Relative motion between phases of a particulate suspension

Measurements by a laser phase Doppler particle analyzer (PDPA) were made on a gas-solid suspension in pipe flow with the addition of tracer particles for the motion of the gaseous phase. Determinations consisted of the local instantaneous velocities and intensities of the phases and those of their relative motion. In addition to the density distribution of the particle cloud, these properties have an important bearing on the transport processes between the phases. (C) 1998 Elsevier Science S.A.