Nonlinear Physics Lab


Shear band instability in the

presence of convection.*

A. Stettler , S. Aumaitre and J.P. Gollub, Haverford Coll.


One of the main features of the atmospheric motion of giant gas planets, like Jupiter and Saturn, is their remarkably stable shear band structure. The stability and internal structure of this flow, and the consequences for the internal heat transport, are not fully understood. We built a flexible device (see the experimental device) to study in a laboratory experiment the stability of a shear band flow in the presence of convective heat transport. The shear band flow is generated in layer of conductive fluid by spatially periodic Lorentz forces resulting from an electric current passing through the fluid in the presence of a network of magnets placed under the cell (more on the Kolomogorov Flow). Moreover, a convective flow is created by an imposed temperature gradient across the fluid layer. By changing the current through the fluid, and the temperature difference across the layer, we are able to adjust independently the velocity fields resulting from the shear and thermal forcing. Furthermore, heat transport, flow patterns, and velocity fields can be monitored.

*Supported by NSF-DMR -0405187.