INVESTIGATION OF NON-SPHERICAL NANOPARTICLE SEPARATION IN SUPERSONIC IMPACTORS

In this paper, the airflow field and non-spherical nanoparticle transport in supersonic impactors were investigated and the corresponding collection efficiencies were analyzed. A series of simulations were performed using the coupled compressible Navier-Stokes and energy equations and a computer model for evaluating the Lagrangian non-spherical (with various sphericity) nanoparticle trajectories including all the relevant forces of drag and Brownian was developed. Particular attention was given to accurate analysis of Brownian motions of nonspherical nanoparticles in supersonic flows and the drag coefficient of non-spherical nanoparticles were evaluated accurately. Therefore, the importance of the accurate modelling of the drag force on non-spherical nanoparticles was further emphasized. The simulation results showed that smaller nanoparticles can be collected as the distance between the nozzle and the impactor plate increase. Besides results clearly showed the increasing influence of nanoparticle shape on drag coefficient and impactor collection efficiency with decreasing the distance between the nozzle and the impaction plate.

کلیدواژه ها:

Impactor ، Supersonic flow ، Nanoparticles ، Drag force ، Sphericity