Periodic Convective Processes in a Magnetic Fluid in Vertical Channels

Resumo

The reasons for the experimentally observable periodic transitions between two possible magnetic fluid flow directions in vertical connected channels heated from below are analyzed. It is shown that the key role is played by thermal diffusion of colloid particles due to the horizontal temperature gradients in the cross-sections of the narrow channels. On one hand, convection favors fluid mixing and, on the other hand, it itself generates concentration inhomogeneities. The gravitational sedimentation of the particles is excluded from the list of possible reasons of these oscillations.