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TOMAN, F. KRACÍK, P. POSPÍŠIL, J.
Original Title
INFLUENCE OF SHEAR STRESS ON THE LIQUID FILM FLOW IN VERTICAL TUBE
Type
conference proceedings
Language
English
Original Abstract
When a vapour is condensing in the vertical tube, the resulting condensate produces a resistance to heat and mass transfer. The thermal resistance is dependent on the thickness and character of the flow of the condensate liquid film. The integrity of film collapse due to gravity when it flows down along the tube walls and thereby waves are created in film. Because of this waves, the shear stress is produced at steam-liquid interface by vapour movement. Due to this stress, concurrent flow of the steam accelerates the film and slows down in case of countercurrent flow. This work deals with the experimental verification of theoretical mathematical models describing the behaviour of the film. The experiment was focused on the effect of shear stress of the flowing gaseous medium (air) on the thin liquid film flowing on the wall of the glass tube. The influence of shear stress has been investigated by increase of water film flow so as to maintain a constant film thickness. The influence of the flow was tested for three different pipe diameters and for the concurrent and countercurrent flow configuration. The experiment includes the determination of the upper limit of film flow for a given velocity of air flow when the film starts to pulse and the lower limit of the film flow when the condensate film breaks down and does not flow by the whole circumference of the tube.
Keywords
condensate film, stability, film flow
Authors
TOMAN, F.; KRACÍK, P.; POSPÍŠIL, J.
Released
9. 4. 2019
Publisher
Brno University of Technology, Faculty of Mechanical Engineering
Location
Brno
ISBN
978-80-214-5733-1
Book
13th International Conference for Young Researchers and PhD Students, Proceedings of the abstracts
Edition
1
Edition number
Pages from
56
Pages to
Pages count
BibTex
@proceedings{BUT157372, editor="Filip {Toman} and Petr {Kracík} and Jiří {Pospíšil}", title="INFLUENCE OF SHEAR STRESS ON THE LIQUID FILM FLOW IN VERTICAL TUBE", year="2019", series="1", number="1", pages="56--56", publisher="Brno University of Technology, Faculty of Mechanical Engineering", address="Brno", isbn="978-80-214-5733-1" }