Abstract
The turbulent field in a dilute suspension of solid particles, agitated by a pitched-blade turbine pumping downwards in an agitated tank, is investigated experimentally. A three-dimensional phase-Doppler anemometer is used to measure local, instantaneous, three-dimensional velocities of the fluid and of the suspended particles. A shaft encoding technique is used to resolve the turbulent fluctuations from the periodic velocity fluctuation due to the impeller blades, and to provide a more detailed information about the variations in flow and particle concentration. The solid particles diverge from the flow especially below the agitator close to the tip where the strongest turbulence is found. Periodic fluctuations in the particle concentration relate to the variations found in the mean velocity and in the fluctuating velocity.
