2 METHODS IN LARGE AEROSOL-PARTICLE THERMOPHORESIS THEORY

The method suggested by L. Waldmann (Z. Naturforsch. A 22, 1269 (1967)) has been applied to the formulation of the boundary conditions for the determination of temperature and velocity fields of a gas flowing around a sphere of sufficiently large radius in the pressure range where correction for slip is quite essential. An expression for the thermophoretic velocity of such a sphere has been derived by direct calculation. A new variant is proposed here for the application of the principles of irreversible thermodynamics to the calculation of the velocity of large aerosol particles. The expression so obtained coincides with the expression obtained by the direct method. The distinction between the formulas obtained here for the thermophoretic velocity and the previously reported expressions is analyzed. © 1979 Academic Press, Inc.