Theory of the Motion of Inclusions in a Viscous Medium Under Joint Influence of Electromagnetism and Thermocapillarity

Abstract

The motion of a fine inclusion in a viscous medium is subjected to theoretical examination. This motion can be qualified as an elementary act of the motion of fine phase particles in mixtures: suspensions, emulsions, airsols, and foamed liquid materials. The erroneous character of the theory of thermocapillary motion of inclusions, which is universally recognized now, is revealed. It is proposed to take into account the “energy of location” of the inclusion in a nonuniform temperature field, to formulate more correctly the Stokes equation describing the velocity field inside the fluid inclusion. The solution of the set of the Stokes equations referring to a liquid particle and a surrounding medium has allowed obtaining the formula for the motion velocity of a particle under joint influence of electromagnetism and thermocapillarity. This formula is suitable for theoretical calculations of transfer processes in suspensions, emulsions, and gaseous media containing various inclusions. The calculation on inclusions in molten metals (e.g., in Cu, Al, Fe, Ag) shows that the exertions caused by electromagnetism and thermocapillarity are comparable.