Effect of a filamentary discharge on the particle trajectory in a plane-to-plane DBD precipitator

N. Zouzou (1) , E. Moreau (1)

1 PPrime [Poitiers] - Institut Pprime [UPR 3346]

In this paper, particle velocity fields inside a plane-to-plane Dielectric Barrier Discharge (DBD) precipitator is investigated using time-resolved Particle Image Velocimetry (PIV). The main objective is to analyze the effect of a filamentary discharge on the particle trajectory. A sine wave high voltage (24 kV, 30 Hz) is applied to create a DBD inside a planar gap (6.4 mm) filled with particles with a mean size of about 0.28 µm. The time-averaged velocity of the flow in the center of the channel is about 1 m/s. After the establishment of the discharge several filaments cross the gap, which induce a strong effect on the particle trajectory. During a complete period of the voltage, successive phenomena are observed. Before the first filament propagation, the shape of the velocity profiles is typical of a laminar flow. At the early stage following the filament propagation across the gap, the grey-level images show a sudden disappearance of the particles at the same location where the filament takes place. This is due to the fast precipitation of particles. During the positive half-cycle, the particles migrate mainly toward the grounded electrode due to their positive net charge. At the end of a half-cycle, the polarity of the electric field is reversed then the particles initially charged return toward the channel center. Consequently, the particles oscillate delaying their collection.

Mots clés: Physical Sciences

N. Zouzou, E. Moreau. Effect of a filamentary discharge on the particle trajectory in a plane-to-plane DBD precipitator. Journal of Physics D: Applied Physics, 2011, 44 (28), pp.285204. ⟨10.1088/0022-3727/44/28/285204⟩. ⟨hal-00633993⟩