The determination of particle terminal and transport velocities
The movement of finely divided material in chemical process equipment is becoming the object of much present-day study. In industrial practice, the ability to predict the behavior of small bodies moving through a fluid medium or being moved by a fluid medium must be based upon data relating to physical properties of both the particle and the fluid; these physical properties should be those which can be readily determined.
A particle falling through a fluid medium will achieve a steady state velocity if it is allowed to fall until its acceleration becomes zero. This steady state rate of fall is defined as the particle terminal velocity.