Velocity measurements in multiphase flow by means of particle image velocimetry

In this paper the principle of particle image Velocimetry and its applicati on to measuring velocities in multiphase systems (liquid/solid) and the flo w around bubbles rising in water is described. The aim of the measurements in the multiphase system is to simultaneously determine the velocity distri butions of the individual phases. A digital mask technique is used for sepa rating the information resulting from the different phases present in the s ystem.