Single particles, bubbles and drops: Their velocities and mass transfer coefficients

This article is about single particles, bubbles and drops. It considers the ir falling (or rising) velocities and mass transfer coefficients. These are presented as graphs of dimensionless groups; the groups are chosen such th at the graphs can be recognized as plots of a velocity against a diameter. The result is more intuitive than are plots using the traditional dimension less groups such as the Reynolds, Sherwood and Schmidt numbers.