Near-Wall Flow Induced by Large Bubbles Rising in Flat Channels

0345176 - ÚCHP 2011 SK eng C - Konferenční příspěvek (zahraniční konf.)
Tihon, Jaroslav - Pěnkavová, Věra - Vejražka, Jiří
Near-Wall Flow Induced by Large Bubbles Rising in Flat Channels.
Proceedings. Bratislava: Slovak University of Technology, 2010 - (Markoš, J.), s. 133. ISBN 978-80-227-3290-1.
[International Conference of Slovak Society of Chemical Engineering /37./. Tatranské Matliare (SK), 24.05.2010-28.05.2010]
Grant CEP: GA ČR GA104/08/0428
Výzkumný záměr: CEZ:AV0Z40720504
Klíčová slova: two-phase flow * inclined channel * single large bubbles
Kód oboru RIV: CI - Průmyslová chemie a chemické inženýrství

The motion of single air bubbles in an inclined flat water channel is investigated experimentally. The electrodiffusion technique of near-wall flow diagnostics is applied to measure the wall shear stress distribution under large bubbles rising along the upper channel wall. The directionally sensitive, two-strip electrodiffusion probes are used to detect the location of flow reversal in a thin liquid film separating the moving bubble from the wall. The electrodiffusion measurements are synchronized with the visual observation of bubble movement done by a high-speed camera. The analysis of video records provides information on the bubble shape and terminal velocity. The experiments are carried out for 3 different channel heights and cover a wide range of channel inclination angles. The experimental results on bubble motion characteristics obtained in stagnant and upward-flowing liquid arrangements are confronted with the recent predictions and scaling provided by theoretical models.
Trvalý link: http://hdl.handle.net/11104/0186504