Gas bubble motion in a Newtonian liquid in the field of centrifugal forces

The velocity of air bubbles in Newtonian liquids moving due to centrifugal forces in a centrifuge was investigated. The comparison of experimental res ults with a model in which free bubble surface was assumed, reveals that wi thin the range of dimensionless diameters defined by Eq. (2) acid smaller t han 2, the bubble surface hardens during the motion which results in a velo city decrease. A comparison of the results with relationships determining t he motion induced by gravity forces shows that the Bond criterion which des cribes transition from the rigid to free surface state can be generalized t o the field of the centrifugal forces.