Simultaneous visualization of dry spots and bubbles for pool boiling of R-113 on a horizontal heater

Chung, Hongsuk; No, Hee Cheon

doi:10.1016/s0017-9310(02)00524-0

Cited by 48 publications

(19 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…All dry areas are eventually rewetted at heat fluxes below CHF. In their boiling experiments with ethanol and refrigerants, Nishio and Tanaka [2004] and Chung and No [2003] also observed large dry areas similar to ours.…”

Section: Wetted Area Fraction In Nucleate Boilingsupporting

confidence: 86%

Measurement of wetted area fraction in subcooled pool boiling of water using infrared thermography

Kim

Park

Buongiorno

2013

Nuclear Engineering and Design

View full text Add to dashboard Cite

The wetted area fraction in subcooled pool boiling of water at atmospheric pressure is measured using the DEPIcT (DEtection of Phase by Infrared Thermography) technique. DEPIcT exploits the contrast in infrared (IR) light emissions between wet and dry areas on the surface of an IRtransparent heater to visualize the instantaneous distribution of the liquid and gas phases in contact with the heater surface. In this paper time-averaged wetted area fraction data in nucleate boiling are reported as functions of heat flux (from 30% up to 100% of the Critical Heat Flux) and subcooling (T sub = 0, 5, 10, 30 and 50C). The results show that the wetted area fraction monotonically decreases with increasing heat flux and increases with increasing subcooling: both trends are expected. The range of time-averaged wetted area fractions is from 90%, at low heat flux and high subcooling, to 50% at high heat flux (right before CHF) and low subcooling. It is also shown that the dry areas are periodically rewetted by liquid sloshing on the surface at any subcooling and heat flux; however, the dry areas expand irreversibly at CHF.

show abstract

Section: Wetted Area Fraction In Nucleate Boilingsupporting

confidence: 86%

Measurement of wetted area fraction in subcooled pool boiling of water using infrared thermography

Kim

Park

Buongiorno

2013

Nuclear Engineering and Design

View full text Add to dashboard Cite

show abstract

“…by Nishio et al [3] and Chung and No [4], showed near to CHF the existence of a fluctuating network of liquid contact zones that maintained cooling. Theofanous et al [5,6] showed that individual bubbles could maintain their identity at very high heat fluxes; CHF occurred when the transient temperature rise at the dry patches under bubbles was so high that rewetting was prevented.…”

mentioning

confidence: 93%

A study of nucleate boiling and critical heat flux with EHD enhancement

et al. 2007

View full text Add to dashboard Cite

Abstract. The paper describes results from an experimental and theoretical study of the effect of an electric field on nucleate boiling and the critical heat flux (CHF) in pool boiling of R123 at atmospheric pressure on a horizontal wall with a smooth surface.Two designs of electrode (parallel rods and wire mesh) were used.The experimental data exhibit some differences from the data obtained by other researchers in similar experiments on a wall with a different surface finish and with a slightly different design of wire mesh electrode. The hydrodynamic model for EHD enhancement of CHF cannot reconcile the differences.A theoretical model has been developed for the growth of a single vapour bubble on a superheated wall in an electric field, leading to a numerical simulation based on the level-set method. The model includes matching of sub-models for the micro-and macroregions, conduction in the wall, distortion of the electric field by the bubble, the temperature dependence of electrical properties and free-charge generation. In the present form of the model, some of these effects are realised in an approximate form. The capability to investigate dry-spot formation and wall temperature changes that might lead to CHF has been demonstrated.

show abstract

“…Then, the dry spots coalesce with each other and a CHF occurs. However, the dry spot formation mechanism in their model is not consistent with the experimental observations by Chung and No [6]. Kolev [4] considered the fluctuation frequency as a function of the bubble departure frequency.…”

Section: Introductionmentioning

confidence: 81%

“…As described in the previous section, Chung and No [6] presented a directly observed CHF mechanism for a pool boiling of R-113 on a horizontal surface. In their experiment, a CHF was defined as the highest heat flux that the heater surface temperature was maintained as stable before a temperature excursion commenced by a slight increase in the heat flux.…”

Section: Observation Of Chf Mechanismmentioning

confidence: 87%

“…In addition, Chung and No [6] experimentally investigated a dry spot formation mechanism and the role of a dry area under a large vapor mass. They found that an increased resident time of the large dry area in the local vapor film regime influences the heat transfer mechanism and, consequently, the slope of the boiling curve apparently changes.…”

Section: Concept Of the Nucleate Boiling Fractionmentioning

confidence: 99%

See 1 more Smart Citation