was observed in the low-heat-flux regime where sensible heat transport was important. Photographic records of the boiling phenomenon and the bubble dynamics indicated that in the high-heat-flux regime, boiling in the bottom center region of the vessel was cyclic in nature with a liquid heating phase, a bubble nucleation and growth phase, a bubble coalescence phase, and a large vapor mass ejection phase. At the same heat flux level, the size of the vapor masses was found to decrease from the bottom center toward the upper edge of the vessel, which was consistent with the increase observed in the critical heat flux in the flow direction along the curved heating surface.

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