静止液中における単一大気泡周囲液相部のPIV計測

抄録

The Particle Image Velocimetry(PIV) method was applied to obtain the velocity profile around a large bubble in stagnant water in a vertical pipe of inner diameter D=26.5 mm, especially, in thin liquid film by magnifying the image and wake region. The results obtained PIV were confirmed following characteristics of the velocity profile of large bubble. The velocity profile was unaffected by an initial bubble length. With approaching rear of the large bubble, the axial velocity increases in the liquid film. Maximum velocities in the liquid film well agreed with those of the free falling model. In the wake region, the symmetric and asymmetric vortex were observed and their transition were related with the bubble length. The wake length decreases with the increase of the bubble length.