Lift coefficient of bubble sliding inside turbulent boundary layers in an inclinable channel flow

The behavior of bubbles traveling in the proximity a tilted wall is studied experimentally to understand fundamental sliding motion inside turbulent boundary layers along an inclined wall. qualitative visualization confirms contribution bubble buoyancy on for negative and positive inclinations channel. An opto-acoustic combined measurement technique adopted explore motion. Liquid velocity profiles bubbly flow distance between bottom are obtained using ultrasound pulsed Doppler method, while diameters velocities from particle-tracking type image processing. measurements reveal that decreases under slope condition increases due opposite effects. In addition, with increase inclination. lift coefficient derived measured variables force–balance equation among buoyancy, lift, surface tension. Finally, we propose modeling equations expressed terms Reynolds, Weber, Bond numbers, which apply layers.