## Thermal convection

A thermal flow between a hot and a cold plate, with periodic side walls, this problem leads, at low Rayleigh number, to Rayleigh-Taylor convection rolls. In the present 2D application, the Rayleigh number is however large, and the resulting flow is unstable.

## Heated Sphere in a Channel

The unsteady transient flow around a sphere placed in a rectangular channel is presented. The Reynolds number is equal to 420. Thermal convection is also simulated, since the sphere has a constant temperature which is higher than that of the surrounding fluid. The Prandtl number is 1.2 This problem may seem simple, but it is quite difficult, since at this Reynolds number a complex flow pattern is formed downstream the sphere, as shows in the animations that follow.