Geometrical effects on heat transfer mechanisms during pool boiling in Dual Tapered Microgap with HFE7000

2022 ◽  
Vol 183 ◽  
pp. 122165
Author(s):  
Aranya Chauhan ◽  
Satish G. Kandlikar
Keyword(s):  
Heat Transfer ◽  
Pool Boiling ◽  
Geometrical Effects ◽  
Transfer Mechanisms

Saturated Pool Boiling Mechanisms During Single Bubble Heat Transfer: Comparison at Two Wall Superheats

2000 ◽  
Author(s):  
Jungho Kim ◽  
Fatih Demiray ◽  
Nagaraja Yaddanapudi
Keyword(s):  
Heat Transfer ◽  
Constant Temperature ◽  
Pool Boiling ◽  
Minor Role ◽  
Dominant Mechanism ◽  
Different Temperatures ◽  
Transient Conduction ◽  
Microlayer Evaporation ◽  
A Minor ◽  
Transfer Mechanisms

Abstract A study of single bubbles growing on a microscale heater array kept at nominally constant temperature was performed. The behavior of bubbles nucleating at a single site at two different temperatures (22.5 K and 27.5 K superheat) is compared for saturated pool boiling of FC-72 at 1 atm. It is concluded that energy is transferred from the surface through similar heat transfer mechanisms at both superheats. Microlayer evaporation was observed to play a minor role in the overall heat transfer, with microconvection/transient conduction being the dominant mechanism. Evaluation of various heat transfer models are made.

Nucleate Pool Boiling: The Dominant Bubble Heat Transfer Mechanisms

2009 ◽  
Author(s):  
Jungho Kim
Keyword(s):  
Heat Transfer ◽  
Contact Line ◽  
Pool Boiling ◽  
Nucleate Pool Boiling ◽  
Transfer Energy ◽  
Numerical Work ◽  
Transient Conduction ◽  
Microlayer Evaporation ◽  
Transfer Mechanisms ◽  
Fitting Parameters

Enhanced convection, transient conduction, microlayer evaporation, and contact line heat transfer have all been proposed as mechanisms by which bubbles transfer energy during boiling. Models based on these mechanisms contain fitting parameters that are used to fit them to the data, resulting a proliferation of “validated” models. A review of the recent experimental, analytical, and numerical work into single bubble heat transfer is presented to determine the contribution of each of the above mechanisms to the overall heat transfer. Transient conduction and microconvection are found to be the dominant heat transfer mechanisms.

scholarly journals Time and Space Resolved Heat Transfer Measurements Under Nucleate Bubbles With Constant Heat Flux Boundary Conditions

2003 ◽  
Author(s):  
Jerry G. Myers ◽  
Sam W. Hussey ◽  
Glenda F. Yee ◽  
Jungho Kim
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Characteristic Length ◽  
Pool Boiling ◽  
Constant Heat Flux ◽  
Time And Space ◽  
Constant Heat ◽  
Transfer Data ◽  
Flux Boundary Conditions ◽  
Transfer Mechanisms

Investigations into single bubble pool boiling phenomena are often complicated by the difficulties in obtaining time and space resolved information in the bubble region. This usually occurs because the heaters and diagnostics used to measure heat transfer data are often on the order of, or larger than, the bubble characteristic length or region of influence. This has contributed to the development of many different and sometimes contradictory models of pool boiling phenomena and dominant heat transfer mechanisms.

Gas-Saturated Pool Boiling Heat Transfer From Smooth and Microporous Surfaces in FC-72

1996 ◽  
Vol 118 (3) ◽  
pp. 662-667 ◽  
Author(s):  
J. P. O’Connor ◽  
S. M. You ◽  
J. Y. Chang
Keyword(s):  
Heat Transfer ◽  
Boiling Heat Transfer ◽  
Smooth Surface ◽  
Pool Boiling ◽  
Nucleate Boiling ◽  
Pure Liquid ◽  
Dissolved Gas ◽  
Pool Boiling Heat Transfer ◽  
Boiling Process ◽  
Transfer Mechanisms

The effects of surface treatments and “gassy-subcooling” on pool boiling heat transfer are quantified by testing both smooth and treated surfaces at gassy-subcooling levels from O°C to 40°C (1 atm) and 40°C to 85°C (3 atm). Incipient and nucleate boiling wall superheats decrease over this range of gassy-subcooling. At gassy-subcooling levels greater than 20°C, the boiling curves for the smooth surface indicate two distinct regions governed by different heat transfer mechanisms, one in which the boiling process is influenced by the presence of dissolved gas, the other by boiling of the pure liquid. The critical heat flux (CHF) for each surface continually increases with increased levels of gassy-subcooling and the CHF sensitivity to gassy-subcooling is higher for the treated surface. The CHF increase due to combined surface treatment and gassy-subcooling (85°C) is ~400 percent (78 W/cm2).

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