On the distribution of particles during convection of colloids in narrow vertical channels heated from below

Abstract

We analyze the stationary distribution of particles during the convection of a colloid with positive thermodiffusion in bottom-heated vertical channels. The redistribution of the colloid particles in the cross-section of the channels, in both ascending and descending flows, occurs due to thermodiffusion under the influence of the harmonic temperature profile generated by thermal convection. Vertical particle flows, arising due to thermodiffusion under the influence of the applied temperature gradient and gravitational field (sedimentation), do not lead in infinite channels to vertical redistribution of particles and therefore do not affect convection. This is due to the absence in infinite channels of obstacles for particles in the form of the upper and lower boundaries, where the concentration inhomogeneities could begin to grow.