On the importance of thermophoresis and Brownian diffusion for the deposition of micro- and nanoparticles

The aim of the present paper is to analyze the importance of thermophoresis as well as Brownian diffusion for the deposition of micro- and nanoparticles in the presence of temperature gradient. A hybrid Eulerian–Lagrangian procedure is invoked to evaluate the air flow and temperature distribution as well as particles dispersion and deposition. Inspection of the results indicates that, the dominant mechanism for the deposition of ∼ 100 μm particles belongs to inertial impaction. The results reveal that, ∼ 10 μm particles are mainly influenced by thermophoresis. For finer particles (10 nm < particle < 1 μm), it is demonstrated that, depending upon temperature gradient, varied degrees of thermophoresis and Brownian diffusion may contribute on the particle deposition. Nevertheless, as temperature gradient increases, the relative role of thermophoresis enhances.