Effect of adding seed nuclei on acoustic agglomeration efficiency of natural fog

Abstract

Acoustic agglomeration is a promising weather modification technology. The existing simulation and experimental studies on acoustic wave fog dissipation show that the time required to achieve the ideal agglomeration effect is basically 100 s or even 1000 s and above. The timeliness of fog dissipation operation is poor. Based on the particle population balance model, this paper simulated the effect of external seed nuclei on acoustic agglomeration under the condition of natural fog. The simulation results show: the addition of large particle swarm has a great promotion on fog dissipation. 1) When large particles are added beyond the original range of droplet spectrum, the agglomeration efficiency increases with the increase of seed nuclei concentration, and the agglomeration promotion rate can reach up to 81.99%. Complete agglomeration only need 2 min. 2) When large particle sizes are within the range of the original droplet spectrum and the concentration of the seed nuclei swarm is higher than the original concentration, the agglomeration efficiency increases with the increase of nuclei's concentration; When the concentration of the added seed nuclei swarm is lower than the original concentration, there exists an optimal concentration, which is 1/10 of the original concentration. At this time, the concentration of the added particles is low and the agglomeration time is reduced by nearly half. 3) The addition of small particles has no obvious promoting effect on agglomeration, and becomes weaker with the increase of concentration.