The velocity of rise of distorted gas bubbles in a liquid of small viscosity

The terminal velocity of rise of small, distorted gas bubbles in a liquid of small viscosity is calculated. Small viscosity means that the dimensionless group gμ 4 /ρ T 3 where g is the acceleration of gravity, μ the viscosity, ρ the density and T the surface tension, is less than 10 −8 . It is assumed—and the numerical accuracy of the assumption is discussed—that the distorted bubbles are oblate ellipsoids of revolution. The drag coefficient is found by extending the theory given recently (Moore 1963) for the boundary layer on a spherical gas bubble. The results are in reasonable quantitative agreement with the experimental data.