Analytical study on mechanism of countercurrent flow limitation in vertical rectangular channels
A quantitative analysis of countercurrent flow limitation (CCFL) or flooding was successfully carried out using the existing experimental data for the vertical rectangular channels, adopting the criterion that the CCFL condition is determined by maximizing the falling water mass velocity with respect to the thickness of falling water film for the whole flow channel, without any additional conditions. It was found that significant factors were the flow pattern, that is, which walls were wet, interfacial friction factor between liquid and gas based on the relative velocity, wall friction factors for laminar, transition, and turbulent flow of liquid and gas, and aspect ratio of rectangular channels. Thus it was clarified that the analytical results give good predictions of the existing experimental data of air-water system for vertical rectangular channels of 33 and 66 mm in channel width, 2.3 to 12.3 mm in channel gap, and 362 and 782 mm in channel length under atmospheric pressure.
- OSTI ID:
- 78230
- Journal Information:
- Heat Transfer - Japanese Research, Journal Name: Heat Transfer - Japanese Research Journal Issue: 4 Vol. 23; ISSN 0096-0802; ISSN HTJPAU
- Country of Publication:
- United States
- Language:
- English
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