Theory of aerosol particle Thermal deposition on a flat body in a variable property fluid

Formulation for predicting deposition velocity of particles in turbulence

“…A constant thermophoretic coefficient K th z 0.55 has been concluded to be applicable for the particles in transition regime K n z 1 and free molecule flow regime K n [ 1, which represents that the thermophoresis in the regions is independent of thermal conductivity ratio and has its largest effect [33]. It has been obtained that, when the particle size involved falls in the continuum regime K n ( 1.0, the effect of thermophoresis is significantly enhanced with reduced heat conductivity in particles because the thermophoretic coefficient K th decreases continuously with increasing particle sizes [34]. This has been explained by considering that the thermophoretic mechanism for larger particles is subjected to the gas slipping along the nonuniformly heated particle surface, where the nonuniformity is stipulated by the temperature gradient of gas and strongly depends on the thermal conductivity of particles [35].…”

Turbulent thermophoresis effect on particle transport processes

“…Goren [13] was the first one to theoretically demonstrate that the solid particle deposition onto a cold solid wall in the presence of thermophoretic effect. The numerical results of thermal deposition of aerosol particles on a flat body indicate that the deposition flux decreases with increasing surface temperature and increases nonlinearly with increasing thermophoretic coefficients [14]. Modeling clusters deposition in the thermal plasma flash evaporation process shows that the concentration boundary layer is significantly suppressed by the thermophoretic force, and that the thermophoresis plays a dominate role than that of diffusion giving rise to an uniform deposition efficiency for different cluster sizes (1-10 nm) [15].…”