Numerical investigation of thermophoretic effects on cluster transport during thermal plasma deposition process

Cluster transport and deposition processes under the effects of thermophoresis are numerically investigated in terms of thermal plasma deposition processes. The cluster transport equation is solved within a prescribed flow field, where it is assumed that clusters with a given uniform size are generated within the boundary layer. Cluster concentration and deposition flux are calculated for clusters in the size range of 1–6 nm. Results are also given for comparative cases without thermophoresis effects. It is found that the thickness of the concentration boundary layer is significantly suppressed by the thermophoretical force. The effect of thermophoresis plays a more dominant role than that of diffusion, thus an almost uniform deposition efficiency is achieved for clusters of different sizes.