## Fluid Dynamics

### Faculty involved

Alexander Balk, Yekaterina Epshteyn, Aaron Fogelson, Ken Golden, Christel Hohenegger, Jingyi Zhu.

- Dynamics of complex biofluids (with Low-Reynold’s number, active suspensions)
- Shallow water models (mathematical and computational)
- Flow in porous media (sea ice, two-phase flow models)
- Non-linear waves in fluids (Rossby waves), turbulence
- Platelet deposition and aggregation during blood clotting
- Statistical mechanics of electrorheological fluids

The rotating shallow water dynamics (on the beta-plane) has an extra invariant. The graphs above show the spectral density of the extra invariant versus the wave vector. (from “Angular distribution of Rossby wave energy” by A. M. Balk and “Rotating shallow water dynamics: Extra invariant and the formation of zonal jets” by A. M. Balk, F. van Heerden, and P. B. Weichman)

When a sufficiently strong electric field is applied to a suspension of plastic spheres in oil, they quickly form chains (above left) and then columns where the spheres are arranged in periodic lattice configurations. When the spheres are metal (above right) they form connected clusters with fractal structure (Courtesy of Ken Golden)

Webmasters: Yekaterina Epshteyn and Fernando Guevara Vasquez.