Effect of the Flow Velocity of Gas on Liquid Film Flow in a Vertical Tube
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216305%3A26210%2F20%3APU137019" target="_blank" >RIV/00216305:26210/20:PU137019 - isvavai.cz</a>
Result on the web
<a href="https://www.aidic.it/cet/20/81/136.pdf" target="_blank" >https://www.aidic.it/cet/20/81/136.pdf</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.3303/CET2081136" target="_blank" >10.3303/CET2081136</a>
Alternative languages
Result language
angličtina
Original language name
Effect of the Flow Velocity of Gas on Liquid Film Flow in a Vertical Tube
Original language description
When gas flows inside a vertical tube in which a thin liquid film runs down its wall, interfacial shear stress occurs at the gas-liquid interface. This stress is caused by the imperfectly smooth surface of the film running down. For intensification of heat transfer in heat exchangers where the vapour condenses, it is necessary to pay attention not only to the thickness of the liquid film on heat exchange surface, but also the character of the liquid film. This paper describes the influence of a gas flow velocity on a liquid film flow. The gas velocity effect is examined for a constant thickness of the liquid film. When the velocity of the gaseous medium changes, it is necessary to increase or decrease the liquid flow in order to keep the film thickness constant. The effect of shear stress is described for three different inner tube diameters (15.0, 20.0, and 25.0 mm) and for three different theoretical film thicknesses derived from the Nusselt criterion. The results are compared with theoretical, analytical relationships. In all the three tube diameters tested, the influence of the gas velocity is the most significant at low speeds, where the deviation from the theoretical course is the greatest. As the tube diameter decreases, the shear stress effect increases. At higher speeds of the gas and liquid film flow, pulsations start to occur, the film flow stops increasing, and the trend follows the theoretical, analytical relationships published in the professional literature.
Czech name
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Czech description
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Classification
Type
J<sub>SC</sub> - Article in a specialist periodical, which is included in the SCOPUS database
CEP classification
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OECD FORD branch
20704 - Energy and fuels
Result continuities
Project
<a href="/en/project/EF16_026%2F0008392" target="_blank" >EF16_026/0008392: Computer Simulations for Effective Low-Emission Energy Engineering</a><br>
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)
Others
Publication year
2020
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Chemical Engineering Transactions
ISSN
2283-9216
e-ISSN
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Volume of the periodical
81
Issue of the periodical within the volume
2020
Country of publishing house
IT - ITALY
Number of pages
6
Pages from-to
811-816
UT code for WoS article
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EID of the result in the Scopus database
2-s2.0-85092019388