Modeling of the bubble dynamics and heat flux variations during lateral coalescence of bubbles in nucleate pool boiling

2021 ◽  
pp. 103701
Author(s):  
Junjie Yuan ◽  
Xin Ye ◽  
Yanguang Shan
Keyword(s):  
Heat Flux ◽  
Bubble Dynamics ◽  
Pool Boiling ◽  
Nucleate Pool Boiling

The Mechanism of and Stability Criterion for Nucleate Pool Boiling of Sodium

1969 ◽  
Vol 91 (3) ◽  
pp. 315-328 ◽  
Author(s):  
I. Shai ◽  
W. M. Rohsenow
Keyword(s):  
Heat Flux ◽  
Liquid Metals ◽  
Bubble Formation ◽  
Pool Boiling ◽  
Heat Fluxes ◽  
Nucleate Pool Boiling ◽  
Thermal Layer ◽  
Minimum Heat ◽  
Bubble Growth And Departure ◽  
Recorded Temperature

Experimental data for sodium boiling on horizontal surfaces containing artificial cavities at heat fluxes of 20,000 to 300,000 Btu/ft2 hr and pressures between 40 to 106 mm Hg were obtained. Observations are made for stable boiling, unstable boiling and “bumping.” Some recorded temperature variations in the solid close to the nucleating cavity are presented. It is suggested that for liquid metals the time for bubble growth and departure is a very small fraction of the total bubble cycle, hence the delay time during which a thermal layer grows is the most significant part of the process. On this basis the transient conduction heat transfer is solved for a periodic process, and the period time is found to be a function of the degree of superheat, the heat flux and the liquid thermal properties. A simplified model for stability of nucleate pool boiling of liquid metals is postulated from which the minimum heat flux for stable boiling can be found as a function of liquid-solid properties, liquid pressure, the degree of superheat, and the cavity radius and depth. At relatively low heat fluxes, convection currents have significant effects on the period time of bubble formation. An empirical correlation is proposed, which takes into account the convection effects, to match the experimental results.

Combined Pressure and Subcooling Effects on Pool Boiling From a PPGA Chip Package

1997 ◽  
Vol 119 (2) ◽  
pp. 95-105 ◽  
Author(s):  
A. A. Watwe ◽  
A. Bar-Cohen ◽  
A. McNeil
Keyword(s):  
Heat Flux ◽  
Experimental Investigation ◽  
Critical Heat Flux ◽  
Pool Boiling ◽  
Combined Effects ◽  
Minimal Effect ◽  
Nucleate Pool Boiling ◽  
Lower Wall ◽  
Saturated Liquid

This study presents a detailed experimental investigation of the combined effects of pressure and subcooling on nucleate pool boiling and critical heat flux (CHF) for degassed fluorocarbon FC-72 boiling on a plastic pin-grid-array (PPGA) chip package. In these experiments pressure was varied between 101.3 and 303.9 kPa and the subcooling ranged from 0 to 65°C. As expected, lower wall superheats resulted from increases in pressure, while subcooling had a minimal effect on fully developed pool boiling. However, the superheat reductions and CHF enhancements were found to be smaller than those predicted by existing models. The CHF for saturated liquid conditions increased by nearly 17 percent for an increase in pressure from 101.3 to 202.7 kPa. In experiments with both FC-72 and FC-87 further increases in pressure did not produce any significant increase in CHF. At a pressure of 101.3 kPa a subcooling of 30°C increased CHF on horizontal upward-facing chips by approximately 50 percent, as compared to 70 percent on vertically oriented packages. The enhancement in CHF due to subcooling decreased rapidly with increasing pressure, and the data showed that the influence of pressure and subcooling on CHF is not additive. A correlation to predict pool boiling CHF under the combined effects of pressure and subcooling is proposed.

IR thermographic investigation of nucleate pool boiling at high heat flux

2016 ◽  
Vol 61 ◽  
pp. 127-139 ◽  
Author(s):  
Jure Petkovsek ◽  
Yi Heng ◽  
Matevz Zupancic ◽  
Henrik Gjerkes ◽  
Franc Cimerman ◽  
...  
Keyword(s):  
Heat Flux ◽  
Pool Boiling ◽  
High Heat ◽  
High Heat Flux ◽  
Nucleate Pool Boiling ◽  
Thermographic Investigation

Influence of heat flux and pressure on heat transfer associated with fully developed nucleate pool boiling

1977 ◽  
Vol 33 (5) ◽  
pp. 1304-1306
Author(s):  
V. K. Andreev ◽  
V. I. Deev ◽  
A. K. Kondratenko ◽  
V. I. Petrovichev ◽  
V. E. Keilin ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Pool Boiling ◽  
Nucleate Pool Boiling

Investigation of Bubble Departure Radius in Subcooled Pool Boiling Under Microgravity Condition

2018 ◽  
Author(s):  
Xueli Wang ◽  
Zan Wu ◽  
Jinjia Wei ◽  
Bengt Sunden
Keyword(s):  
Heat Flux ◽  
Contact Angle ◽  
High Speed ◽  
Bubble Dynamics ◽  
Pool Boiling ◽  
Microgravity Condition ◽  
Force Balance ◽  
Balance Model ◽  
Silicon Chips ◽  
Static Contact

The bubble departure radius is a very important parameter for bubble dynamics during boiling heat transfer. In this study, experiments of highly subcooled nucleate pool boiling of FC-72 were conducted on two different sized silicon chips (chip S 2 × 2 and chip S 1 × 1) in short-term microgravity and normal gravity conditions by utilizing the drop tower in Beijing. During the experimental study, bubble dynamics were captured by a high-speed digital camera. From the images at the bubble departure moment, the bubble departure radius was obtained. Although the traditional force balance model is modified through the addition of a Marangoni force, it still cannot precisely predict the bubble departure radius in the microgravity condition, especially in the low heat flux regime. By using the advancing contact angle measured from the bubble departure moment instead of the static contact angle, and considering the bubble asymmetry due to the small bubble coalescence and the surrounding liquid motion, a revised force balance model is proposed. It can predict the experimental bubble departure radius within a deviation of ±3.8% for both silicon chips in the whole heat flux range.

Electrohydrodynamic effects on bubble dynamics during nucleate pool boiling under the leaky dielectric assumption

2022 ◽  
Vol 34 (1) ◽  
pp. 013606
Author(s):  
Jing-Da Yao ◽  
Kang Luo ◽  
Jian Wu ◽  
Hong-Liang Yi
Keyword(s):  
Bubble Dynamics ◽  
Pool Boiling ◽  
Nucleate Pool Boiling ◽  
Leaky Dielectric
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