Thermomagnetic convection

This video presents typical flow patterns on the thermomagnetic convection phenomenon. It was made by Prof. Rafael Gabler Gontijo at the University of Brasília, Brazil.

In the present work, we particularly focused on the flow induced by convective currents inside a cavity with aspect ratio near the unity. The currents are formed when a magnetic suspension is subjected to a temperature gradient combined with spacial variations of an externally imposed magnetic field. Under these conditions, stratifications in the suspension density and susceptibility are both important effects to the convective motion. The convection state is largely affected by new instability modes produced due to susceptibility stratification. The experiments reveal that the magnetic field enhances the instability in the convective flow leading to a more effective mixing and consequently to a more statistically homogenous temperature distribution inside the test cell, as showed by Gontijo, R.G and Cunha, F.R. in the 6th Internacional Conference on Surfaces, Coatings and Nano-Structured Material -NANOSMAT Conference - Krakow - Poland - 2011.