Bubble frequencies and departure volumes at subatmospheric pressures

Cole, R.

doi:10.1002/aic.690130434

Cited by 254 publications

(78 citation statements)

References 12 publications

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“…In summary, they fall into three categories: 1) analytical models based on force analyses [19,38,39], 2) analytical models based on thermal analyses [40][41][42], and 3) semi-empirical models [43][44][45][46][47]. The correlation of Golorin et al [45] is the only one for which the analysis includes the effect of surface roughness explicitly, but it does not agree well enough with the present data to explore further here.…”

Section: Bubble Departure Diameter D Dmentioning

confidence: 99%

Nucleate boiling from smooth and rough surfaces – Part 2: Analysis of surface roughness effects on nucleate boiling

McHale

Garimella

2013

Experimental Thermal and Fluid Science

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The effect of surface roughness on nucleate boiling heat transfer is not clearly understood.This study is devised to conduct detailed heat transfer and bubble measurements during boiling on a heater surface with controlled roughness. This second of two companion papers presents an analysis of heat transfer and bubble ebullition in nucleate boiling with new measures of surface roughness: area ratio, surface mean normal angle, and maximum idealized surface on the boiling curves and bubble behaviors suggests that the relative "roughness" of a surface should be quantified in a manner different from existing approaches to date in the literature.Several recent studies have reported attempts to develop surface characterization methods that relate more directly to boiling physics. Qi et al.[2] applied a digital "filtering" operation on 2-D surface scan data to examine potential nucleation sites in terms of cavity mouth radius and cone angle. They did not elaborate on the details of the algorithm; predictions of nucleation site density based on their analysis produced mixed results. ANALYSIS OF SURFACE ROUGHNESSIn the companion paper to this work [1], six borosilicate glass substrates were roughened by abrading with diamond compound to impart microscopic-scale roughness features, then annealed to control roughness characteristics at the nanoscale. One substrate (test piece 1) was not abraded or annealed. All seven substrates were coated conformally with an electrically conductive ITO layer, from which a 400 µm wide × 25 mm long heater/sensor device was patterned on each substrate. Each test piece was fixed at the base of a thermally controlled chamber that allowed saturated nucleate boiling heat transfer to be measured while recording 5 high-speed videographic visualizations from beneath the test surface and from the side simultaneously.Test pieces 4, 6, and 7 were abraded with the same diamond compound such that R a values (and therefore microscopic-scale roughness features) would be similar. These three surfaces, however, were exposed to different annealing conditions of temperature and soak period as shown in Table 1 [1] such that the roughness characteristics at the nanoscale are very different.Boiling performance for the three surfaces differed as described in and is valid for contact angles up to roughly 150°. The Fritz departure diameter meets the criteria above, including fluid properties and wetting characteristic. Filtered vertical roughness parametersAfter the filtering operation, new values of R a for the test substrates were calculated by the method described in [1], and are listed in Table 2. For each surface, there was little to no difference between the values calculated for different interrogation window sizes; the lowest values are reported here. After the filtering operation, the average roughness values of surfaces 6 and 7 (abraded with 100-µm particles and annealed more aggressively) fell below that of surface 3 (abraded with 30-µm particles). Indeed, surface 7 appears to be similar in roug...

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Section: Bubble Departure Diameter D Dmentioning

confidence: 99%

Nucleate boiling from smooth and rough surfaces – Part 2: Analysis of surface roughness effects on nucleate boiling

McHale

Garimella

2013

Experimental Thermal and Fluid Science

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“…The average departure diameters for each case, shown in Figure 12, were compared to correlations for departure diameter given by Fritz (1935), Zuber (1959), Ruckenstein, Cole and Shulman (1966), Hatton and Hall (1966), Cole (1967), Cole and Rohsenow (1969), Kutateladze and Gogonin (1980), Borishanskiy, et al (1981), Jensen and Memmel (1986), and Lee, et al (2003). The experimentally measured departure diameters increased with heat flux and wall superheat for each surface.…”

Section: Departure Diametermentioning

confidence: 99%

Bubble nucleation characteristics in pool boiling of a wetting liquid on smooth and rough surfaces

McHale

Garimella

2010

International Journal of Multiphase Flow

155

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“…Cole and Shulman measured and correlated the effect of pressure on bubble departure diameters from a thin, 12.7 x 101.6 mm horizontal zirconium ribbon [2]. The data of Raben et.…”

Section: Introductionmentioning

confidence: 99%

Pool boiling enhancement techniques for water at low pressure

McGillis

Carey

Fitch³

et al.

1991 Proceedings, Seventh IEEE Semiconductor Thermal Measurement and Management Symposium

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The Western Research Laboratory (WRL) is a computer systems research group that was founded by Digital Equipment Corporation in 1982. Our focus is computer science research relevant to the design and application of high performance scientific computers. We test our ideas by designing, building, and using real systems. The systems we build are research prototypes; they are not intended to become products.There is a second research laboratory located in Palo Alto, the Systems Research Center (SRC). Other Digital research groups are located in Paris (PRL) and in Cambridge, Massachusetts (CRL).Our research is directed towards mainstream high-performance computer systems. Our prototypes are intended to foreshadow the future computing environments used by many Digital customers. The long-term goal of WRL is to aid and accelerate the development of high-performance uni-and multi-processors. The research projects within WRL will address various aspects of high-performance computing.We believe that significant advances in computer systems do not come from any single technological advance. Technologies, both hardware and software, do not all advance at the same pace. System design is the art of composing systems which use each level of technology in an appropriate balance. A major advance in overall system performance will require reexamination of all aspects of the system.We do work in the design, fabrication and packaging of hardware; language processing and scaling issues in system software design; and the exploration of new applications areas that are opening up with the advent of higher performance systems. Researchers at WRL cooperate closely and move freely among the various levels of system design. This allows us to explore a wide range of tradeoffs to meet system goals.We publish the results of our work in a variety of journals, conferences, research reports, and technical notes. This document is a research report. Research reports are normally accounts of completed research and may include material from earlier technical notes. We use technical notes for rapid distribution of technical material; usually this represents research in progress. UUCP: decwrl!wrl-techreportsTo obtain more details on ordering by electronic mail, send a message to one of these addresses with the word ''help'' in the Subject line; you will receive detailed instructions. Pool Boiling Enhancement Techniques for AbstractSaturated pool boiling of water at low, sub-atmospheric pressures from a heated, 12.7 x 12.7 mm horizontal surface was examined. Rectangular fins, fluidized particulate beds, and surface finishes were used to enhance heat transfer. Water at low pressure significantly decreases the boiling performance below that of water at atmospheric pressure. However, surface temperatures are reduced to values acceptable for cooling electronic components. All rectangular fin geometries were found to enhance heat transfer, although certain geometries were more effective. The finned surfaces extended the base area critical heat flux (CHF) ...

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Bubble frequencies and departure volumes at subatmospheric pressures

Cited by 254 publications

References 12 publications

Nucleate boiling from smooth and rough surfaces – Part 2: Analysis of surface roughness effects on nucleate boiling

Nucleate boiling from smooth and rough surfaces – Part 2: Analysis of surface roughness effects on nucleate boiling

Bubble nucleation characteristics in pool boiling of a wetting liquid on smooth and rough surfaces

Pool boiling enhancement techniques for water at low pressure

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