Heat transfer and flow patterns in ferrofluid convection

A. A. Bozhko , G. F. Putin

Perm State University, Perm, 614990, Russia

Abstract
Experiments were performed to examine the influence of an external homogeneous magnetic field -- transversal or longitudinal -- on ferrofluid convection in horizontal, inclined and vertical layers. The integral and local temperature sensors were used for measuring the heat transport across the layer. The flow patterns were visualized by a temperature-sensitive liquid crystal sheet. The results indicate that with the help of a magnetic field it is possible to control the stability and the form of convective motions. A number of non-linear regimes of convection, e.g., spiral-defect chaos, blinking and localized states were observed. The repeated long-wave transients from Rayleigh convection to pure conduction in the case of a horizontal enclosure and to a shear flow under inclination were also revealed. Figs 31, Refs 41.