Turbophoresis is the tendency for particles to migrate in the direction of decreasing turbulence level.
The principle tends to segregate particles entrained in high velocity gases axially toward the wall region.
Caporaloni et al. (1975)[1] first found that because the vertical gradient of turbulence near a depositing surface is large, turbophoresis is expected to enhance rate of particle deposition onto the surface.
He predicted that this would lead to a buildup of concentration near the wall, a feature which has been observed both experimentally and in Direct Numerical Simulation (DNS).
Dasgupta et al., (1997)[3] demonstrated that the non-uniform cross-sectional particle distribution observed during high-velocity flow of gas-particle mixtures through a vertical duct is indeed driven by turbophoresis.