Thermophoretic effects on nano-particle deposition in channel flow

In this study, deposition of particles with diameters of 3, 5, and 10 nm in a finite-length heated channel flow is numerically studied under both molecular diffusion and thermophoretic effects. Two types of thermal conditions were examined. The first condition involved various inlet temperatures with a fixed wall temperature. The second condition involved various wall temperatures and a fixed inlet temperature. For a finite channel length, higher particle deposition can be obtained for the various inlet temperature and fixed wall temperature cases. However, for the same temperature ranges, complete particle collection on the wall can only be achieved under various wall temperatures and fixed inlet temperature cases when the channel length is long enough. This is because a temperature gradient appears in these cases. The temperature gradient in the various inlet wall temperatures and fixed wall temperature cases is zero when the flow is thermally fully developed.